Cardiocondyla, Emery, 1869

Seifert, Bernhard, 2023, A revision of the Palaearctic species of the ant genus Cardiocondyla Emery 1869 (Hymenoptera: Formicidae), Zootaxa 5274 (1), pp. 1-64 : 8-11

publication ID

https://doi.org/ 10.11646/zootaxa.5274.1.1

publication LSID

lsid:zoobank.org:pub:F60E9DF7-6E56-449E-B6D8-4069D4F9D1D0

DOI

https://doi.org/10.5281/zenodo.7893229

persistent identifier

https://treatment.plazi.org/id/F8463F14-4079-9C55-FF19-615CFA14AD97

treatment provided by

Plazi

scientific name

Cardiocondyla
status

 

Key to the species View in CoL View at ENA with outdoor occurrence in the Palaearctic

In order to comprise all 34 species with outdoor occurrence in the Palaearctic, the key and the supplementary information SI1 and SI2 additionally included nine species of species groups with other zoogeographic origin. These species either extend their range into the southern Palaearctic or are globally dispersing tramp species potentially occurring in each locality with sufficiently warm climate. The complete taxonomic names of these added species are Cardiocondyla minutior Forel 1899 , C. tjibodana Karavajev 1935 and C. goa Seifert 2003 (all three belonging to the C. minutior species group), C. emeryi Forel 1881 (belonging to the C. emeryi species group), C. fajumensis Forel 1913 and C. unicalis Seifert 2003 (both belonging to the C. shuckardi species group), C. wroughtonii (Forel 1890) and C. obscurior Wheeler 1929 (both belonging to the C. wroughtonii species group) and C. mauritanica Forel 1890 (belonging to the C. nuda species group).

The key presented below almost thoroughly used dichotomous decision schedules for cases requiring combinations of multiple characters and in the same time it aspired to achieve a low error rate inevitably resulting in tedious procedures. Lamenting does not help here and those who think that simple answers can be given for difficult problems bark up the wrong tree. The finally best approach is here using a software providing linear discriminant functions (LDA), measuring the full set of morphometric characters and running the investigated samples as wild-cards within the data space of the hypothesis-providing supplementary file SI2. It is convenient to run the analysis with primary (raw) measurements instead with ratios. A good check of the result is then comparing with the images that are given for any species in four aspects and to consider geographic distribution. The low error rates reported in the key cannot be achieved for such tiny ants without high-resolution optical systems, a good measuring stage and a careful realization of character definitions.

1a Anterior postpetiolar sternite laterally more prominent than in median part—as result an imagined cross section shows a deeply concave ventral margin of the sternite. The lateral protrusions appear in frontolateral view as dents ( Fig. 113 View FIGURES 109–113 ). C. wroughtonii View in CoL group............................................................................................... 2

1b Anterior postpetiolar sternite in median part more prominent or at equal level as the lateral surface—as result an imagined cross section shows a convex or straight ventral margin of the sternite................................................ 3

2a With all measurements in mm, discriminant 34.21* CW-59.33 *PoOc-177.83* EYE +72.15* SL-113.56 * FRS-106.46 *SP+140.69*PpW-14.15 <0 [error 0% in 37 nest sample means of two workers measured]. 1 st gaster segment in a majority of samples with absent or weakly developed blackish pigmentation. Worldwide tramp species. Outdoor occurrence confirmed for the Middle East. Figs. 105–108 View FIGURES 105–108 ...................................................... wroughtonii View in CoL

2b Discriminant> 0 [0% error in 65 nest sample means of two workers]. 1 st gaster segment in a majority of samples with strongly developed blackish pigmentation. Worldwide tramp species. Outdoor occurrence confirmed for southern Spain and the Middle East. Figs.109–113 View FIGURES 109–113 ............................................................................. obscurior

