taxonID	type	description	language	source
03C887CFFFB6FFFBFF4BFEC54DD7FEDE.taxon	description	This taxon has been described as Myrmica (Monomarium) [sic!] minima Buckley 1867 from Texas. Buckley (1867) gave only the terra typica: “ Common in Central Texas ”. According to Creighton (1950) and DuBois (1986) no type material could be identified in any collection in the USA including that of the Academy of Sciences Philadelphia. Accordingly, DuBois (1986) fixed a neotype for Monomorium minimum (Buckley) in a winged gyne from Texas labelled “ Bastrop St. Pk., Tex. June 9, 1954 W. Clayd, T- 119 ”, “ Monomorium minimum (Buckley) Neotype M. DuBois 1983 ” and “ M. C. Z. NEOTYPE 32921 ”, depository MCZ Cambridge. Unfortunately there is no worker material associated to the neotype to have a more reliable classification. Monomorium carbonarium develops large and small winged gynes (see Tab. 5). The latter are most similar to winged gynes of M. ergatogyna and the neotype with CS = 0.736 mm may belong to both species (Tab. 5). Twelve worker-associated small winged gynes of M. carbonarium but only two worker-associated winged gynes of M. ergatogyna were available for comparison. Running the neotype of M. minimum as wild-card in a stepwise LDA considering all characters shown in Tab. 5 it is allocated to M. carbonarium with p> 0.98. Yet, this is a weak suggestion because of strong character overfitting and the high variance and small sample size in the comparison samples. A better argument in favor of a synonymization with M. carbonarium is its higher abundance in Texas: 11 evaluable worker samples of Monomorium, all collected before 1947, were available from Texas of which 91 % belonged to M. carbonarium and only 9 % to M. ergatogyna. The situation today may differ. The third supporting argument is the higher frequency of winged gynes in the studied Nearctic material of M. carbonarium: the ratio of winged gynes vs. wingless gynes was 14: 5 in M. carbonarium but 2: 24 in M. ergatogyna. These arguments multiply to a fair probability that M. minimum from Texas should be a junior synonym of M. carbonarium. A really convincing argumentation is not possible at the current stage.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFB6FFFBFF4BFEC54DD7FEDE.taxon	description	This taxon has been described from Globe / Arizona (holotype series) and Austin / Texas (paratypes) and San Marcos / Texas (paratypes). In NMNH Washington are 1 paratype winged gyne plus 51 worker paratypes on 17 pins all labelled “ Austin Tex. IV- 6 - 1937 A Emerson ” [printed] and “ Monomorium minimum emersoni subsp. nov. R. Gregg det R Gregg ” [hand-written by Gregg himself]. As it is not clear if this large material represents a nest sample, two worker series with remote placement in the box and the gyne were morphometrically investigated. The gyne data allow no decision – is either a small winged gyne of M. carbonarium or a winged gyne of M. ergatogyna. However, the two worker series were allocated to M. carbonarium with p = 0.9999 and 0.9982. Nevertheless, the synonymization with M. carbonarium stated here is risky as the holotype series from Globe was not studied. Based on abundance of species in the region the holotype series could also belong to M. ergatogyna or M. emarginatum. If belonging to the latter, M. emersoni would become a senior synonym. The holotype series from Globe was not available.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFB6FFFBFF4BFEC54DD7FEDE.taxon	description	This taxon has been described from Gainesville in Alachua County, Florida based on a nest population collected from beneath a board in a cow pasture. The specimens investigated from the holotype nest are as follows. Holotype wingless gyne labelled “ Florida: Alachua C., Gainesville April 5, 1980 J. C. Trager ” and “ Monomorium trageri Holotype M. Dubois 1983 ”; 1 paratype wingles gyne, 1 paratype worker with same locality label, depository NMNH Washington. 1 worker and 1 wingless gyne from holotype nest labelled “ Florida: Alachua C., Gainesville April 5, 1980 J. C. Trager ” and “ Monomorium trageri Paratype M. DuBois 1983. ” [blue, bleached label, year not clearly visible], depository AMNH New York. 1 worker and 1 wingles gyne from the holotype nest labelled “ Florida: Alachua C., Gainesville April 5, 1980 J. C. Trager ” and “ Monomorium trageri Paratype M. DuBois 1983. ” [blue, bleached label, year not clearly visible], depository CAS San Francisco. The wingless gyne from CAS has a malformed propodeum and waist segments and is not included in the analysis. Monomorium trageri is synonymized here with M. carbonarium because the worker sample is allocated to the M. carbonarium cluster with p = 0.9989 if run as wild-card in a LDA and because the three evaluable type wingless gynes are placed in a PCA close to wingless gynes of M. carbonarium (Fig. 7). For more details see below under Taxonomic Comments.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFB6FFFBFF4BFEC54DD7FEDE.taxon	materials_examined	All material examined. Numeric phenotypical data were taken in 45 samples with 141 workers and 27 gynes. The material came from France (12 samples), Germany (1), Mexico (1), Netherlands (3), Portugal (3) and USA (25). For details see supplementary information SI 1, SI 2 and SI 3. Geographic range. Widely distributed over the USA south to Mexico. Introduced to West and Central Europe. Altitudinal records range from sea level up to 2900 m (at 20 ° N in Mexico).	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFB6FFFBFF4BFEC54DD7FEDE.taxon	description	Description: - - Worker (Tab. 3; Figs. 23, 24; key). Very small, CS 470 ± 22 µm. Head moderately long, CL / CW 1.191 ± 0.027. Dents on clypeal margin moderately long (ExCly / CS 4.80 ± 0.58 %), not very acute and moderately distant (ClSpD / CS 11.42 ± 0.97 %). Frontal carinae moderately distant and slightly diverging frontad (FL / CS 0.285 ± 0.008, FR / CS 0.276 ± 0.008, FL / FR 1.031 ± 0.021). Eye and preocular distance moderately large (EL / CS 0.205 ± 0.007, PrOc / CS 0.224 ± 0.010). Scape and funiculus segments moderately long (SL / CS 0.807 ± 0.021, Fu 2 / CS 6.38 ± 0.21 %, Fu 3 / CS 4.82 ± 0.25 %). Mesosoma rather short but relatively wide (ML / CS 1.179 ± 0.028, MW / CS 0.581 ± 0.014). Metanotal groove moderately deep, MGr / CS 5.24 ± 0.66 %. Dorsum and slope of propodeum in profile forming a convex curve. Petiole rather wide and high (PeW / CS 0.289 ± 0.018, PeH / CS 0.378 ± 0.013). Postpetiole moderately wide and rather high (PpW / CS 0.316 ± 0.017, PpH / CS 0.294 ± 0.011). All body surfaces with exception of few rugulae on frontal lobes, ventral mesopleuron, ventrolateral area of metapleuron and genae glabrous and shiny. All body parts homogenously dark brown to jet black; mandibles, lateral clypeus and antennal funiculus lighter brown. -- Gyne (Tabs. 4, 5): The Nearctic population is extremely polymorphic in gynes, developing winged and wingless gynes with strong size variation in each morph. The sparse material available does