OF WASHINGTON, VOLUME XIII, 1911. 149 



A NOTE ON ASCODIPTERON. 



(Diptera.) 



PLATE XIII. 



BY NATHAN BANKS. 



Recently Dr. Lyons, of the Department of Mammalogy of 

 the U. S. National Museum, while examining Bornean bats of 

 the genus Emballonura, came across some peculiar swellings 

 on the body, which he concluded were insects, and brought 

 them to the Section of Insects. These somewhat pear-shaped 

 bodies were in a cavity of the skin of the bat, with the anal 

 end of the body extruded. An examination of these speci- 

 mens disclosed a head and thorax of very peculiar appear- 

 ance, retracted within the sac-like body. 



A survey of the literature showed that they belonged to the 

 genus Ascodipteron, described in 1896 by Adeusamer. The 

 structure of the sternum places these forms as belonging to 

 the Streblidae. Now we learn that Muir has bred them and 

 found that the winged specimens, male and female, are 

 Streblidas. He says that the female after mating breaks off 

 her wings and legs and burrows into the skin of the bat, leav- 

 ing only the anal end extruded. This agrees with what we 

 have found all six legs present, but of only two joints, the 

 second with a black apical scar where the rest of leg was 

 broken off. Monticelli in his figures shows the stumps of the 

 wings, but did not recogni/e them. Monticelli's family 

 Ascodipteridse is thus a synonym of the Streblidse. 



There are now at least six lots of these creatures known. 

 The one specimen! upon which Adensamer formed the genus, 

 from a Phyllorhina from Java; the Monticelli specimens from 

 Rkinolophus from Abyssinia, Asc. lophotes; the two species 

 described by Speiser, one from Siam, the other from Mada- 

 gascar; the Muir specimens, upon which he has worked out 

 the life history; and finally those taken on Emballoinira from 

 Borneo, shown here. 



The winged Streblidae are very rare; they have been taken 

 in several cases from the same bats that harbor the Ascodip- 

 teron. It is therefore probable that Ascodipteron is but a 

 stage in the life-history of most, if not all, Streblidse, and that 

 our form and Adensamer's species belong to Xvctcribosca. 



The species so beautifully figured by Monticelli is very dif- 

 ferent from that of Adensamer and the one shown here. The 

 body is much more slender; the tip of the abdomen has the 

 spiracles arranged differently; the mouth-armature is different, 

 and the mesosternal sclerites are quite differently shaped, so 



