336 Mr. G. A. K. Marsliall on 



Colonel Biugbam has sent nie the following notes of his 

 observations on AsUidiv : " With regard to flies of the 

 family Asilichv and spiders attacking butterflies, I find 

 only a very few scattered notices of cases which I had 

 seen, but no details, I am sorry to say. So far as I can 

 remember I have seen these flies once or twice actually 

 capture butterflies, and in one instance I find it noted in 

 my diary that I found an Asilus with a Junonia hierta 

 which was still slightly quivering its wings. I have seen 

 the flies not once, but often swoop at butterflies, dragon- 

 flies, and bees. I cannot, however, find any particular 

 note of that case of the Asilus with a dragon-fly the 

 specimens of which are in the British Museum. What 

 note I made was written on the paper envelope in which 

 the specimens had been put away. With regard to the 

 Asilus which I found attacking the dammar bees (Ileli- 

 pona), I find that I have noted that they, the flies, persist- 

 ently hover round the nest-mouth of the dammar bees, and 

 catch the latter on the wing as they issue from the nest. 

 The flies, so far as I have noticed, never eat their prey on 

 the wing, but retire to a bush holding their prey with 

 their long hairy legs." 



A study of the table at once shows that the Asilid^ are 

 most indiscriminate in their attacks. The stings of the 

 Aculeates, the distasteful qualities of Danaina} and Aow- 

 iutV and of the odoriferous Lagria, the hard chitinous 

 covering of Coleoptera, the aggressive j^owers of Odonata, 

 are alike insufficient protection against these active and 

 voracious flies. The only tendency towards specialization 

 in the direction of any particular group of prey appears to 

 be manifested in the preference of the slender Asilids of 

 the genus Diodria for Ichneumonids.* The far greater 

 frequency with which the female Asilid has been observed 

 with prey is sufficiently accounted for by the larger size of 

 this sex and the more important part borne by it in 

 reproduction. 



Looking at the table as a whole, and the large propor- 

 tion of attacks made upo]i specially-defended insects, the 



* Since this sentence was written I have captured (July 1902) 

 many specimens of Dusypogon diadema with prey at La Granja, 

 Sierra Guadarrania, Spain. The great majority of these were 

 sucking Aculeates, especially tlie hive-bee. Another species of 

 Asilid, on Peiialara, also exhibited an apparent preference for 

 Coleoptera. — E. B. P. 