not allow to propose diagnostic determination characters. The large winged gynes are probably better to identify as a combination of short scape and long petiole (Tab. 5). Taxonomic comments. The description above does not present a single diagnostic character which results in the uncomfortable situation that species delimitation from M. ergatogyna and M. gallicum n. sp. is only possible by multivariate analyses. A species hypothesis was formed by NC-part. hclust considering the 12 characters CS, CL / CW, SL / CS, EL / CS, ClSpD / CS, MW / CS, PpW / CS, PeH / CS, PeL / CS, PpH / CS, MGr / CS, Fu 3 / CS. Within a total of 96 samples, it proposed three clusters and five outliers. In the controlling LDA, these clusters were accepted as species hypothesis and the outliers were run as wild-cards. The final species hypothesis of these runs is given in Fig. 33. It indicated that NC-part. hclust misclassified only one sample of M. gallicum n. sp. whereas the clusters later identified as M. ergatogyna and M. carbonarium were incompletely separated (Fig. 31). This result was repeated by a PCA in which M. gallicum n. sp. formed a well separated and constricted cluster (Fig. 32). One sample of M. carbonarium that approached M. gallicum n. sp. cluster was run as wild-card in the LDA and confirmed as the former species. In order to improve the separation of M. carbonarium and M. ergatogyna, M. gallicum n. sp. was excluded from analysis and NC-part. hclust was run using the 11 characters FR / CS, PeH / CS, SL / CS, ClSpD / CS, PpW / CS, MGr / CS, PeW / CS, EL / CS, PpH / CS, FL / CS, MW / CS. The analysis proposed two clusters and seven outliers within a total of 73 samples (Fig. 34). The final species hypothesis indicated that NC-part. hclust misclassified two samples. A PCA and NC-NMDS. kmeans run with the same data misclassified three and five samples respectively. Note: The cluster named above M. carbonarium was divided by NC-part. hclust into three subclusters. I decided to give these sublusters no taxonomic rank because NC-part. hclust tends to oversplit and because the resulting sample size of these subclusters became too small to reasonably check the data by the controlling LDA. Anyway, these data show the need for further research and that some of the synonymizations proposed in this paper under M. carbonarium might possibly be reversed.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFB6FFFBFF4BFEC54DD7FEDE.taxon	biology_ecology	Biology. The unresolved species delimitation in the past does not allow to use literature sources on life history and habitat selection referring to the situation in the New World. Some 200 samples in American museum collections labelled by DuBois as “ Monomorium minimum ” are a random mixture of M. carbonarium, M. ergatogyna and M. emarginatum. These three species are abundant and widely distributed in the USA which prevents any probabilistic interpretation of published biological data based on zoogeography. The more advanced species delimitation presented here and published information on particular classified samples allows to extract some fragments of life history: M. carbonarium is extremely gyne polymorphic in America with the winged gyne most certainly representing an ability for long-range flight-dispersal and independent colony foundation. Most colonies seem to be polygynous. Winged gynes are present in polygynous colonies but the wingless gynes are the dominant gyne morph in very polygynous (in Europe supercolonial) colonies. In a polygynous colony from Gainesville / Florida (type location of M. trageri), 10 % of the queens were winged gynes and 90 % wingless gynes and the latter were mated intranidally (DuBois 1986). All over the USA, young winged gynes with wings and males were found in the nests from 6 June to 24 July with the bulk in July. Wingless gynes were observed to perform female calling, dispersed on the whole plant of a waist-high Ailanthus bush and were accompanied by a retinue of workers. One to multiple alate males engaged on a single female but the mating count was uncertain (SaNo 141, 24 June 2023, Washington D. C., Brendon Boudinot pers. comm. 2024). Only wingless gynes are known so far from Madeira and West Europe which seems to contrast the very polymorphic situation in the Nearctic. This reduction to wingless gynes and the very recent occurrence as invasive pest ant in urban areas of West Europe support the assumption that the European population was founded by introduction from America. Supercoloniality has not been reported so far from the USA but in five of the 16 European locations. One supercolony in a greenhouse in the Netherlands caused a lot of problems there and another supercolony in a school yard in southern France expanded its territory by 18 m within a year. The distribution over main habitat types in Europe was 14 findings in urban, semi-urban or rural habitats and 2 findings in “ natural ” habitats (i. e., habitats with lowest anthropogenic influence such as coastal grey dunes or pastures). This distribution seems to differ from the situation in the sympatric and biologically very similar Monomorium gallicum n. sp. where 16 findings were made in the first habitat group but 7 in the latter. The soil of the urban habitats can be fully sealed with almost no vegetation being present. Monomorium ergatogyna Wheeler 1904	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFABFFFBFF61FE834E46F843.taxon	description	This species has been described from Catalina Island near Los Angeles based on “ numerous workers and eight females taken from three different nests ” (Wheeler 1904). Morphometrically investigated were 5 syntype wingless gynes and 6 syntype workers from AMNH New York labelled: “ Catalina I Cala. C. F. Bak- er ”, “ TYPE nO A. M. N. H. ” “ Monomorium ergatogyna Wheeler Paralectotype M. DuBois 1981 ”. The workers from the type sample are allocated to the Monomorium ergatogyna cluster with p = 0.9936 in a wild-card run of a 3 - class LDA considering the species Monomorium carbonarium, M. ergatogyna and M. gallicum n. sp. and all 19 numeric characters of workers (Tab. 1). The five wingless type gynes are well separated in a PCA from the two next similar species (Fig. 7).	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFABFFFBFF61FE834E46F843.taxon	description	This taxon has been described from Wheeler Spring in the Spring Mountains, Clark County in Nevada, 2012 m based on material collected by G. C & J. Wheeler. Investigated was the holotype wingless gyne labelled “ NEVADA: Clark Co. WHEELER SPRING SPRING Mts., 6600 ’, APRIL 1 1971 G. + J. Wheeler 1561 ”, “ LACM ENT 164441 ” and “ Monomorium wheelerorum Holotype M. DuBois 1983 ”; 1 paratype worker from holotype nest on another pin with same collecting data and “ LACM ENT 275330 ”, and “ Monomorium wheelerorum Paratype M. DuBois 1983 ”; depository Los Angeles Country Natural History Museum. 