Temnothorax, Mayr, 1861

Prebus, Matthew M., Nguyen, Nhi, Doering, Grant Navid & Booher, Douglas B., 2024, Temnothorax caryaluteus sp. nov. (Hymenoptera: Formicidae): a new ant species from the eastern United States, European Journal of Taxonomy 970, pp. 175-202 : 189-198

Synopsis of Temnothorax species of the eastern United States:

Temnothorax allardycei (Mann, 1920)

Temnothorax ambiguus (Emery, 1895)

Temnothorax americanus (Emery, 1895)

Temnothorax bradleyi (Wheeler, 1913)

Temnothorax caryaluteus sp. nov.

Temnothorax curvispinosus (Mayr, 1866)

Temnothorax duloticus (Wesson, 1937)

Temnothorax longispinosus (Roger, 1863)

Temnothorax minutissimus (Smith, 1942)

Temnothorax palustris (Cover & Deyrup, 2004)

Temnothorax pergandei (Emery, 1895)

Temnothorax pilagens Seifert et al., 2014

Temnothorax schaumii (Roger, 1863)

Temnothorax smithi (Baroni Urbani, 1978)

Temnothorax texanus (Wheeler, 1903)

Temnothorax torrei (Aguayo, 1931)

Temnothorax tuscaloosae ( Wilson, 1951)

Key to Temnothorax species of the eastern United States based on the worker caste

1. Antennae with 11 segments ............................................................................................................... 2

– Antennae with 12 segments ............................................................................................................. 13

2. Antennal scrobe present; mandible with 3-4 teeth (see Fig. 6a ); dulotic social parasite of T. ambiguus , T. curvispinosus and T. longispinosus ; widespread: Quebec, Canada south to Georgia, west to Kansas................................................................................................... T. americanus (Emery, 1895)

– Antennal scrobe absent; mandible variable, but usually with 5 teeth (see Fig. 6b ); social parasite or free-living .......................................................................................................................................... 3

3. Only apical and preapical masticatory teeth developed and acute, remainder of masticatory teeth reduced to shallow crenulae (see Fig. 7a ).......................................................................................... 4

– Masticatory teeth well developed, with 5 acute teeth (see Fig. 7b )................................................... 5

4. Only known from the sexual castes; queen minute: ~ 3 mm in length ( Fig. 8a ); obligate inquiline social parasite of T. curvispinosus ; rare: New York south to North Carolina, west to Indiana and Michigan .................................................................................... T. minutissimus (M.R. Smith, 1942)

– Worker and sexual castes present ( Fig. 8b ); queen larger:> 3 mm in length; dulotic social parasite of T. ambiguus and T. longispinosus ; rare: Vermont, west to Ontario and Michigan .............................................................................................. T. pilagens Seifert et al., 2014

5. Antennal scapes short, failing to reach the posterior margin of the head by ≥ 2 antennal scape widths when fully retracted (see Fig. 9a–c ); arboreal species nesting in dead branches on live trees, in tree cavities, or under bark.............................................................6 (rugatulus clade sensu Prebus 2021)

– Antennal scapes long: if failing to reach the posterior margin of the head when fully retracted, then they do so by <2 (usually <1) antennal scape widths (see Fig. 9d–f ); arboreal or not ..................................................................................................................8 ( longispinosus group)

6. Propodeal spines long: about as long as the propodeal declivity in profile view (see Fig. 10a ); nests in cavities under bark; widespread: Ohio south to Florida, west to Mississippi and Indiana ............................................................................................... T. smithi (Baroni Urbani, 1978)

– Propodeal spines short: shorter than the propodeal declivity in profile view (see Fig. 10b–c ); widespread; nesting under bark or in branches.................................................................................. 7

7. Head densely sculptured in full face view: covered in longitudinal rugae, with the interstices densely areolate (see Fig. 11a ); nests in hollow cavities under bark; North Carolina south to Florida, west to Louisiana and Tennessee ............................................................... T. bradleyi (W.M. Wheeler, 1913)

