Smicromyrme songkhwae Sittichaya & Williams, 2022

Thaochan, Narit, Williams, Kevin A., Thoawan, Kodeeyah, Jeenthong, Tadsanai & Sittichaya, Wisut, 2022, Three new species and one new country record of velvet ants (Hymenoptera, Mutillidae) from Thailand, Journal of Hymenoptera Research 93, pp. 151-165 : 151

Smicromyrme songkhwae Sittichaya & Williams sp. nov.

Fig. 5

Material examined.

Holotype ♀, Thailand, Phitsanulok Province, Chat Trakan District, Phu Soi Dao National Park, Dry evergreen forest, 21.IV.2002. W. Jaitrong. (THNHM).

Diagnosis.

Female. This species can be recognized by the following combination of characters: the mesosoma is longer than wide; the scutellar scale is transversely arcuate, ~6 punctures wide; the T2 disc has a single mesal spot; the T2 posterior fringe and T3 are covered with whitish setae above lighter yellow-brown cuticle; the pygidium is elongate ovate with ~10 weakly incurved striae mostly ending before pygidial mid-point. Small species, 2.9 mm. long.

Male. Unknown.

Description.

Female. Body length 2.9 mm. Coloration. Head dark brown except frons, base of mandible, clypeus, and antenna yellowish brown; mesosoma orange-brown; legs yellowish brown, darker marginally and apically; metasoma dark brown, somewhat paler ventrally, except T1 and S1 orange-brown, and T2 posterior fringe and T3 mostly yellow brown. Body setae generally sparse and silvery, except appressed setae on T2and T4-5 setae blackish, and T2 basomedial spot, T2 apical margin, and T3 entirely whitish. Head. Width behind eye 1.13 × mesosoma width. Frons, vertex, and gena punctures tightly confluent. Frons surface rugose, forming transverse wavy carinules. Mandible apex apparently unidentate. Clypeus with obscure transverse carina; basomedial portion with weak flat tubercle. Antennal scrobe without dorsal carina. Antennal tubercle with weak punctures. Genal carina obscure, not reaching hypostomal carina. F1 1.0 × pedicel length, F2 1.15 × pedicel length. Mesosoma. Length 1.05 × width. Dorsum of mesosoma with small coarse confluent punctures. Mesopleural lamella absent. Humeral carina present, weakly developed. Ratio of width of humeral angle, anterior spiracle, narrowest point of mesonotum, propodeal spiracle, and widest point of propodeum 38:40:37:38:39. Scutellar scale transversely arcuate, ~6 punctures wide, forming transverse isosceles carina in posterior view. Posterior propodeal face with upper portion areolate, lower portion shagreened without punctures. Lateral and posterior propodeal faces not separated by carina. Metatibio-tarsal ratio 34:18:11:9:7:6. Metasoma. T1-5 with small dense punctures, sparser on T1. S1 without longitudinal carina. T2 felt line 0.40 × T2 total length. T6 with long ovate pygidial plate, with ~10 laterally incurved striae mostly ending before pygidial midpoint. S6 posterior margin bidentate.

Male. Unknown.

Distribution.

Thailand (Phitsanulok Province).

Etymology.

This name refers to an old name for Phitsanulok Province (song =two in the Thai numeral system and khwae =tributary), the type specimen locality. Treat as a noun in apposition.

Remarks.

In the key to female velvet ants in southern Thailand ( Williams et al. 2019), this species terminates at couplet 25 with S. helarctos Williams in Williams et al. 2019) and S. borkenti Williams in Williams et al. 2019; currently Andreimyrme borkenti , see Okayasu et al. 2021). Unlike A. borkenti , the scutellar scale is wide and the pygidial plate is widest mesally. Furthermore, this species does not belong in Andreimyrme based on the unidentate mandible, unarmed prementum, and wide distinct scutellar scale (Okayasu et al. 2021b).

Based on similarities in the scutellar scale, pygidial shape, and light brown cuticle of the T2 fringe and T3, this species is apparently closely related to S. helarctos . Unlike that species, S. songkhwae has the mesosoma uniformly orange-brown (blackened laterally in S. helarctos ) and longer than wide (as wide as long in S. helarctos ). Additionally, the pygidial striae in S. songkhwae are fainter and restricted to the anterior half of the pygidial plate (pygidial striae distinct and extending beyond midpoint in S. helarctos ).

Figures

Figure 5. Smicromyrme songkhwae sp. nov., holotype, female A dorsal view B posterior propodeal face and metasoma dorsum C lateral view D frons and vertex E clypeus F pygidium