THE APPLE MAGGOT ; THE LARVA AND THE FLY. ri9 



making therein little rough, roundish, irregular and discolored excava- 

 tions about the size of peas, which, when several of the larvae are at 

 work on the same fruit, often run together, so as to render the whole 

 a mere mass of useless and disgusting corruption." 



The following is Mr. Walsh's description of the larva, which is given 

 entire, as the report in which it is contained has become quite rare, and 

 it has never, to my knowledge, been republished. With the descrij)tion 

 and the larva in hand there should be no difficulty in determining the 

 species whenever the burrowing of the apple, as above described, ren- 

 ders its presence probable : 



It is of a greenish-white color, 0.15, 0.20 inch long, and about four 

 and one-half times as long as wide, cylindrical behind, with the tail-end 

 squarely docked, tapering on front from the middle of 

 the body to the head ; head pointed, but narrowly 

 excavated (emarginate) in front ; its inferior surface 

 wnth two slender, bluntish, coal-black hooks projecting 

 in front, where the mouth is protruded [mouth-joarts, 

 used in feeding, shown in Fig. 25], at the base of 

 which there is a smaller pair connected with the base 

 of the others like the antlers of a buck's horn ; at the 

 base of the first segment, behind the head, a dorso- 

 lateral, transverse, pale-brown, flattish, rough tubercle 

 [one of the spiracles] ; last segment below with two 

 pale-brown, horny, rough tubercles, each composed of 

 three mimite thorns longitudinally arranged ; and 

 , '•''f- 2^.-H.>;vtof the abovc, witli two whitish retractile ones, each i)air of 



larva of Tuvi'Eta pomo- ' ' ^ 



KKi,i,A, in front ami side tubcrclcs transvcrsclv arranged. 



view, showing the ' ^ 



liiouth-parts a'Hi tiie Prof. Comstock, who has made special study of this 



tirst spiracle. (After ' ' -' 



coir.stock.) insect, has given an enlarged figure of the larva {loc. 



cit.). which w^ecopy, somewhat reduced, in Fig. 26 at a, and the follow- 

 ing descriptive features : The larva averages about one-fourth of an 

 inch in length (0.19-0.27 in.), is footless, wdiite with sometimes a yel- 

 lowish or greenish tinge. The anterior third of the body tapers slightly 

 to the head — the latter smaller than any of the segments. The ])os- 

 terior two-thirds of the body is cylindrical, having the end obliquely 

 truncate, bearing upon its slope four pairs of tubercles — one pair more 

 prominent than the other. 



The Fly, 



Trjipeta pomonelhi, in its perfect state, is a pretty fly, shaped not un- 

 like the common house flies that we find upon our windows. The figure 

 given does not present the usual shape of the abdomen in the examples 

 in my collection. In these, it is the broadest quite near the base where 

 the first and second of the four conspicuous white bands should appear, 

 and thence tapers conically to the pointed tip. It may be easily recog- 