1 paratype wingless gyne and 2 paratype workers labelled “ NEVADA: STOREY Co. OPHIR GRADE, 2 mi WSW VIRGINIA CITY, 8 JULY 1971 6500 ’, G. + S. WHEELER 2280 ”, “ Monomorium wheelerorum Paratype M. DuBois 1983 ”, depository NMNH Washington. The worker of the holotype sample is allocated to the Monomorium ergatogyna cluster with p = 0.9999 in a wild-card run of a 3 - class LDA considering the species Monomorium carbonarium, M. ergatogyna and M. gallicum n. sp. (Tab. 1). A similarly clear allocation with p = 0.9969 is also given for a sample of four workers from Wheeler Springs summit (close to the holotype locality) and the two paratype workers from Ophir Grade (p = 1.0000). The wingless holotype gyne was placed in a PCA within the cluster of wingless M. ergatogyna gynes considering all numeric characters (Fig. 7).	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFABFFF8FCE4FF414DC5FA38.taxon	description	This taxon has been described from the state of Hidalgo, Mexico based on “ numerous workers and females taken at Guerrero Mill under stones in rather damp places on the sides of the canyons ” (Wheeler 1914). Morphometrically investigated was a paratype wingless gyne plus three paratype workers labelled “ Guerrero Mill. Hidalgo. Mexico W. M. Mann ”, “ PARATYPE ”, “ WM Mann 1954 Collection ”; depository NMNH Washington. The three paratype workers were allocated to the Monomorium ergatogyna cluster with p = 0.9965 in a wild-card run of a 3 - class LDA considering the species Monomorium carbonarium, M. ergatogyna and M. gallicum n. sp. (Tab. 1). The paratype wingless gyne was placed within the M. ergatogyna cluster in a PCA (Fig. 7). Note: There are some 180 workers in NMNH Washington labelled by DuBois as paratypes of Monomorium cyaneum. These belong to two species (see Tab. 1) and cluster either with M. ergatogyna or M. carbonarium. Since the lectotype gyne (designated by DuBois 1986) and workers associated to this gyne were not investigated, it cannot be excluded that M. cyaneum is instead a junior synonym of M. carbonarium. However, because the ratio of M. ergatogyna vs. M. carbonarium in morphometrically investigated worker samples from Mexico as a whole was 5: 1, the synonymization stated above appears more probable.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFABFFF8FCE4FF414DC5FA38.taxon	materials_examined	All material examined. Numeric phenotypical data were taken in 30 samples with 95 workers and 26 gynes. The material came from Mexico (4 samples) and the USA (26 samples). For details see supplementary information SI 1, SI 2 and SI 3 .. Geographic range. Widely distributed over the USA south to Mexico and overall more frequent than M. carbonarium. Vouchers from the USA include the states California, Nevada, Idaho, Texas, Mississippi, Tennessee and Virginia. Altitudinal records range from sea level up to 2900 m (at 20 ° N in Mexico).	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFABFFF8FCE4FF414DC5FA38.taxon	description	Description: -- Worker (Tab. 3; Figs. 23, 24; key). Very small, CS 464 ± 21 µm. Head moderately long, CL / CW 1.204 ± 0.024. Dents on clypeal margin moderately long (ExCly / CS 4.58 ± 0.68 %), not very acute and moderately distant (ClSpD / CS 10.38 ± 0.96 %). Frontal carinae moderately distant and slightly diverging frontad (FL / CS 0.274 ± 0.008, FR / CS 0.263 ± 0.008, FL / FR 1.041 ± 0.026). Eye and preocular distance moderately large (EL / CS 0.199 ± 0.009, PrOc / CS 0.224 ± 0.009). Scape and funiculus segments moderately long (SL / CS 0.817 ± 0.022, Fu 2 / CS 6.36 ± 0.36 %, Fu 3 / CS 4.83 ± 0.28 %). Mesosoma short and rather narrow (ML / CS 1.161 ± 0.032, MW / CS 0.567 ± 0.015). Metanotal groove moderately deep, MGr / CS 4.63 ± 0.70 %. Dorsum and slope of propodeum in profile forming a convex curve. Petiole rather wide but moderately high and long (PeW / CS 0.282 ± 0.017, PeH / CS 0.361 ± 0.010, PeL / CS 0.425 ± 0.013). Postpetiole moderately wide and high (PpW / CS 0.317 ± 0.013, PpH / CS 0.284 ± 0.011). All body surfaces with exception of few rugulae on frontal lobes, ventral mesopleuron, ventrolateral area of metapleuron and genae glabrous and shiny. All body parts homogenously dark brown to jet black; mandibles, lateral clypeus and antennal funiculus lighter brown. -- Gyne (Tabs. 5 and 6): Both winged and wingless gynes are developed but the latter are much more frequent. The sparse material available, in particular of winged gynes, does not allow to propose diagnostic determination characters but at least the wingless gynes are separated from those of M. carbonarium and gallicum n. sp. by a PCA considering all 19 characters (Fig. 7). Taxonomic comments. The worker is very similar to M. carbonarium and does not show any diagnostic character. As result, the separation from M. ergatogyna and M. gallicum n. sp. is only possible by stepwise multivariate analyses (Figs. 31 - 34, for details see above).	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFABFFF8FCE4FF414DC5FA38.taxon	biology_ecology	Biology. The unresolved species delimitation in the past does not allow to use literature sources and I can only refer here to the sparse information connected with material determined in this revision. Wheeler (1914) reported his subspecies cyaneum to occur in rather damp and moist places within a xerothermous environment. Four nest samples collected in California by Lorenzo Fraysse (SaNo 115 - 118) were found in chaparral – twice under stones and once each under grass and in a wet mossy path embankment. Two nest samples collected in Nevada were found in semideserts. Winged gynes are much rarer than wingless gynes and young winged gynes were observed in the investigated material 2 July 1919, 26 July 1942. Monomorium compressum Wheeler 1914	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFA8FFFEFF4BF9A54D8EFBB6.taxon	materials_examined	This taxon has been described from the state of Hidalgo, Mexico based on “ four females and several workers taken at San Miguel beneath a stone ” (Wheeler 1914). Investigated were a paratype wingless gyne and four paratype workers from the holotype nest labelled “ San Miguel. Hidalgo, Mexico W. M. Mann ” and “ WM Mann 1954 Collection ”; depository NMNH Washington. The status of a different species was maintained here due to the very different gyne (Tab. 5, Figs. 6, 27, 28). The workers are in nearly all characters fully within the range of Monomorium ergatogyna or M. carbonarium (Tab. 3) but are possibly separable by multivariate analyses (see below). It is puzzling how DuBois could determine in the NMNH Washington collection worker samples from four other localities in Mexico as M. compressum since the differential characters stated in his key are useless All material examined. Only the holotype nest sample and another one with four workers were available for investigation. Geographic range. Only the holotype sample from locality San Miguel in the Mexican state of Hidalgo and the sample of four investigated workers from Mexico (city?) was available.