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Key to Technomyrmex of Thailand and Laos
Key to Thai and Lao species based on worker caste, from Jaitrong & Yamane (2024), modified from Bolton (2007). Most intercaste specimens can also be identified using this key.
1
- Dorsal surface of frontal carinae, or area immediately mesad of frontal carinae, with 1–4 erect setae (Fig. 1A, B, C); at least one erect seta present somewhere along length of frontal carinae => 2
- Dorsal surface of frontal carina and area immediately mesad of frontal carina entirely without erect setae (Fig. 1D, E) => 14
Jaitrong & Yamane (2024), Fig. 1. Characters used in the key to the Thai and Lao Technomyrmex species. A–E, head in profile view showing condition of setae; F–H, clypeus in full-face view. A, F, T. pratensis; B, G, T. grandis; C, H, T. albipes; D, T. obscurior; E, T. reductus. Red triangles on fig. A–C dedicated to long erect setae, D–E without erect setae. Photos by Yudthana Samung.
2
return to couplet #1
- Either dorsal (outer) surfaces of mid- and hindtibiae, or antennal scape, or both with erect/suberect setae => 3
- Both dorsal surfaces of mid- and hindtibiae and antennal scape without erect/suberect setae => 5
3
return to couplet #2
- Maxillary palps with five segments, labial palps with three segments; anterior clypeal margin with long (deep), narrow median notch, the length of which is at least equal to or longer than its maximum width; inner lateral margin of notch meets anterior clypeal margin in sharp angle on each side (Fig. 1F) => Technomyrmex pratensis
- Maxillary palps with six segments, labial palps with four segments; anterior clypeal margin almost transverse or at most with very shallow, weak median impression or feeble concavity that is much broader than long; if a weak concavity is present, it curves evenly into lateral portion of anterior clypeal margin (Fig. 1G–H) => 4
- Jaitrong & Yamane (2024), Fig. 1. Characters used in the key to the Thai and Lao Technomyrmex species. A–E, head in profile view showing condition of setae; F–H, clypeus in full-face view. A, F, T. pratensis; B, G, T. grandis; C, H, T. albipes; D, T. obscurior; E, T. reductus. Red triangles on fig. A–C dedicated to long erect setae, D–E without erect setae. Photos by Yudthana Samung.
4
return to couplet #3
- Longest erect setae on gastral tergite I longer than maximum diameter of eye; erect setae abundant, very dense and long on all body surfaces => Technomyrmex grandis
- Longest erect setae on gastral tergite I shorter than maximum diameter of eye; erect setae present on all dorsal surfaces but short and sparse => Technomyrmex wheeleri
5
return to couplet #2
- Dorsum of head and gastral tergite I glassy, smooth and shiny => 6
- Dorsum of head and gastral tergite I with fine sculpture, i.e., reticulate, reticulate-shargreened, or finely punctate => 7
6
return to couplet #5
- Median portion of anterior clypeal margin distinctly concave; mesopleuron, mesonotum and propodeum strongly and densely punctate, matt => Technomyrmex strenuus
- Median portion of anterior clypeal margin entire or very shallowly emarginate; mesopleuron, mesonotum and propodeum much weakly punctate and rather shiny => Technomyrmex tatius
7
return to couplet #5
- Dorsum of head behind level of posterior margin of eye entirely without erect setae (Fig. 2A) => 8
- Dorsum of head behind level of posterior margin of eye with one or more pairs of erect setae (Fig. 2B) => 12
Jaitrong & Yamane (2024), Fig. 2. Technomyrmex albipes species group. A, C, T. brunneus; B, D, T. difficilis. A, B, Head in profile; C, D, mandibles in full-face view. Red triangle on fig. A shows the head without erect setae, B the head with erect setae, C mandibles with longitudinal groove, D mandibles without longitudinal groove. Photos by Yudthana Samung.
8
return to couplet #7
- Mandibles with longitudinal groove located close to their outer margin (Fig. 2C); with head in full-face view eyes located distinctly more posteriorly on head, at or slightly behind midlength, EPI > 110 => Technomyrmex brunneus
- Mandibles without longitudinal groove anywhere (Fig. 2D); with head in full-face view eyes located distinctly more anteriorly on head, in front of midlength, EPI < 95 => 9
- Jaitrong & Yamane (2024), Fig. 2. Technomyrmex albipes species group. A, C, T. brunneus; B, D, T. difficilis. A, B, Head in profile; C, D, mandibles in full-face view. Red triangle on fig. A shows the head without erect setae, B the head with erect setae, C mandibles with longitudinal groove, D mandibles without longitudinal groove. Photos by Yudthana Samung.