– Head less sculptured in full face view: mostly smooth and shining, with weak longitudinal rugulae and weak areolae around the compound eyes and radiating posteriorly from the antennal insertions (see Fig. 11b ); nests in upper branches of mature oaks and hickories; widespread: Maine south to Florida, west to New Mexico and Nebraska .............................................. T. schaumii (Roger, 1863)

8. Subpostpetiolar process present and enlarged (see Fig. 12a ); dulotic social parasite of T. ambiguus , T. curvispinosus , and T. longispinosus ; New York south to Georgia, west to Illinois ............................................................................................. T. duloticus (L.G. Wesson, 1937)

– Subpostpetiolar process absent or weakly developed (see Fig. 12b–c ); free living species.............. 9

9. Propodeal spines shorter than, or as long as, the propodeal declivity in profile view (see Fig. 13a–b ) ......................................................................................................................................................... 10

– Propodeal spines much longer than the propodeal declivity in profile view (see Fig. 13c–d ) ........ 12

10. Dorsum of mesosoma mostly smooth and shining (see Fig. 14a ); workers small: ~ 2 mm in length; head, mesosoma, and gaster with dark integument; nests in small cavities in soil, hickory nuts, or acorns; Virginia south to Florida, west to Mississippi and Tennessee ................................................. ............................................................................................................. T. tuscaloosae ( Wilson, 1951)

– Dorsum of mesosoma sculptured (see Fig. 14b ); workers larger:> 3 mm in length; head, mesosoma, and gaster with light colored integument..........................................................................................11

11. Propodeal spines closely approximated at base, their union forming a U-shape with a narrow base (see Fig. 15a ); petiolar node acute to narrowly rounded in profile view, narrower than petiole in dorsal view (see Fig.15a ); mesosoma slightly arched in profile view (see Fig. 15b ); nests in hollow twigs, in branches, and under bark on live trees; widespread: Delaware south to Mississippi, west to Oklahoma (see Fig. 5 )...................................................................................... T. caryaluteus sp. nov.

– Propodeal spines further apart at base, their union forming a squared-off, broad-based U-shape (see Fig. 15c ); petiolar node broadly rounded or with a distinct dorsal face in profile view, about as broad as petiole in dorsal view (see Fig. 15c ); mesosoma flat in profile view (see Fig. 15d ); nests in hollow acorns, hickory nuts, and hollow twigs in the leaf litter; widespread: Nova Scotia south to West Virginia, west to South Dakota and Manitoba (see Fig. 4 )...................... T. ambiguus (Emery, 1895)

12. Integument typically light colored; head densely sculptured (see Fig. 16a ); propodeal spines bent in profile view (see Fig. 16b ); nests in hollow acorns, hickory nuts, and hollow twigs in the leaf litter; widespread: New Hampshire south to Florida, west to Oklahoma and Iowa (see Fig. 5 )................................................................................................... T. curvispinosus (Mayr, 1866)

– Integument typically dark colored; head sculpture variable, ranging from mostly smooth to densely sculptured (see Fig. 16c ); propodeal spines straight in profile view (see Fig. 16d ); nests in hollow acorns, hickory nuts, and hollow twigs in the leaf litter; widespread: Quebec, Canada south to Georgia, west to Arkansas and Minnesota......................................... T. longispinosus (Roger, 1863)

13. Metanotal groove deeply impressed (see Fig. 17a ); nests in stumps, logs, nutshells, or in the soil; widespread: New Jersey south to Hidalgo, Mexico, west to Arizona and Nebraska........................... ................................................................................................................. T. pergandei (Emery, 1895)

– Metanotal groove not deeply impressed (see Fig. 17b–c ) ............................................................... 14

14. Mesosoma arched (see Fig. 17b ) ..................................................................................................... 15

– mesosoma not arched (see Fig. 17c )................................................................................................ 16