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFA8FFFEFF4BF9A54D8EFBB6.taxon	description	Description: - - Worker (Tab. 3, key). Most similar to M. carbonarium and M. ergatogyna with almost no morphometric character being outside the range of variation of that species. The differential characters supposed below have to be checked in a larger sample. Very small, CS 453 ± 19 µm. Head more elongated than in M. carbonarium and M. ergatogyna, CL / CW 1.247 ± 0.008. Dents on clypeal marginshorterthanin M. carbonarium and M. ergatogyna (ExCly / CS 3.04 ± 0.47 %), not very acute and moderately distant (ClSpD / CS 10.12 ± 0.90 %). Frontal carinae moderately distant and very slightly diverging frontad (FL / CS 0.270 ± 0.007, FR / CS 0.266 ± 0.003, FL / FR 1.017 ± 0.012). Eye and preocular distance moderately large (EL / CS 0.206 ± 0.004, PrOc / CS 0.227 ± 0.005). Scape and funiculus segments moderately long (SL / CS 0.812 ± 0.009, Fu 2 / CS 6.13 ± 0.39 %, Fu 3 / CS 4.96 ± 0.32 %). Mesosoma longer than in M. carbonarium and M. ergatogyna and moderately wide (ML / CS 1.207 ± 0.018, MW / CS 0.561 ± 0.016). Metanotal groove rather shallow, MGr / CS 4.29 ± 0.55 %. Dorsum and slope of propodeum in profile forming a convex curve or a suggested very blunt angle. Petiole moderately wide, high and long (PeW / CS 0.260 ± 0.017, PeH / CS 0.358 ± 0.008, PeL / CS 0.428 ± 0.011). Postpetiole rather wide and moderately high (PpW / CS 0.316 ± 0.021, PpH / CS 0.276 ± 0.012). All body surfaces with exception of suggested rugulae on lateral frontal lobes, genae and ventrolateral area of metapleuron glabrous and shiny. Head, mesosoma, waist and appendages brown, gaster blackish brown. -- Gyne (Tab. 5, Figs. 27, 28): The morphometric data and images reveal a unique gyne morphology. Taxonomic comments. The unique gyne morphology should justify the status as a good species but worker identification is most difficult. In an attempt to separate the Nearctic triple Monomorium carbonarium, M. ergatogyna and M. compressum, it was possible to isolate the two samples of M. compressum by a PCA using the 13 characters FR / CS, PeH / CS, ExCly / CS, SL / CS, ML / CS, ClSpD / CS, MGr / CS, CL / CW, PpW / CS, PpH / CS, FL / FR, PeW / CS, EL / CS (Fig. 35). I consider this result as provisional.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFA8FFFEFF4BF9A54D8EFBB6.taxon	biology_ecology	Biology. Nothing is known except for polygynous colony demography. Monomorium gallicum n. sp.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFA8FFFEFF4BF9A54D8EFBB6.taxon	etymology	Etymology: belonging to Gallia, a province of the Roman Empire largely coincident with modern France and the area where most findings of the new species were made.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFA8FFFEFF4BF9A54D8EFBB6.taxon	materials_examined	Type material. Holotype worker labelled “ FRA: 47.16846, 0.25379, 75 m, Chapelle Sainte Radegonde, swarming, Gouraud 2021.07.10 - 4 ”, “ Holotype Monomorium gallicum Seifert ”; 5 worker paratypes and 2 wingless gyne paratypes on two separate pins from the holotype nest with same collecting data but “ Paratypes Monomorium gallicum Seifert ”; all this material deposited in SMN Görlitz. All material examined. Morphometrically investigated were 23 nest samples with 73 workers and 10 gynes. They came from France (21 samples) and Germany (2 samples). For details see supplementary information SI 1, SI 2, SI 3. Geographic range and supposed origin. The vouchers from France concentrate to a zone of some 70000 km ² in SW France influenced by Atlantic climate from sea level to 168 m, with border points Ile-d’Yeu in the northwest (46.69 ° N, 2.28 ° W), Chapelle Sainte Radegonde in the northeast (47.17 ° N, 0.25 ° E), La Roque-Gageac in the east (44.83 ° N, 1.19 ° E] and Samatan in the south (43.49 ° N, 0.93 ° E). The two introduced supercolonial populations in urban regions around Mannheim in SW Germany are 42 km apart. The species was not found in the investigat- ed Nearctic material and should be of European or at least Old World origin. Assuming an autochthonous European origin appears somewhat problematic. Bernard (1968) described the presence of an ant that he called Monomorium minutum Mayr 1855 for West Europe and the whole Mediterranean. Unable to separate Monomorium monomorium, M. carbonarium and M. gallicum n. sp., it appears likely that he collected two or three species under this name. However, it is strange that he did not report any observation suggesting supercoloniality. Supercolonies should also not have escaped the attention of other 20 th century myrmecologists such as C. Collingwood but there are no reports for this. Monomorium gallicum n. sp. was either not present in Europe in that time or its colonies remained unobtrusive for most of their evolutionary history and developed a supercolonial demography only recently. The latter idea is not far-fetched as very recent occurrence of supercolonies in urban environments is documented for example in Plagiolepis pygmaea (Latreille 1798) from France (Charrier et al. 2020) as well as Switzerland and Germany in 2019 and 2021 (my own unpublished data).	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFA8FFFEFF4BF9A54D8EFBB6.taxon	diagnosis	Diagnosis: -- Worker (Tab. 3; Figs. 23, 24; key). Rather small, CS 480 ± 18 µm. Head longer than in M. carbonarium, CL / CW 1.242 ± 0.023. Dents on clypeal margin moderately long (ExCly / CS 4.42 ± 0.54 %), not very acute and moderately distant (ClSpD / CS 11.48 ± 0.79 %). Frontal carinae moderately distant and slightly diverging frontad (FL / CS 0.286 ± 0.007, FR / CS 0.276 ± 0.007, FL / FR 1.036 ± 0.020). Eye rather small and preocular distance moderately large (EL / CS 0.199 ± 0.005, PrOc / CS 0.229 ± 0.007). Scape and funiculus segments rather long, 3 rd funiculus segment significantly longer than in M. carbonarium (SL / CS 0.824 ± 0.012, Fu 2 / CS 6.74 ± 0.30 %, Fu 3 / CS 5.35 ± 0.22 %). Mesosoma slightly longer than in M. carbonarium and rather narrow (ML / CS 1.204 ± 0.027, MW / CS 0.571 ± 0.010). Metanotal groove moderately deep, MGr / CS 4.94 ± 0.62 %. Dorsum and slope of propodeum in profile forming a convex, suggestedly angulate curve. Petiole rather wide and high but moderately long (PeW / CS 0.293 ± 0.012, PeH / CS 0.380 ± 0.010, PeL / CS 0.438 ± 0.014). Postpetiole rather wide and higher than in M. carbonarium (PpW / CS 0.328 ± 0.012, PpH / CS 0.306 ± 0.008). All body surfaces with exception of few rugulae on frontal lobes, ventral mesopleuron, ventrolateral area of metapleuron and genae glabrous and shiny. All body parts homogenously dark brown to jet black; mandibles, lateral clypeus and antennal funiculus lighter brown. -- Gyne (Tab. 5): Only wingless gynes are known so far. Most individuals are morphometrically separable from wingless gynes of M. carbonarium in a PCA (Fig. 7). Perhaps it is also possible to separate them from the latter species by the steeper slope of frontal petiole profile. Taxonomic comments. The very clear separation of worker samples from M. carbonarium and M. ergatogyna has been demonstrated above (Figs. 31, 33; Tab. 1).	