INSECT NOTES. 37 



a small white maggot about 1-3 of an inch in length. The adult 

 is a small two-winged fly with banded wings. It is described 

 in Bulletin No. 35 Me. Agric. Expt. Station. (Lot 766.) 



Drosophila busckii. 



This insect belongs to the same genus as the little yellow flies 

 commonly known as Pomace or fruit flies. It has been bred 

 several times from larva found in potato affected by rot. 

 Apparently only the potatoes with broken skin were attacked, 

 though there were a number of decayed tubers. From this it 

 seems evident that the flies were not responsible in starting the 

 rot. As may be expected this fly in all its stages greatly re- 

 sembles Drosophila ampclophila, the common Pomace fly, de- 

 scribed by Professor Comstock in the Report of the Ento- 

 mologist, Department of Agriculture for '8i-'82. 



The tgg though similar in shape differs from that of D. am- 

 pclophila in having 4 slender and pointed filaments (not blunt) 

 near the micropyle. The larva is elongate oval, about 5-16 of 

 an inch in length when full grown ; the head end more slender 

 and pointed ; the posterior end of the body broadest. The an- 

 tennae are minute tubercles placed on the dorsal surface of the 

 first segment ; the 2 jaw hooks are black in color and each pro- 

 vided with 4 slender teeth of which the third from the base is 

 smallest (fig. 50). Fringing the mouth are a number of 

 minute colorless, recurved hooks only distinctl}^ visible in pro- 

 file. The cephalic spiracles each consist of about 12 tracheal 

 tubes of varying lengths, slightly hooked at the end. These 

 tubes may be extended or retracted within a cylinder which is 

 somewhat longer than wide. The body is covered, though not 

 densely, with erect setulae, and each segment is provided with 

 about 8 spinose protuberances, fewer and longer on the last 2 

 segments where they nearly equal the caudal spiracle in lengtli. 

 The latter consists of 2 coalesced tubes. The pupa, which is 

 about '/s of an inch long, resembles the larvae in having the 

 body sparsely covered with setulae, spinose protuberances, and 

 a caudal spiracle of 2 coalesced tubes. At the head end there 

 is a large concavity, covered by a plate which comes ofl:' when 

 the adult emerges. To this plate are attached the thoracic 

 spiracles, cylindrical processes each terminating in 12 tracheal 