15. Dorsum of petiole with two setae (see Fig. 18a ); head lightly sculptured (see Fig. 18b ); nesting in leaf litter; southern Florida and the Caribbean ............................................. T. torrei (Aguayo, 1931)

– Dorsum of petiole with> 2 setae (see Fig. 18c ); head densely sculptured (see Fig. 18d ); nesting in hollow twigs, vines, and culms of sawgrass; southern Florida and the Caribbean ............................. .................................................................................................................. T. allardycei (Mann, 1920)

16. Integument typically dark colored; postpetiole wider than long in dorsal view (see Fig. 19a ); ground nesting; occurring in open to semi-open sites with well-drained soil; widespread: Massachusetts south to Florida, west to New Mexico and Minnesota ................... T. texanus (W.M. Wheeler, 1903)

– Integument typically light colored; postpetiole about as wide as long in dorsal view (see Fig. 19b ); ground nesting; occurs in marshes of the Florida panhandle .... T. palustris (Cover & Deyrup, 2004)

Figures

Fig. 6. Comparison of antennal scrobe and mandibular dentition characters in full face view. a. Temnothorax americanus (Emery, 1895) (☿, CASC, CASENT0104553). b. T. curvispinosus (Mayr, 1866) (☿, ABS, CASENT0104032). Photographs by April Nobile. Scale bars 0.2 mm.

Fig. 7. Comparison of mandibular dentition characters in full face view a. Temnothorax minutissimus (Smith, 1942) (♀, LACM, CASENT0172598). b. T. curvispinosus (Mayr, 1866) (☿, ABS, CASENT0104032). Photographs by April Nobile. Scale bars 0.2 mm.

Fig. 8. Comparison of Temnothorax minutissimus (Smith, 1942) and T. pilagens Seifert et al., 2014 in profile view. a. Temnothorax minutissimus (♀, LACM, CASENT0172598; photograph by April Nobile). b. T. pilagens (☿, MMPC, CASENT0868793; photograph by Matthew Prebus). Scale bars 0.2 mm.

Fig. 9. Comparison of antennal scape lengths in full face view. a. Temnothorax bradleyi (Wheeler, 1913) (☿, ABS, CASENT0104011; photograph by April Nobile). b. T. schaumii (Roger, 1863) (☿, ABS, CASENT0104047; photograph by April Nobile). c. T. smithi (Baroni Urbani, 1978) (☿, ABS, CASENT0104053; photograph by April Nobile). d. T. caryaluteus sp. nov. (holotype ☿, USNM, CASENT4011115; photograph by Matthew Prebus). e. T. duloticus (Wesson, 1937) (☿, USNM, CASENT0103163; photograph by April Nobile). f. T. ambiguus (Emery, 1895) (☿, MSNG, CASENT0904763; photograph by Will Ericson). Scale bars 0.2 mm.

Fig. 10. Comparison of Temnothorax propodeal spines in profile view; inset drawings depict propodeal spine length (dotted outlines) in comparison to length of the propodeal declivity. a. Temnothorax bradleyi (Wheeler, 1913) (☿, ABS, CASENT0104011). b. T. smithi (Baroni Urbani, 1978) (☿, ABS, CASENT0104053). c. T. schaumii (Roger, 1863) (☿, ABS, CASENT0104047). Photographs by April Nobile, from www.antweb.org. Scale bars 0.2 mm.

Fig. 11. Comparison of head integument sculpture in full face view. a. Temnothorax bradleyi (Wheeler, 1913) (☿, ABS, CASENT0104011). b. T. schaumii (Roger, 1863) (☿, ABS, CASENT0104047). Photographs by April Nobile, from www.antweb.org. Scale bars 0.2 mm.

Fig. 12. Comparison of subpostpetiolar processes in profile view. a. Temnothorax duloticus (Wesson, 1937) (☿, SMNG, ANTWEB1008479; photograph by Roland Schultz). b. T. ambiguus (Emery, 1895) (☿, UCDC, CASENT0104803; photograph by April Nobile). c. T. longispinosus (Roger, 1863) (☿, USNM, CASENT0105559; photograph by Dan Kjar). Scale bars 0.2 mm.