3a True foveolae on vertex dorsal of the eyes completely absent. Instead the bases of pubescence hairs are placed in the center of flat tubercles or flat pits of only 4–10 µm diameter, giving a finely punctate surface appearance at lower magnifications ( Figs. 89 View FIGURES 86–89 , 97 View FIGURES 94–97 ). Postocular distance large, PoOc/CL 0.416 –0.467. Frons usually very wide, FRS/CS> 0.288 (except C. tibetana , here 0.280 ± 0.006). Propodeal spines reduced to blunt dents. Metanotal depression deep. C. stambuloffii View in CoL group.............. 4

3b Bases of pubescence hairs on vertex dorsal of the eyes placed in the center of foveolae or cuticular meshes of> 10 µm diameter ( Figs. 9 View FIGURES 6–9 , 25 View FIGURES 22–25 , 117 View FIGURES 114–117 )—if foveolae reduced ( verdensis n. sp.), than PoOc/CL <0.394. Frons narrower, FRS/CS <0.288. Metanotal depression varying from nearly absent to deep. Propodeal spines variable......................................... 8

4a Eye larger, EYE/CS>0.235. Frons narrower, FRS/CS <0.295. Waist segments lower, PeH/CS <0.343, PpH/CS <0.283. Southern and northern margin of Tarim Basin. Figs. 101–104 View FIGURES101–104 ............................................ tibetana

4b EYE/CS <0.235, FRS/CS> 0.295, PeH/CS>0.343, PpH/CS <0.283............................................ 5

5a Posterior 40% of vertex surface completely smooth except for tiny pits of 4–5 µm around the bases of pubescence hairs just visible with high-resolution stereomicroscopy. Pubescence longer. With all measurements in mm, discriminant 334.68*PLG-45.456*CW+88.43*PoOc-66.63*EYE -3.60> 2.3. South Kazakhstan. Figs. 98–100 View FIGURES 98–100 ........................... gibbosa

5b Posterior part of vertex not completely smooth, at least with weak rugulae and small tubercles around the bases of pubescence hairs. Discriminant <2.3............................................................................... 6

6a Westpalaearctic, known range extending east to the western shores of Caspian Sea. With all measurements in mm, discriminant 44.95*CW+54.68*PoOc+31.14*SL-130.25*SPBA-79.81*PpW +40.84*PeH+90.89*PpH -28.33 <0.4 [0% error in 82 individuals]. Figs. 86–89 View FIGURES 86–89 ...................................................................... stambuloffii View in CoL

6b Central Palaearctic, known range extending from western coast of Caspian Sea east to Mongolia. Discriminant> 0.4 [0% error in 59 individuals]..................................................................................... 7

7a With all measurements in mm, discriminant 120.6*PoOc-29.53*SL+109.54*PeW-109.42*PeH-157.97*PLG-7.70 <0.7 [0% error in 37 individuals]. Figs. 94–97 View FIGURES 94–97 ............................................................ rolandi n. sp.

7b Discriminant> 0.7 [0% error in 22 individuals]. Figs. 90–93 View FIGURES 90–93 ......................................... koshewnikovi View in CoL

8a Propodeal spines reduced to obtusely angled corners ( Fig. 115 View FIGURES 114–117 ). Postpetiole rather narrow, PpW/CS <0.46, in dorsal view never suggestively hexagonal. With all measurements in mm, discriminant 48.06*PoOc+27.66*SL-56.96*PpW+119.07*MGr-13.79> 0 [error 0% in 17 individuals].......................................................................... 9

8b Propodeal spines not reduced to obtusely angled corners. If spines occasionally reduced to blunt corners, then EYE/CS> 0.221 and PpW/CS>0.450. Discriminant <0 [error 0% in 1140 individuals].......................................... 10

9a Head elongated CL/CW> 1.16 ( Fig. 114 View FIGURES 114–117 ). Dorsum of promesonotum and lateral pronotum with more developed microsculpture ( Figs. 115, 116 View FIGURES 114–117 ). Head sculpture stronger, foveolae with regular margin ( Fig. 117 View FIGURES 114–117 ). Egypt and Saudi Arabia.......................................................................................................... fajumensis