9
return to couplet #8
- With head in full-face view, posterior margin broadly emarginate across its width; anterior clypeal margin with small but sharply defined semicircular median notch; head broader, CI ≥ 100 => Technomyrmex elatior
- With head in full-face view, posterior margin with small, shallow median indentation only; anterior clypeal margin with at most weak and very shallow median concavity; head narrower, CI 77–90 => 10
10
return to couplet #9
- Propodeum in profile with dorsum convex and curving into declivity; erect setae on gastral tergite I distinctly longer than maximum diameter of eye; pronotum, mesonotum and propodeum all inflated and with swollen appearance; pronotum broader, PW 0.46 mm; scapes relatively longer, SI 118 => Technomyrmex butteli
- Propodeum in profile with dorsum flat or nearly flat and meeting declivity in blunt or sharply defined angle; erect hairs on gastral tergite I usually shorter than or at most equal to maximum diameter of eye; pronotum, mesonotum and propodeum not inflated, without swollen appearance; pronotum narrower, PW 0.33–0.43 mm; scapes relatively shorter, SI 93–112 => 11
11
return to couplet #10
- Scapes relatively short (SI 93–100); in dorsal view promesonotum relatively short and broad; eyes somewhat smaller (OI 27–28); with propodeum in profile view junction of dorsum and declivity tends to be blunt; mid- and hindcoxae usually dark-colored => Technomyrmex albipes
- Scapes relatively long (SI 111–112); in dorsal view promesonotum relatively long and narrow; eyes somewhat larger (OI 31–33); with propodeum in profile view junction of dorsum and declivity tends to be more sharply angled; mid- and hindcoxae usually whitish or yellowish => Technomyrmex vitiensis
12
return to couplet #7
- Anterior clypeal margin at most with poorly defined median indentation or very shallow median concavity; smaller species, HW 0.53–0.59 => Technomyrmex difficilis
- Anterior clypeal margin with sharply defined conspicuous median concavity that is semicircular to deeply inverse-U-shaped; larger species, HW 0.86–1.02 => 13
13
return to couplet #12
- Vertex with erect setae present near posterior margin of head; inner margin of clypeal notch meets lateral portion of anterior clypeal margin in sharp angle on each side; erect hairs on gastral tergites I–II sparse and short, longest setae less than half as long as maximum diameter of eye; erect setae on gastral tergite IV about twice as long as those on tergite I–II => Technomyrmex yamanei
- Vertex without erect setae near posterior margin of head; inner margin of clypeal notch curves bluntly into lateral portion of anterior clypeal margin on each side; setae on gastral tergites I–II numerous and conspicuous, longest setae about equal to maximum diameter of eye or only slightly shorter => Technomyrmex modiglianii
14
return to couplet #1
- Gastral tergite II without erect setae => 15
- Gastral tergite II with at least one pair of erect setae => 16
15
return to couplet #14
- Body larger (TL 3.30–4.46 mm; HW 0.79–1.29 mm); gastral tergite III with transverse row of 6–8 erect setae; anterior clypeal margin with conspicuous, long, inverse-U-shaped median notch; strongly polymorphic species => Technomyrmex lisae
- Body much smaller (TL 2.54 mm; HW 0.53 mm); gastral tergite III without erect setae; anterior clypeal margin with small, shallow median impression or weak indentation; monomorphic species => Technomyrmex dubius
16
return to couplet #14
- Maxillary palps with four segments, labial palps with three segments; erect setae on gastral tergites II–III extremely short and inconspicuous, only about 0.2 × maximum diameter of eye => 17
- Maxillary palps with six segments, labial palps with four segments; erect setae on gastral tergites II–III long and conspicuous, about 0.5 × maximum diameter of eye => 18
17
return to couplet #16
- Gastral tergite II with short erect setae (Fig. 42B); pronotal setae longer than diameter of propodeal spiracle (Fig. 42A); larger species (TL 2.97–3.47 mm; HW 0.63–0.69 mm); body black => Technomyrmex champasakensis
- Gastral tergite II without short erect setae (Fig. 42D); pronotal setae shorter than diameter of propodeal spiracle (Fig. 42C); smaller species (TL 2.87–2.97 mm; HW 0.59–0.66 mm); body reddish brown => Technomyrmex reductus
18
return to couplet #17
- In profile either head, mesosoma, and gaster all yellow to light yellowish brown, or head or gaster, or often both slightly darker in shade than mesosoma => 19
- In profile head, mesosoma, and gaster brown to back, all three the same shade or very near so => 20
19
return to couplet #18
- Propodeal junction bluntly angulate (Fig. 21A); metathoracic spiracle generally located far from posterior margin of metanotal groove (northern Thailand) => Technomyrmex horni
- Propodeal junction roundly convex (Fig. 29A); metathoracic spiracle generally located close to posterioy margin of metanotal groove (northeastern, eastern and southern Thailand) => Technomyrmex schimmeri
20
return to couplet #18
- Propodeum in profile with relatively long, flat dorsal surface; length of dorsum almost twice depth of declivity to spiracle, or more => Technomyrmex obscurior
- Propodeum in profile with relatively short, convex or almost flat dorsal surface; length of dorsum shorter => 21
21
return to couplet #20
- Mid- and hindcoxae off-white to yellow, distinctly much lighter in color than femora and mesosoma, and strongly contrasting with them => Technomyrmex kraepelini
- Mid- and hindcoxae pale to dark brown, about same color as femora and mesosoma, not strongly contrasting with them => Technomyrmex sundaicus
References
- Bolton, B. 2007. Taxonomy of the dolichoderine ant genus Technomyrmex Mayr (Hymenoptera: Formicidae) based on the worker caste. Contributions of the American Entomological Institute. 35(1):1-149.
- Jaitrong, W., Yamane, S. 2024. A revision of the ants Technomyrmex Mayr, 1872 (Hymenoptera: Formicidae: Dolichoderinae) in Thailand and Laos. Natural History Bulletin of the Siam Society 66 (1): 29–118.