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFA8FFFEFF4BF9A54D8EFBB6.taxon	biology_ecology	Biology. (synthesis of information from C. Gouraud, B. Kaufmann, C. Galkowski, G. Heller pers. comm.). Coastal habitats in France include white and grey dunes, edge of dune groves with maritime pines and holm oaks, cliffs, dry grasslands and road sides. In rural and urban habitats it is found in gardens and parks and once in a greenhouse with Begonia. Occurrence in fully sealed urban habitats such as parking grounds or streets was repeatedly reported and is possible if there is some greenery (trees, flower beds etc.) nearby. Nests are under stones, in dead wood, fence posts and old stone walls. The species is frost resistant: the colony in Weinheim survived the cold winters 2009 / 2010 and 2011 / 12. It is very polygynous and may dominate a site where it coexists with Lasius psammophilus, Formica cf. selysi in dune environment and is also able to establish in dune sites colonized by species of the Tapinoma nigerrimum group. Competing ant species are very effectively repelled by gaster-flagging during which an irritating poison gland secretion is released from the extruded sting. Very populous supercolonies were observed in four localities in urban environments. The supercolony in Weinheim became a nuisance in houses and caused damage to electronic installations. On smooth ground the foraging radius may extend more than ten meters. Trophobiotic organisms on bushes and trees such as aphids and scale insects may be visited by huge files of workers. It is extremely polyphagous using nectar and pollen, dead invertebrates, diverse foodstuffs in households and was seen to re- trieve small seeds with elaiosomes. Large arthropods are disintegrated by numerous workers at the site after having repelled competitors. There is one observation of swarming 10 July 2021 from France when the wingless gynes climbed on grasses, branches or other elevated points at the periphery of the nest (SaNo 50). Such behavior makes only sense in order to better attract flying males of other colonies by sex pheromones. This observation corresponds to the case reported above for wingless gynes of Monomorium carbonarium. It remains to be investigated if winged gynes are really absent in this species. Monomorium ebeninum Forel 1891	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAEFFFFFF4BFB3A4DCFFE7B.taxon	description	The species has been described from the Caribbean islands St. Vincent and St. Thomas. Investigated were the lectotype gyne labelled “ Typus ”, “ Monomorium minutum Mayr r. ebeninum Forel St. Vincent ”, “ Monomorium ebeninum Forel Lectotype M. DuBois 1983 ”, “ ANTWEB CASENT 0908695 ”; 9 paratype workers labelled “ Typus ”, “ ebeninum Forel ”, “ Monomorium St. Thomas (Antille) 14 X 78 ”, “ ANTWEB CASENT 0908696 ”; all material deposited in MHN Genève.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAEFFFFFF4BFB3A4DCFFE7B.taxon	materials_examined	All material examined. Numeric phenotypical data were taken in the lectotype gyne from St. Vincent and 4 worker samples with 9 individuals from St. Thomas and Barbados. For details see supplementary information SI 1, SI 2, SI 3. Geographic range. Probably entire Caribbean and, so far, not reliably confirmed from outside this region. Images in www. antweb. org (CASENT 0729633, CASENT 0318457) showing worker specimens from the Grenadines can be referred to this species. DuBois (1986) reported the species from over 40 localities in the Caribbean and Middle America but it is unclear how he could determine these samples based on the useless characters given in his key and species description.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAEFFFFFF4BFB3A4DCFFE7B.taxon	diagnosis	Diagnosis: -- Worker (Tab. 2, Figs. 1, 12, key). Very small, CS 445 µm. Head longer than in most species of the group, CL / CW 1.263 ± 0.025. Dents on clypeal margin rather short (ExCly / CS 3.11 ± 0.49 %), not very acute and moderately distant (ClSpD / CS 10.36 ± 1.26 %). Frontal carinae more approached (FR / CS 0.244 ± 0.006) and more diverging frontad than in related species (FL / CS 0.268 ± 0.006, FL / FR 1.099 ± 0.021). Eye and preocular distance moderately large (EL / CS 0.206 ± 0.009, PrOc / CS 0.231 ± 0.003). Scape and funiculus segments moderately long (SL / CS 0.834 ± 0.011, Fu 2 / CS 6.47 ± 0.37 %, Fu 3 / CS 5.07 ± 0.11 %). Mesosoma moderately long and wide (ML / CS 1.230 ± 0.028, MW / CS 0.566 ± 0.007). Metanotal groove very deep, MGr / CS 7.20 ± 0.68 %. Propodeum edged, its dorsal profile and posterior slope rather straight and forming a blunt angle of ± 130 ° (Fig. 12). Petiole rather wide and high (PeW / CS 0.289 ± 0.015, PeH / CS 0.377 ± 0.008). Postpetiole wide and rather high (PpW / CS 0.356 ± 0.009, PpH / CS 0.289 ± 0.017). All body surfaces with exception of few rugulae on frontal lobes, ventrolateral area of metapleuron and genae glabrous and shiny. All body parts homogenously dark brown to jet black. -- Gyne (Tab. 5; Figs. 27, 28): According to the morphometric data of the lectotype gyne given in Tab. 5, there is hope that this species could be well separable in this caste as a combination of small FR / CS, MW / CS, MH / CS and large EL / CS as well as by the overall shape. Taxonomic comments. The lectotype is in a PCA well separated from all other wingless gynes (Figs. 5, 6). Based on the characters underlined in the description above, the worker is comparably easy to determine. With all measurements in mm, a discriminant 152.22 * FR- 206.87 * MGr- 113.08 * ExCly- 69.2 * PpW / CS- 3.0 <0 separates the nine available Monomorium ebeninum specimens fully from the 390 workers of all other species of the M. carbonarium group.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAEFFFFFF4BFB3A4DCFFE7B.taxon	biology_ecology	Biology. Wheeler (1905) reported nesting under stones, in cavities of Tillandsia species and dry twigs of buttonwood bushes with up to 12 queens per nest. According to Smith (1936) its colonies are populous and polygynous with the nests found in both soil and wood, back of the leaf sheaths of corn and bananas, in cabbage heads, Tillandsia plants and in Hibiscus sabdariffa fruits. The same author reported exceeding trophobiosis with scale insects and aphids and strong predatory activity. According to Wolcott & Martorell (1937) it predates on eggs of the sugarcane moth borer Diatraea saccharalis Fabricius. Males were observed in Jamaica 14 March 1911 and in the Bahama Islands 31 May 1904 (DuBois 1986). The species is assumed to have only wingless gynes (S. Cover pers. comm.). Monomorium marjoriae DuBois 1986	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAFFFFFFF63FE684A26FDC6.taxon	description	The species has been described by a single nest sample from Mexico: Nayarit: Puga (DuBois wrote “ Punga ” – obviously a misspelling). These types were not available but this taxon shows exceptionally clear characters to allow an identification even by the rough description of DuBois (1986).	