9b Head very short CL/CW <1.16 ( Fig. 114 View FIGURES 114–117 ). Dorsum of promesonotum and lateral pronotum nearly glabrous ( Figs. 119, 120 View FIGURES 118–121 ). Head sculpture weaker, foveolae sometimes with irregular margin ( Fig. 121 View FIGURES 118–121 ). Iran............................. unicalis

10a Frons very narrow, FRS/CS 0.196 —0.228 ( Fig. 122 View FIGURES 122–125 ), postpetiole with a bulging sternite and high ( Fig.123 View FIGURES 122–125 .), PpH/CS 0.306 –0.358. With all measurements in mm, discriminant 128.52*FRS+42.56*PeW-143.94*PpH+1.616 <0 [error 0% in 145 specimens]. Confirmed outdoor occurrence in S Iberia, N Africa and Middle East. Figs. 122–125 View FIGURES 122–125 .................. emeryi View in CoL

10b Frons wider and postpetiole without a strongly bulging sternite. Discriminant> 0 [error 0% in 863 specimens].......... 11

11a Small, CW <420 mm. Metanotal depression very weak or absent, spines well developed, postpetiole much lower than petiole and with a completely flat sternite ( Fig. 127 View FIGURES 126–128 ). Vertex with deeply impressed foveolae ( Fig.126 View FIGURES 126–128 ). All surfaces of head, mesosoma and waist matt ( Fig. 128 View FIGURES 126–128 ). Outdoor occurrence confirmed for Egypt and Saudi Arabia........... minutior , tjibodana View in CoL & goa These species are inseparable by single or few characters. It is recommeded to measure CL, CW, SL, EYE, FRS, SP, PpW, PeH, PpH and PLG and then running the test specimens as wild-cards in a LDA against the data given in supplementary information SI2. The total classification error in 210 worker individuals in SI2 is 2.4%. Users who refrain from doing this time consuming and challenging separation are recommended to name this collective cluster........................... minutior aggr.

11b Larger, CW> 420 mm. Minute specimens of C. mauritanica View in CoL may match the character combination of 11a but differ by shorter spines and a thinner petiolar peduncle (compare Figs. 127 View FIGURES 126–128 and 130 View FIGURES 129–132 )............................................ 12

12a Outlines of postpetiole in dorsal view approximately hexagonal ( Fig. 131 View FIGURES 129–132 ). Metanotal depression shallow (MGr/CS 2.14±0.52). Propodeal spines developed as short dents ( Fig. 130 View FIGURES 129–132 ). Gastral pubescence dense (sqPDG 3.72 ± 0.28). Postocular distance large (PoOc/CL 0.447 ± 0.008, Fig. 129 View FIGURES 129–132 ). Microsculpture on vertex strongly reticulate ( Fig. 132 View FIGURES 129–132 ). With MGr, PoOc and SP in mm and sqPDG in µm, discriminant 136.0*MGr-25.0*PoOc*73.99*SP+1.81*sqPDG-7.2322 <0 [error 0% in 151 specimens]. Mediterranean and South Temperate zone of the Palaearctic.......................................... mauritanica View in CoL .

12b Outlines of postpetiole in dorsal view not approximately hexagonal. Metanotal depression usually deeper, propodeal spines more developed, gastral pubescence often more dilute, postocular distance usually smaller. Microsculpture on vertex different. Discriminant> 0 [error 0.3% in 619 specimens]............................................................ 13

13a Postocular distance extremely small (PoOc/CL <0.340). Petiole height and postpetiole width very low. With all measurements in mm, discriminant 30.96*PoOc-38.98*CL+17.12*PeH+26.77*PpW+ 7.196 <0 [error in 4 specimens 0%]. Kuweit. Figs. 62–65 View FIGURES 62–65 ....................................................................................... opistopsis

13b Postocular distance larger (PoOc/CL 0.342 –0.469]. Petiole height and postpetiole width higher. Discriminant>0 [error 0% in 612 specimens]...................................................................................... 14