Fig. 13. Comparison of Temnothorax propodeal spines in profile view; inset drawings depict propodeal spine length (dotted outlines) in comparison to length of the propodeal declivity a. T. ambiguus (Emery, 1895) (☿, UCDC, CASENT0104803; photograph by April Nobile). b. T. tuscaloosae (Wilson, 1951) (syntype ☿, MCZC; photograph by Gary Alpert). c. T. curvispinosus (Mayr, 1866) (☿, ABS, CASENT0104040; photograph by April Nobile). d. T. longispinosus (Roger, 1863) (☿, USNM, CASENT0105559; photograph by Dan Kjar). Scale bars 0.2 mm.

Fig. 14. Comparison of mesosoma integument sculpture in dorsal view. a. Temnothorax tuscaloosae (Wilson, 1951) (syntype ☿, MCZC; photograph by Gary Alpert). b. T. ambiguus (Emery, 1895) (☿, UCDC, CASENT0104803; photograph by April Nobile). Scale bars 0.2 mm.

Fig. 15. Comparison of propodeal spine and mesosoma profile characters. a–b. Temnothorax caryaluteus sp. nov. (holotype ☿, USNM, CASENT4011115, photographs by Matthew Prebus). a. Dorsal view. b. Profile view. c–d. T. ambiguus (Emery, 1895) (☿, UCDC, CASENT0104803, photographs by April Nobile). c. Dorsal view. d. Profile view. Scale bars 0.2 mm.

Fig. 5. Distribution map comparing the ranges of Temnothorax caryaluteus sp. nov., T. ambiguus (Emery, 1895), and T. curvispinosus (Mayr, 1866) in North America.

Fig. 4. Castes of Temnothorax caryaluteus sp. nov. a–c. Holotype ☿ (USNM, CASENT4011115). a. Full face view. b. Profile view. c. Dorsal view. d–f. Paratype ♀ (USNM, CASENT4011128). d. Full face view. e. Profile view. f. Dorsal view. g–i. Non-type ♂ (USNM, CASENT4012896). g. Full face view. h. Profile view. i. Dorsal view. Scale bars 0.2 mm.

Fig. 16. Comparison of head integument sculpture and propodeal spine characters. a–b. Temnothorax curvispinosus (Mayr, 1866). a. Full face view (☿, NHMUK, CASENT0901789; photograph by Will Ericson). b. Profile view (☿, ABS, CASENT0104040; photograph by April Nobile). c–d. T. longispinosus (Roger, 1863). c. Full face view (☿, CASC, CASENT0914508; photograph by Dominique Monie). d. Profile view (☿, USNM, CASENT0105559; photograph by Dan Kjar). Scale bars 0.2 mm.

Fig. 17. Comparison of mesosoma profile characters in profile view. a. Temnothorax pergandei (Emery, 1895) (☿, ABS, CASENT0104016; photograph by April Nobile). b. T. allardycei (Mann, 1920) (☿, ABS, CASENT0104009; photograph by April Nobile). c. T. texanus (Wheeler, 1903) (☿, CASC, CASENT0923379; photograph by Michele Esposito). Scale bars 0.2 mm.

Fig. 18. Comparison of propodeal node setae and head integument sculpture. a–b. Temnothorax torrei (Aguayo, 1931) (☿, MCZC, MCZENT00583611, photograph by Matthew Prebus). a. Profile view. b. Full face view. c–d. T. allardycei (Mann, 1920) (☿, ABS, CASENT0104009; photograph by April Nobile). c. Profile view. d. Full face view. Scale bars 0.2 mm.

Fig. 19. Comparison of postpetiole proportions in dorsal view. a. Temnothorax texanus (Wheeler, 1903) (☿, ABS, CASENT0104063). b. T. palustris (Cover & Deyrup, 2004) (☿, ABS, CASENT0104045). Photographs by April Nobile. Scale bars 0.2 mm.