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAFFFFFFF63FE684A26FDC6.taxon	materials_examined	All material examined. Numeric phenotypical data were taken in two samples with 8 workers from Tepic and Santiago Ixcuintla in Mexico. For details see supplementary information SI 1, SI 2. Geographic range. The three known sites in Mexico – Puga (21.58 ° N, 104.82 ° W, 700 m), Tepic (21.50 ° N, 104.89 ° W, 937 m) and Santiago Ixcuintla (21.81 ° N, 105.21 ° W, 17 m) – are situated in the Province Nayarit.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAFFFFFFF63FE684A26FDC6.taxon	diagnosis	Diagnosis: -- Worker (Tab. 2, Figs. 13 - 15, key). Comparatively large, CS 504 ± 11 µm. Head moderately long, CL / CW 1.226 ± 0.024. Dents on clypeal margin short (ExCly / CS 2.53 ± 0.40 %), not very acute and moderately distant (ClSpD / CS 9.31 ± 0.46 %). Frontal carinae moderately approached (FR / CS 0.266 ± 0.009) and only weakly diverging frontad (FL / CS 0.274 ± 0.010, FL / FR 1.033 ± 0.024). Eye smaller and preocular distance larger than in other species (EL / CS 0.187 ± 0.004, PrOc / CS 0.252 ± 0.004). Scape and funiculus segments much longer than in most other species (SL / CS 0.887 ± 0.006, Fu 2 / CS 6.67 ± 0.28 %, Fu 3 / CS 5.53 ± 0.09 %). Mesosoma more slen- der than in all other species (ML / CS 1.270 ± 0.013, MW / CS 0.536 ± 0.006). Metanotal groove rather deep, MGr / CS 5.41 ± 0.64 %. Dorsal profile and posterior slope of propodeum straight and forming a distinct angle of 130 ° with a clear corner (Fig. 14). Waist segments moderately high and wide (PeW / CS 0.280 ± 0.016, PeH / CS 0.372 ± 0.007, PpW / CS 0.329 ± 0.013, PpH / CS 0.290 ± 0.005). All body surfaces rather smooth, with exception of few rugulae on frontal lobes, ventrolateral area of meso- and metapleuron and genae. Lighter colored than other species: Head brown to dark brown, mesosoma yellowish-brown to brown, gaster brown to dark brown, mandibles yellowish-brown. -- Gyne: unknown Taxonomic comments. Based on the characters underlined in the above description, the worker is comparably easy to determine and clearly separated as distinct cluster by explorative data analyses. The second and third component of a principal component analysis considering all 19 characters placed the M. marjoriae as well as those of M. monomorium and M. lorenzoi n. sp. widely separate from the samples of the seven remaining species of the M. carbonarium species complex (Fig. 36).	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAFFFFFFF63FE684A26FDC6.taxon	biology_ecology	Biology. Unknown. Monomorium viridum Brown 1943	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAFFFFCFCE6FD8A4DD7F965.taxon	description	This species has been described on males, gynes and workers from Lakehurst in New Jersey. Investigated were a paratype winged gyne labelled: ” Paratype Monomorium viridum Brown ” [hand-written by Brown], “ Lakehurst VIII- 25 - 40 N. J. W. L. Brown ” and “ USNM paratype No 58070 ” and series of five workers labelled “ Paratype Monomorium viridum Brown ” [hand-written by Brown], “ Lakehurst VI- 14 - 42 N. J. W. L. Brown ”, “ USNM paratype No 58070 ” and “ CASENT 0105770 ANTWEB ”; both series deposited in NMNH Washington.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAFFFFCFCE6FD8A4DD7F965.taxon	description	This taxon has been described from Florida: Dade Co., South Miami based on gynes and workers. Investigat- ed were three paratype winged gynes and nine workers on four pins from NMNH Washington all labelled “ So. Miami Fla VII- 8 - 41 EV Gregg ” “ Crater in sandy soil pine palmetto ”, “ Paratype No. 57281 U. S. N. M. ” I confirm the synonymy stated by DuBois (1986). The type workers of M. penisulatum as well as another work- er sample from Florida do not show any differences to the material of M. viridum from more northern latitudes. The smaller head size and larger ClSpD of the southern population are within the normal range of intraspecific variation known for the M. carbonarium species group.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAFFFFCFCE6FD8A4DD7F965.taxon	materials_examined	All material examined. Numeric phenotypical data were taken in 5 samples with 15 workers and 8 winged gynes. For details see supplementary information SI 1, SI 2, SI 3. All this material originated from the eastern states of the USA Geographic range. Only known from lowland areas of the eastern states of USA: New York (40.79 ° N, 74.31 ° W), New Jersey, North Carolina and Florida (25.76 ° N, 80.19 ° W) from sea level up to 23 m.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAFFFFCFCE6FD8A4DD7F965.taxon	diagnosis	Diagnosis: -- Worker (Tab. 2, Figs. 16 - 18, key). Very small, CS 460 ± 22 µm. Head much shorter than in most species of the group, CL / CW 1.147 ± 0.015. Dents on clypeal margin rather long (ExCly / CS 5.67 ± 0.99 %), very acute and widely distant (Fig. 18, ClSpD / CS 12.68 ± 0.97 %). Frontal car inae more diverging frontad than in most other species (FL / FR 1.077 ± 0.46, FL / CS 0.286 ± 0.007, FR / CS 0.266 ± 0.012). Eye and preocular distance moderately large (EL / CS 0.210 ± 0.007, PrOc / CS 0.240 ± 0.009). Scape and funiculus segments very long (SL / CS 0.861 ± 0.014, Fu 2 / CS 6.86 ± 0.43 %, Fu 3 / CS 5.27 ± 0.24 %). Mesosoma moderately long and wide (ML / CS 1.218 ± 0.019, MW / CS 0.582 ± 0.013). Metanotal groove deep, MGr / CS 6.07 ± 0.93 %. Dorsal and caudal profile of propodeum not meeting in an angle, as a whole more or less convex. Petiole moderately wide but higher than in most other species (PeW / CS 0.285 ± 0.012, PeH / CS 0.394 ± 0.011). Postpetiole moderately wide but higher than in other species (PpW / CS 0.356 ± 0.009, PpH / CS 0.315 ± 0.009). Lateral area of mesopleuron dorsad to metanotal groove strongly longitudinally rugulose. Head, mesosoma and gaster dark brown to brown; mandibles antennae and lateral margin of clypeus yellow brown. According to DuBois (1986) the occipital region of head and the dorsum of mesosoma show a green tint in living or freshly dead individuals. -- Gyne (Tab. 4): The winged gyne should be easily recognized by its low head length index (CL / CW 0.941 ± 0.022) and very large diameter of midocellus (OD / CS 0.133 ± 0.012). A wingless gyne was not available but the data of DuBois (1986) suggest that these have a lower head length index than wingless gynes of other species. Taxonomic comments. The species is comparably easy to recognize as a combination of the characters underlined above.