14a Head surface between inner eye margin and paramedian vertex strongly microrugulose ( Fig. 69 View FIGURES 66–69 ). Dorsal promesonotum longitudinally microrugulose ( Fig. 68 View FIGURES 66–69 ).All surfaces of head, mesosoma and petiole matt due to more developed microsculpture. Dorsal profile of mesonotum straight, contrasting the clearly convex dorsal profile of propodeum, metanotal depression feebly suggested ( Fig. 67 View FIGURES 66–69 ). With all measurements in mm, discriminant 95.88*EYE-164.99*MGr-12.035> 0. Yemen. Figs. 66–69 View FIGURES 66–69 ............................................................................................... rugulosa

14b Body surfaces less microrugulose, often shiny. Dorsal profile of mesosoma different. Discriminant <0................ 15

15a Microsculpture of head with irregular foveolar margins ( Fig. 73 View FIGURES 70–73 ). Additionally differing from members of the elegans View in CoL and ulianini group by larger eye (EYE/CS 0.265 –0.274] and from members of the batesii View in CoL group by longer tergite pubescence (PLG/ CS 6.84–6.94). Afghanistan. Figs. 70–73 View FIGURES 70–73 ............................................................ kushanica View in CoL

15b Foveolae on vertex not with irregular margins. Character combination different................................... 16

16a Foveolae on vertex extremely small (dFOV 7.0–9.1 µm). Tergite pubescence very dilute (sqPDG 5.88–5.92). Scape and head much elongated (SL/CS 0.854 –0.867, CL/CW 1.238 –1.256). All   GoogleMaps body surfaces very shiny. Island endemic of Cape Verde, Figs.82–85 View FIGURES 82–85 ............................................................................... verdense n. sp.

16b Foveolae much larger (dFOV 12–21 µm). Tergite pubescence often more dense. Scape and head usually shorter......... 17

17a With sqPDG in µm and all other measurements in mm, discriminant 201.57*PLG-0.32*sqPDG-40.86*CL-10.32*PoOc+70.74 *SL+23.72*SPBA-24.27*SP+26.48*PeW+12.96*PpW-73.42*PeH-8.61> 0 [error 0% in 177 individuals]. C. elegans View in CoL group................................................................................................... 18

17b Discriminant <0 [error 0% in 322 individuals]. C. batesii View in CoL & C. ulianini group.................................... 21

18a Occurring from Iberia accross S France to Italy. Contact zone with dalmatica in the border region of NE Italy and Slovenia. With all measurements in mm, discriminant 56.7*SP+156*PeW-61.9*PoOc-126.2*PeH-48.2*PpW+126.6*MGr+17.86>0 [error 0% in 81 two-specimen nest samples]. Figs. 6–9 View FIGURES 6–9 ................................................... elegans View in CoL

18b Occurring farther east. If found in NE Italy or Slovenia, discriminant <0........................................ 19

19a Combination of larger foveloar diameter on vertex, lower postpetiolar height, longer propodeal spines and higher pubescence distance on gaster tergites. With dFOV, sqPDG in µm and SP, PpH in mm, discriminant 1.623*sqPDG+0.718*dFOV+96.14*SP -62.63*PpH-15.233> 2 [error 0% in 13 specimens]. S Georgia, NE Turkey, Iran, Afghanistan. Figs. 18–21 View FIGURES 18–21 ...... brachyceps

19b Foveolar diameter smaller, postpetiolar height larger, spines shorter, pubescence distance smaller. Discriminant <2 [error 1.4% in 72 specimens]..................................................................................... 20

20a Bases of propodeal spines more approached, petiole narrower and higher, surface of propodeum glabrous, propodeal spines very acute, petiole high with a very steep anterior profile of the node. With all measurements in mm, discriminant 163.8*PeH- 29.1*PeW-134.63*SPBA-5.68>2 [error 0% in 6 specimens]. Asia Minor. Figs. 14–17 View FIGURES 14–17 ............... dalmaticoides n. sp.

