708 M. W. R. de V. GRAHAM 



The males of Trichomalus are still rather imperfectly known. They would 

 repay further investigation because they often show good characters ; in the case 

 of some closely-allied species (e.g., campestris and inops) the males are easy to 

 distinguish although their females are very similar. I am providing a tentative 

 key to the males of some European species, so that at least a number of the more 

 distinct ones may be recognized. Where particular males have been only doubtfully 

 correlated with females, a query is inserted before the name. 



Key to most European Species 



(Females) 



i Fore coxae entirely reddish testaceous or (rarely) infuscate at extreme base 



only. Fore wing with basal vein bare ; marginal vein only 1-25-1-5 times 

 as long as the stigmal vein ; surface beyond the speculum with relatively 

 dense pilosity ........... 33 



- Fore coxae in most species mainly to entirely black with a metallic tinge, 



rarely only black on their external aspect, in which case the basal vein of 

 the fore wing is pilose. Fore wing with marginal vein sometimes longer 

 in relation to the stigmal vein ; surface beyond the speculum often less 

 densely pilose ........... 2 



2 (1) Propodeum with nucha strongly reticulate, and often relatively large . . 3 



- Propodeum with nucha weakly reticulate, transversely aciculate, or alutaceous, 



often relatively short .......... 11 



3 (2) Basal vein of fore wing bare ...... sp. indet. B (p. 736) 



- Basal vein of fore wing pilose ......... 4 



4 (3) Propodeum: panels of median area relatively dull, strongly and nearly 



uniformly reticulate, nearly as strongly as the nucha, though rather more 

 finely ; costula usually absent or vaguely indicated, if at all distinct then 

 not straight. Gaster without purplish transverse fasciae on the tergites, 

 though its disc is often indefinitely suffused with purplish or violet-bronze 5 



- Propodeum with panels of median area more weakly or irregularly sculptured, 



usually relatively shiny and sometimes nearly smooth ; costula nearly 

 always present, straight and often sharp (Text-fig. 583) . Gaster most often 

 with purplish or purplish bronze transverse fasciae on the hinder part of 

 some of the tergites .......... 9 



5 (4) Head in dorsal view (Text-fig. 585) with temples less strongly convergent, 



and one third or slightly more than one third as long as the eyes ; head 

 about 1-3 times as broad as the mesoscutum. Antennal flagellum testa- 

 ceous, at least beneath ; legs except coxae testaceous ; head and thorax 

 tending towards bright green .... repandus (Walker) (p. 722) 



- Head in dorsal view (Text-fig. 584) with temples more convergent, from one 



fifth to hardly more than one quarter as long as eyes ; head at most 1-2 

 times as broad as the mesoscutum. Antennal flagellum fuscous to black ; 

 legs often relatively darker ; head and thorax most often a dull or bronze - 

 green, sometimes bronze or coppery ....... 6 



6 (5) More elongate species : gaster lanceolate-ovate, slightly longer than head 



plus thorax, 2-2-2-5 times as long as broad, reaching level with the tips of 



the fore wings when these are laid back. . . oxygyne sp. n. (p. 720) 



- Less elongate species : gaster ovate, 1-5-2-0 times as long as broad, at least 



slightly shorter than head plus thorax, at least not quite reaching the tips 



of the fore wings when these are laid back ...... 7 



