THEREVA. 297 



Table of Genera. 



First autennal joint nearly as long as head . . PHYCUS, Walk., p. 306. 

 First antennal joint much shorter than head. 

 Face and frons with long dense pubes- 

 cence THEHEVA, Latr., p. 297. 



Face bare ; frons bare, or with com- [p. 302. 



paratively short pubescence in J PSILOCEPHALA, Zett., 



Genus THEREVA, Latr. 



Thereva, Latreille, Precis Car. Gen. Ins. p. 167 (1796) ; id., Hist. 

 Nat. Crust. Ins. iii, p. 441 (1802). 



GENOTYPE, Musca plebeja, L. (Europe). 



Head semicircular, placed closely on thorax ; frons slightly 

 produced towards antennae, densely pubescent in tf , shortly so 

 in $ , a transverse shining black callus present in ; face sloping, 

 covered thicldy (as is all the lower part of the head) in <$ with 

 dense pubescence, in 5 pubescence much shorter: three ocelli. 

 Proboscis' of moderate length, rather upturned, labella large; 

 palpi cylindrical, thin, pubescent. Eyes bare, contiguous in c? 

 for some distance, wide apart in 5 Antennas porrect, approxi- 

 mate at base, rather long; 1st two joints cylindrical, bristly and 

 pubescent ; the 2nd short ; 3rd narrowed at base, elongate- 

 conical, sometimes indistinctly annulated near base, bare, bearing 

 a short style ending in a minute filament. Thorax oval, densely 

 pubescent in <5 , less so in $ . Three to six presutural, two supra- 

 alar, one postalar. and one or two pairs of prescutellar bristles, 

 all strong and black, but the latter ones liable to variation. 

 Scut ell u in semicircular, with four marginal bristles; metariotum 

 small, bare. Abdomen conical, longer than thorax, with seven or 

 eight segments in J , the 8th always distinct in $ , forming basal 

 portion of ovipositor ; pubescence dense and furry in <5 , shorter 

 in $> , and usually adpressed on basal segments. Genitalia not 

 prominent, but of'ten visible ; ovipositor with a circlet of strong 

 black spines. Legs moderately long, slender; some black bristles 

 on coxaB and anterior femora ; tibiae with rows of small bristles and 

 a circlet of spines at tip. Wings with normal Therevid venation ; 

 4th posterior cell generally closed or narrowly open. 



Range. World-wide, but apparently better represented in 

 Europe and North America. 



Life-history. Partly known ; larvae very active, occurring in 

 damp earth, under stones, and in similar places ; possibly they 

 feed, at least occasionally, on Lepidopterous larvae. 



Only four species are known for certain from India ; these may 

 be separated as follows : 



Antemue mainly bright brownish yellow. . kempi, sp. n., p. 298. 

 Antennae wholly black. 



Legs all blackish niyella, Wied., p. 299. 