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFAFFFFCFCE6FD8A4DD7F965.taxon	biology_ecology	Biology. It seems that DuBois (1986) could reliably identify this species and I follow here his statements on live history: The main habitat are open areas with sandy soil. Nest entrances may be marked by craters of ejected sand having a diameter of 12 - 20 cm. Nest populations are polygynous usually having up to five (rarely up to 60) reproductive gynes. Alates have been observed in July. The morphology of winged gynes indicates a potency for f light-dispersal and independent colony foundation. Wingless gynes were observed in two localities. Monomorium emarginatum DuBois 1986	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFACFFFDFF4BF96A4A7DFCCD.taxon	materials_examined	This species has been described on males, gynes and workers from near Amissville in Virginia. Investigated were the holotype winged gyne labelled “ 2 mi w Amissville Rappahannock Co. ”, VIGINIA June 21, 1957 W. L. Brown E. O. Wilson ”, “ M. C. Z. Holotype 32922 ”, “ Monomorium emarginatum Holotype M. DuBois 1983 ”; One paratype winged gyne and 3 paratype workers on the same pin labelled “ Brewster C. Cod P. rig. and oak on sand ”, “ Mass. VIII. 4. 1955 W. L. Brown ”, “ M. C. Z. Paratype 32922 ”, “ Monomorium emarginatum Paratype M. DuBois 1983 ”; depository MCZ Cambridge. All material examined. Numeric phenotypical data were taken in 9 samples with 30 workers and three winged gynes. For details see supplementary information SI 1, SI 2, SI 3. All this material originated from the USA. Geographic range. Apparently widely distributed in the USA. Vouchers are from the states New York, Pennsylvania, Maine, Massachusetts, Maryland, Virginia, North Dakota, Utah and New Mexico from sea level up to 2044 m in New Mexico.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFACFFFDFF4BF96A4A7DFCCD.taxon	diagnosis	Diagnosis: -- Worker (Tab. 2, Figs. 19 - 20, key). Very small, CS 460 ± 25 µm. Head rather short, CL / CW 1.180 ± 0.026. Dents on clypeal margin moderately long (ExCly / CS 4.20 ± 0.75 %), not very acute and rather widely distant (ClSpD / CS 9.99 ± 0.93 %). Frons moderately wide and frontal carinae only very slightly diverging frontad (FL / FR 1.039 ± 0.24, FL / CS 0.269 ± 0.008, FR / CS 0.259 ± 0.009). Eye large and preocular distance moderately large (EL / CS 0.217 ± 0.008, PrOc / CS 0.223 ± 0.009). Scape and 3 rd funiculus segment very short (SL / CS 0.757 ± 0.014, Fu 2 / CS 5.67 ± 0.27 %, Fu 3 / CS 4.22 ± 0.29 %). Mesosoma relatively short and relatively wide (ML / CS 1.181 ± 0.035, MW / CS 0.583 ± 0.015). Metanotal groove moderately deep, MGr / CS 4.49 ± 0.74 %. Dorsal and caudal profile of propodeum not meeting in an angle, as a whole more or less convex. Petiole narrow, short and low (PeW / CS 0.267 ± 0.014, PeL / CS 0.406 ± 0.015, PeH / CS 0.344 ± 0.011). Postpetiole moderately wide but very low (PpW / CS 0.296 ± 0.013, PpH / CS 0.260 ± 0.010). Lateral area of mesopleuron smooth. Head, mesosoma and gaster dark brown to brown; mandibles and lateral clypeus yellow brown. -- Gyne (Tab. 4): Only winged gynes are known. Rath- er large (CS 807 ± 15 µm). Very short head, scape and petiole (CL / CW 0.978 ± 0.021, SL / CS 0.704 ± 0.021, PEL / CS 0.613 ± 0.015). The short median furrow on posterior mesonotum, called diagnostic by DuBois (1986), is occasionally also found in other species. Taxonomic comments. The worker is comparatively easy to recognize as a combination of the characters underlined above. With all measurements given in mm, the three gynes are separable from the 24 winged gynes of other species by the discriminant 48.34 * SL + 34.27 * PpW- 35.905 * CW- 4.336 PeL- 12.723 <0.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFACFFFDFF4BF96A4A7DFCCD.taxon	biology_ecology	Biology. Largely unknown. Alate winged gynes were observed in the nests 21 June 1957 (Amissville), 3 August 2000 (Androscoggin), 4 August 1955 (Cape Cod). The colony from Androscoggin / Maine was found as a “ crater nest in fine sand on an open spot with sparse vegetation within a Bracken Wintergreen stand ” (S. Cov- er). The workers from Green Canyon / Utah were found “ on blossoming Cirsium lanceolatum ” (G. F. Knowlton). Monomorium lorenzoi n. sp.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFACFFFDFF4BF96A4A7DFCCD.taxon	etymology	Etymology: dedicated to the collector Lorenzo Fraysse. Type material. Holotype plus two paratype workers on the same pin labelled “ USA: 32.83908, - 117.04528, 85 m Mission Trail Park, sandy river bank, riparian vegetation, L. Fraysse 2024.03.22 - 3569 ” All material examined. Only the type sample was available. For details see supplementary information SI 1, SI 2. Geographic range. Only the type locality is known.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFACFFFDFF4BF96A4A7DFCCD.taxon	description	Description: -- Worker (Tab. 2, Figs. 27, 28, key). Very small, CS 454 ± 5 µm. Head elongated, CL / CW 1.248 ± 0.014. Dents on clypeal margin moderately long (ExCly / CS 4.08 ± 0.17 %), not very acute and widely distant (ClSpD / CS 11.03 ± 0.66 %). Frons very narrow and frontal carinae only very slightly diverging frontad (FL / FR 1.028 ± 0.25, FL / CS 0.247 ± 0.009, FR / CS 0.240 ± 0.008). Eye larger than in other species and preocular distance moderately large (EL / CS 0.225 ± 0.005, PrOc / CS 0.214 ± 0.003). Scape and 3 rd funiculus segment long (SL / CS 0.843 ± 0.012, Fu 2 / CS 6.35 ± 0.37 %, Fu 3 / CS 5.27 ± 0.21 %). Mesosoma moderately long but very narrow (ML / CS 1.186 ± 0.009, MW / CS 0.537 ± 0.002). Metanotal groove moderately deep, MGr / CS 4.80 ± 0.35 %. Dorsal and caudal profile of propodeum forming an angle of 140 °. Petiole narrow, extremely short and very low (PeW / CS 0.265 ± 0.012, PeL / CS 0.386 ± 0.003, PeH / CS 0.334 ± 0.008). Postpetiole moderately wide and low (PpW / CS 0.306 ± 0.011, PpH / CS 0.272 ± 0.015). All surfaces of head, mesosoma and gaster glabrous with exception few longitudinal carinulae on lateral parts of frontal lobes, lateral parts of clypeus, ventrolateral metapleuron and caudolateral mesopleuron (continuing dorsad into the metanotal groove). Head, mesosoma and gaster black; mandibles and lateral clypeus yellow brown. -- Gyne: unknown. Taxonomic comments. The combination of the characters underlined above is diagnostic. The description of a new species based on a single nest sample appears justified because of all three specimens represent a combination of extreme character expressions. A simple index of three shape variables FL / CS * PeL / CS / (EL / CS) is 0.425 ± 0.004 [0.422, 0.430] in the types of M. lorenzoi n. sp. but 0.604 ± 0.052 [0.449,0.765] in 400 specimens of all other species. The hypothesis that the type sample of M. lorenzoi n. sp. could represent nothing but a simple monogenous mutant of the abundant species M. ergatogyna appears unlikely because the three shape variables, representing different body parts, are not cor- related in 83 workers of the latter species. The mean Pearson’s correlation coefficient between the three variables is in M. ergatogyna 0.089 ± 0.033 – for comparison this coefficient is in the same sample 0.752 between PeW / CS and PpW / CS, 0.696 between FL / CS and FR / CS or 0.601 between Fu 2 / CS and Fu 3 / CS.