Williamstilla Lelej, 2023

Lelej, A. S., 2023, Review of the tribe Ctenotillini (Hymenoptera: Mutillidae) from Oriental and Palaearctic regions, Far Eastern Entomologist 480, pp. 1-22 : 16-18

Genus Williamstilla Lelej , gen. n.

https://zoobank.org/NomenclaturalActs/ A27D4891-3152-4CA1-AB82-A285AC584781

Ctenotilla : Lelej, 1992: 282, ♀; 2005, 34. part.; Williams et al., 2019: 15 , ♀; Pagliano et al., 2020: 161, part.

Type species: Ctenotilla guangdongensis Lelej, 1992 , designated here.

DIAGNOSIS. MALE. T4–6 with medial longitudinal carina. S7 with strong lateral process curved inward. S8 medially with highly elevated wide shiny longitudinal part bordered by long setae. Apical part of gonostylus sharply down curved. Five-six basal metasomal segments ferruginous-red. FEMALE. Inner margin of mandible without subbasal denticle. Pygidial plate microreticulate and carinated laterally. T2 without two subbasal white spots disposed transversely, T2 apically and T3 with medially interrupted band of yellowish setae.

DESCRIPTION. MALE. Head not rounded posterad, dorsally with well-defined preoccipital carina. Eyes weakly notched inside. Prementum strongly tuberculate. Mandible with preapical tooth on inner border, well-defined dorsal curved carina and large triangle lobe beneath. Scape curved with upper defined carina, space below carina punctured, setose. Ocelli small. Antennal tubercle large, carinated, transverse carina between torulus and eye defined. Tegula large, projecting over mesoscuto-scutellar suture. Pterostigma large closed, not sclerotized. Radial cell slightly longer than first radio-medial cell. Mesopleuron beneath swollen, without tooth. T2 with long lateral felt line, S2 without any lateral felt line. S7 with strong lateral process curved inward. S8 medially with highly elevated wide shiny longitudinal part bordered by long setae. Gonostylus inside preapically with triangle widening. Apical part of gonostylus sharply down curved. Parapenial lode ventrally dentate.

FEMALE. Prementum with weak distinct basal tubercle. Hypostomal carina with tooth closer to mandibular base. Genal carina weak, not tuberculate posterad. Clypeus

Figs 30–35. Wiiliamstilla guangdongensis . 30–32 – ♀, paratype; 33–34, ♂. 30, 31, 33, 34 – habitus (30, 33 – dorsal view, 31, 34 – lateral view); 32 – T6, pygidial plate; 35 – S7–8, posterolateroventral view.

more or less gently sloping with small basomedial tubercle, anterior margin weakly rounded, not tuberculate. F1 1.4 times as long as F2, F2–4 weakly emarginated beneath. Pronotum with well-defined humeral carina. Propodeum posterodorsally with complete row of spines, middle spine longest. Ratio width of T1/propodeum = 0.8. T1 apicodorsally with fringe of yellowish setae. T2 without two subbasal white spots disposed transversely, T2 apically and T3 with medially interrupted band of yellowish setae. Pygidial plate elongated, microreticulate, apically rounded, carinated laterally and apically.

SPECIES INCLUDED. Type species only, Williamstilla guangdongensis ( Lelej, 1992) , comb. n.

DISTRIBUTION. China: Guangdong, Thailand, Laos, Vietnam.

REMARKS. The male of Williamstilla gen. n. belongs to the group with medial carina on T4–6 but differs by having S7 with strong lateral process curved inward (S7 at most with lateral tubercle in other genera), by S8 medially with highly elevated wide shiny longitudinal part (S8 medially invaginated in other genera), by apical part of gonostylus sharply down curved (gonostylus gently down curved in other genera). The female of new genus belong to the group with granulose pygidial plate, but differs by having T2 without two subbasal white spots disposed transversely (T2 with two basal white spots disposed transversely in Denistilla ) and by T2 apically and T3 with medially interrupted band of pale setae (T2 apically and T3 with non interrupted band of pale setae in Cephalotilla and Ctenotilla ). The female of Williamstilla gen. n. is similar to the female of Afrotropical genus Chaetomutilla Nonveiller, 1979 , especially Ch. fornasinii (Gribodo, 1894) , but differs by wider T1.

ETYMOLOGY. I am delighted to name this new genus in honor of Kevin A. Williams, world authority on Mutillidae and my best colleague with a common suffix for mutillid genera. Gender feminine.