20b Bases of propodeal spines more distant, petiole wider and lower, surface of propodeum less glabrous, propodeal spines less acute, petiole lower with a less steep anterior profile of the node. Discriminant <2 [error 0% in 59 specimens]. From N Italy across the whole Balkans, Cyprus and Asia Minor east to the Iran. Northern range border in Austria, Slovakia and Hungary at 48°N. Figs. 10–13 View FIGURES 10–13 .............................................................................. dalmatica

21a With all measurements in mm, discriminant 32.44*CW-103.36*CL+134.03*PoOc-44.05*EYE+23.08*SL-41.77*SPBA+48.21*PpW-0.135 <0 [error 0% in 98 individuals]. Species of the C. batesii View in CoL group..................... 22

21b Discriminant> 0 [error 0.4% in 241 individuals]. Species of the C. ulianini group................................. 25

22a Frontal carinae notably diverging frontad, FL/FR>1.109. Postocular distance large, PoOc/CL>0.408. Metanotal depression very shallow, MGr <2.5 %. Jordan. Figs. 74–77 View FIGURES 74–77 ...................................................... tenuifrons

22b Frontal carinae less diverging, FL/FR <1.110. Postocular distance smaller, PoOc/CL <0.409. Metanotal depression deeper, MGr usually> 2.5 %................................................................................. 23

23a Petiole massive, ratio PeW /PpW> 0.57. With all measurements in mm, discriminant 152.578*PeW-69.53*PpW+2.092*SL+3 0.63*PoOc-10.57> 2.5 [error 0% in 4 individuals]. Only known from two sites in Asia Minor. Figs. 58–61 View FIGURES 58–61 ....... semirubra

23b Petiole less massive, ratio PeW/PpW in 97% of individuals <0.57. Discriminant <2.5 [error 0% in 132 individuals. Figs. 54–57............................................................................................. 24 View FIGURES 54–57 View FIGURES 22–25

24a With all measurements in mm, discriminant 63.22*CL-63.18*PoOc+55.89*SL+64.64*PeW-184.93*PeH-93.82*PpH-11.19 <0 [error 0% in 37 specimens]. Morocco, Tunisia, Algeria, Spain. Figs. 54–57 View FIGURES 54–57 .................................. batesii View in CoL

24b Discriminant> 0 [error 0% in 95 specimens]. Portugal, Morocco, Algeria, Tunisia, Egypt, Cyprus, Turkey, Middle East, Iran eastwards to 56°E. Color polymorphic. Figs. 78–81 View FIGURES 78–81 ....................................................... nigra View in CoL

25a Frons very narrow, FRS/CS 0.225; propodeal spines acute but very short, SP/CS 0.071; postocular distance small, PoOc/CL 0.403; postpetiole wide PpW/CS 0.552. With all measurements in mm, discriminant 160.18*FRS+41.17*PoOc-45.99*PpW- 15.23 <0. Israel. Figs. 34–37 View FIGURES 34–37 ..................................................................... gallilaeica

25b Frons wider; propodeal spines longer; postocular distance larger; postpetiole often narrower. Discriminant> 0 [error 0% in 240 specimens]......................................................................................... 26

26a Combination of large propodeal spine base distance, small eye, large postocular distance, broad and high postpetiole. With all measurements in mm, discriminant 44.74*PoOc-167.14*EYE+161.96*SPBA-56.07*PpW+31.77*PpH+0.543>0 [error 0% in 179 specimens]...................................................................................... 27

26b Propodeal spine base distance smaller, eye larger, postocular distance smaller, postpetiole narrower and lower. Discriminant <0 [error 0% in 61 specimens]........................................................................... 29

27a With sqPDG in µm and all other measurements in mm, discriminant 163.54*PoOc+0.755*sqPDG-57.89* CL-58.26 *CW+197. 78* EYE +47.39* FRS-54.85 *SP+55.08*PeW-109.15*PeH+53.45*PpH-178.59* PLG-4.19 > 0.5 [error 0% in 84 specimens]. S Balkans and Asia Minor. Figs. 42–45 View FIGURES 42–45 ............................................................... bulgarica View in CoL

