Trypoxylon bicolor F. Smith, 1856

Pham, Phong Huy, Nguyen, Anh Thi & Antropov, A. V., 2023, New records of species of the genus Trypoxylon Latreille, 1796 (Hymenoptera: Crabronidae) from northern Vietnam, Russian Entomological Journal 32 (1), pp. 58-67 : 61-62

Trypoxylon bicolor F. Smith, 1856

Figs 1–2 , 17 .

SPECIMENS EXAMINED. Vietnam: Son La: 1 ♀ , Son La city, 20–30.viii.2017, Malaise trap, Coll. Khuat Dang Long ; 1 ♀, Kho Hong, Chieng Xuan, Van Ho, 13–18.vi.2018, Malaise trap, Coll. Phong Huy Pham. Hoa Binh: 2 ♀♀, My Tan, Tan Thanh, Luong Son , 27.v–27.vi.2019, 27.vi. 2019, Malaise trap, trap nest, Coll. Phong Huy Pham ; 1 ♀, Thanh Lap, Luong Son , 25.ix–5.x.2018, Malaise trap, Coll. Phong Huy Pham ; 6 ♀♀ + 5 ♂♂, Kim Boi, 25.iv– 5.v.2012, 5–15.vi.2012, 25.vi–5.vii.2012, 15–25.vii.2012, 5– 15.viii.2012, 15–25.viii.2012, 15–25.ix.2012, 5–15.xi.2012, 5– 15.vii.2018, Malaise trap, Colls. Khuat Dang Long and Hoa Thi Dang. Vinh Phuc: 4 ♀♀, Me Linh Station for Biodiversity, Ngoc Thach, Me Linh , 6–12.vi.2018, 12–25.vii.2018, trap nest, Coll. Phong Huy Pham. Thai Nguyen: 1 ♀, An Lac, Phu Luong , 22.vii– 9.viii.2018, Malaise trap, Coll. Hoa Thi Dang. Tuyen Quang: 1 ♀, Na Hang, 30.x–10.xi.2017, Malaise trap, Coll. Khuat Dang Long. Ha Giang: 1 ♀, Cao Bo, Vi Xuyen , 5–15.x.2001, Malaise trap .

DISTRIBUTION. Vietnam: Cao Bang, Ha Giang, Hoa Binh, Son La, Thai Nguyen, Vinh Phuc. China, Hawaii, India, Indonesia, Japan, Malaysia, Philippines, Singapore, Sri Lanka, Thailand [ Pulawski, 2022]. New record from Vietnam.

REMARKS. Trypoxylon bicolor is a member of the T. bicolor species group [ Tsuneki, 1981f]. Males of T. bicolor are very similar to those of T. petiolatum . Tsuneki [1979a] separated males of these two species only by measurement parameters of antennal segments, the colour of mid tibiae, shape of the pronotal lamina, and the body length. These external morphological characters are difficult to convince us of the identification of the males of the two in the Vietnamese specimens because of distinct variations of the characters. We, based on the Vietnamese specimens of the males of these two species, produce two morphological characters that are easy to distinguish between them as follows: in T. bicolor , the vertex conspicuously depressed and its surface lower than the vertical margin at the upper margin of eyes (in T. petiolatum , the vertex undepressed and its surface level to the vertical margin at the upper margin of eyes) and in T. bicolor , flagellomere 11 in lateral view lightly distinctly tapering ( Fig. 2 ) (in T. petiolatum , flagellomere 11 in lateral view not tapering, lightly curved medially) ( Fig. 4 ).

Both T. bicolor and T. petiolatum , based on collected specimens, are widely distributed in northern Vietnam. Whereas T. bicolor was collected only in highland areas, T. petiolatum was widely collected in both lowland and highland areas, but mainly in the lowland area.

Figures

Figs 1–4. Trypoxylon spp.: 1–2 — T. bicolor; 3–4 — T. petiolatum; 1, 3 — head in frontal view, female; 2, 4 — flagellum, male. Рис. 1–4. Trypoxylon spp.: 1–2 — T. bicolor; 3–4 — T. petiolatum; 1, 3 — голова спереди, самка; 2, 4 — жгутик, самец.

Figs 17–20. Trypoxylon spp, female habitus, lateral view: 17 — T. bicolor; 18 — T. cagrum; 19 — T. interruptum; 20 — T. orientale. Рис. 17–20. Trypoxylon spp, внешний вид самки сбоку: 17 — T. bicolor; 18 — T. cagrum; 19 — T. interruptum; 20 — T. orientale.