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFACFFFDFF4BF96A4A7DFCCD.taxon	biology_ecology	Biology. The few specimens were collected foraging on very low vegetation immediately around the nest entrance. The latter was a very small hole in the ground (<1 mm of diameter) without any soil ejections around, in thin but very compacted ferruginous sand (on a welltrodden path). The micro-habitat was the path delimiting a low riparian vegetation from a drier grassland. Monomorium monomorium Bolton 1987	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFADFFF2FCE4FCF14CADFAB3.taxon	description	Replacement name for Monomorium minutum Mayr 1855 [junior secondary homonym of Atta minuta Jerdon 1851]. This species has been described under the name Monomorium minutum from Italy. Mayr (1855: 453) gave three type localities “ Lombardie (Villa) ... Insel Lido bei Venedig (Strobel) ... im Kirchenstaate bei Imola (Pirazzoli) ”. Investigated were 1 syntype worker labelled “ Venedig Lido Coll. G. Mayr ”, “ zu Zool. bot. Gesell Wien Bd. V. p. 273 “, „ Monomor. minutum det. G. Mayr “, “ Type “; 1 syntype worker labelled “ Lido, Strobl “, “ minutum G. Mayr Type ”, “ TYPUS ”, “ ANTWEB CASENT 091600 ”; depository of both samples NHM Wien.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFADFFF2FCE4FCF14CADFAB3.taxon	discussion	Comment. The text of the description of Atta minuta Jerdon 1851 is as follows: “ Worker barely 1 / 12 th of an inch long (= 2 mm B. S.), head oblong, eyes minute, advanced; thorax narrow; abdominal pedicles long, narrow, the first much more raised than the second; antennae gradually thickening, of a rufous color with the abdomen somewhat darker of fuscous. Female about 1 / 3 of an inch long (= 8 mm!, B. S.), similar in form to the worker, abdomen larger proportionally, and head small- er ... makes a temporary nest in various situations, in an empty box, between the back of a book and its leaves, even among the loose pages of a book, in an empty shell ... Nothing is used in its construction ... ” This original description does not give any drawing of the ants and makes genus or species identification questionable. The conclusion of Bolton (1987) that Atta minuta Jerdon belongs to the genus Monomorium and that it is a junior synonym of Monomorium pharaonis (Linnaeus 1758) is speculative. The reported total length of the gyne of 8 mm speaks against this. Dry mounted gynes of M. pharaonis have a total length of 4 to 5 mm and even living, physogastric gynes will never be longer than 6 mm. Anyway, I do not perform here a name reversal by depositing Atta minuta under Incertae Sedis and maintain the current use. All material examined. Numeric phenotypical data were taken in 11 samples with 29 workers. The material originated from France (4 samples), Greece (1), Italy (1), Netherlands (1) and Spain (4). For details see supplementary information SI 1, SI 2. Geographic range. The unclear species separation of the tiny blackish Monomorium in the past led to controversial interpretations if this species is of Europe- an origin or introduced here (see Gómez et al. 2024). I have strong doubts that M. monomorium can be considered as a true tramp species with cosmopolitan distribution since the separation from similar Orientalic or Polynesian-Australasian species was so far not clear. This refers in particular to species or populations related to or conspecific with Monomorium liliuokalanii Forel 1899 (see statements in the diagnosis of the M. carbonarium group above). As long as no counterevidence is presented, I consider Monomorium monomorium as truly West Palaearctic-Mediterranean and as a strongly under-recorded species. All available samples are from elevations below 150 m a. s. l. in Spain, S France, Italy and Greece. The finding in the Netherlands is an introduction with plant material.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFADFFF2FCE4FCF14CADFAB3.taxon	diagnosis	Diagnosis: -- Worker (Tab. 2, Figs. 8 – 10, key). Smallest species of the M. carbonarium group, CS 407 ± 17 µm. Head rather short, CL / CW 1.179 ± 0.028. Clypeal spines reduced to short, blunt, often two-cusped dents (Fig. 10); as result median clypeal excision extremely shallow, ExCly / CS 1.71 ± 0.44 %, ExCly 7.0 ± 1.8 µm. Frons wide and frontal carinae only very slightly diverging frontad (FL / FR 1.043 ± 0.21, FL / CS 0.294 ± 0.008, FR / CS 0.282 ± 0.006). Eye small and preocular distance moderately large (EL / CS 0.183 ± 0.006, PrOc / CS 0.221 ± 0.010). Scape and 2 nd funiculus segment very short (SL / CS 0.742 ± 0.012, Fu 2 / CS 4.82 ± 0.39 %, Fu 3 / CS 3.70 ± 0.29 %). Mesosoma relatively short and moderately wide (ML / CS 1.188 ± 0.026, MW / CS 0.577 ± 0.011). Metanotal groove rather shallow, MGr / CS 3.72 ± 0.87 %. Dorsal and caudal profile of propodeum forming a continuous convexity (Fig. 9). Petiole moderately wide, long and high (PeW / CS 0.276 ± 0.017, PeL / CS 0.428 ± 0.010, PeH / CS 0.362 ± 0.012). Postpetiole moderately wide and high (PpW / CS 0.313 ± 0.016, PpH / CS 0.282 ± 0.010). Dorsal surface of head glabrous with exception of longitudinal carinulae or rugulae on lateral clypeus. Contact area of mesopleuron and mesonotum with metapleuron and propodeum from ventral margin up to metanotal groove longitudinally carinulate or microrugulose. Head, mesosoma and gaster medium to dark brown. -- Gyne (Tab. 5): The two available wingless gynes are similar to winged gynes by their high and rather long mesosoma. However, the mesosomal sclerites necessary for wing movements are fused and there are no remains of shed wings detectable. Hence these gynes are classified as wingless gynes which is also confirmed by a PCA (Fig. 5). They are separable from other wingless gynes of the species group alone by the ratio SL / MH that is 0.658 and 0.706 in M. monomorium whereas it is> 0.760 in all known wingless gynes of the other species. Taxonomic comments. If there is no unknown cryptic diversity, M. monomorium should be safely determinable considering the characters underlined above or given in the key.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
03C887CFFFADFFF2FCE4FCF14CADFAB3.taxon	biology_ecology	Biology. (according to Emery 1916, Wagner et al. 2018, Gomez et al. 2024, M. Mei pers. comm., F. Rigato pers. comm., J. Reyez-Lopez pers. comm., A. Scupola pers. comm.): Nest populations are rather small and weakly polygynous. Supercolonies or occurrence as pest species have never been observed. The nests are easily overlooked due to small forager populations, minute size, rather slow movements and a tiny entrance hole of less than 1 mm width without any soil ejections surrounding it. It was observed to tend honeydew-producing insects on citrus trees. Among 11 sampling spots with habitat data, 6 were on alluvial, sandy soils close to sea and 3 on sandy lagoon soils at the Mediterranean Sea. The habitats are open or light stands of trees and shrub, often natural or semi-natural, but also a camping place, an urban park, an archeological site and a garden center in the Netherlands.	en	Seifert, Bernhard (2025): The Monomorium carbonarium species group in the Nearctic and Europe (Hymenoptera: Formicidae). Soil Organisms (Toronto, Ont.) 97 (1): 55-84, DOI: 10.25674/441, URL: http://dx.doi.org/10.25674/441