27b Discriminant <0.5 [error 0% in 95 specimens]............................................................. 28

28a Microsetae on clypeus shorter ( Fig. 46 View FIGURES 46–49 ), pubescence on all body parts shorter, foveolae on vertex less densely packed ( Fig.49 View FIGURES 46–49 ), postpetiole wider, petiole node in lateral view more symmetric ( Fig.47 View FIGURES 46–49 ), dorsum of mesosoma and waist shiny and mesosoma frequently darker. With dFOV in µm and all other measurements in mm, discriminant 0.965*dFOV+164.79*EYE-38.64*PpW+123.49* PLG +77.67*MGr-32.49 <0 [error 2.9% in 69 specimens]. SE Balkans, Asia Minor, Israel, Caucasus, Caspian region , Iran, Afghanistan, Kyrgistan. Figs, 46–49.............................................. sahlbergi View in CoL

28b Microsetae on clypeus longer ( Fig. 50 View FIGURES 50–53 ), pubescence on all body parts longer, foveolae on vertex more densely packed ( Fig. 53 View FIGURES 50–53 ), postpetiole narrower, petiole node in lateral view more asymmetric ( Fig. 51 View FIGURES 50–53 ), dorsum of mesosoma and waist less shiny and mesosoma frequently lighter. Discriminant> 0 [error 7.7% in 26 specimens]. Georgia, Iran. Figs 50–53 View FIGURES 50–53 ........... persiana

29a Vertex with rather large, well-demarcated, bicoronate and densely-packed foveolae and in anteromedian part with well-developed longitudinal sculpture( Figs. 38, 41 View FIGURES 38–41 ). Pubescence on gaster tergites more dense. With dFOV, sqPDG in µm and SPBA in mm, discriminant 2.559*sqPDG-0.472*dFov+15.117*SPBA-4.857 <0 [error 0% in 10 specimens]. Eqypt , Israel. Figs. 38–41 View FIGURES 38–41 ........................................................................................ israelica

29b Vertex with smaller, less demarcated and more spaced foveolae and with very weak or absent longitudinal microsculpture. Pubescence on gaster tergites less dense. Discriminant> 0 [error 0% in 51 specimens]............................. 30

30a Postpetiole and frons wider, pubescence hairs on gaster tergites shorter. With all measurements in mm, discriminant 93.21* FRS +27.62*PpW-406.34* PLG-6.246 > 0 [error 0% in 44 specimens]. Continuously distributed from the S Ukraine (32°E) eastwards to N Xinjang (88°E). Figs. 22–25 View FIGURES 22–25 ..................................................... ulianini

30b Postpetiole and frons narrower, pubescence hairs on gaster tergites longer. Discriminant 93.21* FRS +27.62*PpW-406.34* PLG-6.246 <0 [error 0% in 7 specimens]..................................................................... 31

31a Postocular distance and postpetiole height much larger (PoOc/CL> 0.423, PpH/CS> 0.260). Foveolae on vertex mediad of eye with diffuse margins ( Fig. 29 View FIGURES 26–29 ). Anterior face of petiole node moderately sloping down ( Fig. 27 View FIGURES 26–29 ). SE Kazakhstan. Figs. 26–29 View FIGURES 26–29 .............................................................................................. littoralis

31b Postocular distance and postpetiole height smaller (PoOc/CL <0.423, PpH/CS <0.260). Foveolae on vertex mediad of eye more strongly demarcated and bicoronate ( Fig. 33 View FIGURES 30–33 ). Anterior face of petiole node steeper ( Fig. 31 View FIGURES 30–33 ). Iranian Caspi region. Figs. 30–33 View FIGURES 30–33 .................................................................................. caspiense n. sp.

FRS

Falconer Museum

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Formicidae

Genus

Cardiocondyla

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