104 MISCELLANEOT^S PAPERS. 



and siuTouiids the anal end of the body. Attached to the leaf or stem 

 by this base, the maggot (see fig. 27) is able to reach out in all direc- 

 tions as far as its length will permit — and it is mnch more slender and 

 elongate than those maggots which hatch from deposited eggs. It is 

 constantly in motion when it feels the proximity of a host. As the 

 maggot is deposited on the silken thread with which a w^ebAvorm or 

 caterpillar of Euproctis chrysory'hoea marks its trail as it leaA'es the 

 nest, the caterpillar is sure to pick it np in following its thread back. 

 Doubtless the flies larviposit only on freshly laid strands, which have 

 not lost the odor of the caterpillar. When the maggot is left undis- 

 turbed for a time it appresses its body longitudinally to the surface of 

 the stem or leaf-rib to which it is attached. But the moment it is 

 touched by any object it immediately becomes extremely active, striv- 

 ing to attach itself to the looked-for host. As soon as it lays hold on 

 a caterpillar tlie motion of the latter and the exertions of the maggot 

 itself pull it loose from the membranous cup-shaped base, which re- 

 mains where it was attached. 



It is probable that this halut of larviposition in Eupeleteria tnagru- 

 cor'nls has been developed on account of the advantage gained thereby 

 in the certainty of attachment of the maggot to a caterpillar. Being 

 deposited where the caterpillar must pass over it, the maggot can 

 attach itself with great ease to the legs or miderside of the caterj^illar. 

 where the hairs are few and short. It would be much less certain of 

 attachment if the female attempted to deposit it directly on the 

 caterpillar. The fly is large and would unduly alarm the caterpillar, 

 which would make frantic efforts to shake the maggot oft'. In this 

 it would often succeed before the maggot could find its way through 

 the barbed hairs that protect the upper and lateral surfaces of the 

 caterpillar's body. 



The maggot of Eupeleteria iiiagnicornis^ as might be expected, in 

 view of its deviation in habit from the maggots of those species pre- 

 viously studied, has the integument quite dift'erent in character, since 

 it must remain for a considerable time outside the host. The species 

 which deposit living maggots on the caterpillars, as well as those 

 which deposit eggs, have a whitish, thin-skinned maggot. The maggot 

 of Tnagnicornis, however, has a tougher skin and is quite dark in color. 

 In the opinion of the writer, it is one of the most specialized tachinid 

 maggots known, although the body shows 13 very distinct segments. 

 The integument, both dorsal and ventral, is furnished with minute, 

 slightly chitinized, scale-like plates, save only the median ventral 

 region. Those of the dorsal region are distinctly larger and more 

 chitinized than are those of the lateral ventral region, but the median 

 ventral surface of each one of the body segments except the anal is 

 entirely without them, being furnished instead with a band of minute 

 black spines, which are entirely lacking on the dorsal surface. Thus 



