610 

 THE OOTHECA OF AN ASILID. 



BY 



J. 0. Kershaw, f.z.s., f.e.s. 

 (With Plates A and B). 



The ootheca of this Asilid* (Provnachus, sp.), which is very com- 

 mon in Kwangtung Province, S. China, is affixed to the upper 

 end of long, coarse grass-stalks, the bare ends of twigs of woody 

 herbs and such-like situations, usually two or three feet above the 

 ground. Where the flies are numerous — along hedge-rows on the 

 outskirts of woods and patches of vegetation — these egg-cases may 

 be found in dozens during May and June, the flies constructing 

 them having emerged about the end of April. The male is easily 

 distinguished from the female (even on the wing) by the patch of 

 pure white hairs on the dorsal surface of the end of the abdo- 

 men ; the total length of the fly is about one inch, and the 5 is 

 usually the larger. When about to couple — the § generally sit- 

 ting quietly on a leaf or twig — the S hovers for a few moments 

 like a SyrpJiid, about a foot above and a little in front of and facing 

 the 5 . He then suddenly darts down on her, and coupling is 

 immediately effected. They, remain in coitu several hours, end to 

 end, the $ often feeding meanwhile, as is the habit of the Asilidce. 

 There are one or two smaller species in Kwangtung, probably of 

 the. same genus, which construct similar but smaller egg-cases. 



The species here noted was observed making its ootheca in the 

 middle of May, on the underside of a stout tendril of a shrub 

 about four feet from the ground. The insect hung on the under- 

 side of the twig and curved the tip of the abdomen (Plate A, fig. 1), 

 emitting a whitish, waxy-looking coUeterial fluid and moving the 



The fly is perhaps imdescribed ; it is not yet in the collection of the British 

 Museum, to which, however, the specimens alluded to in this paper will be 

 presented. The male has a conspicuous white tixft on the dorsum just before 

 the genitalia ; the legs are black, except the yellow tibise. This character 

 distinguishes the species from P. yessonicus. Though this is a most ordinary 

 looking Asilid and appears to be very common, there is nothing' very near to it 

 in the British Museum collection. — D. Sharp. 



