3t) DECIDUOUS FRUIT INSECTS AND INSECTICIDES, 



pressed and concave, the hollow being oval and following the out- 

 line of the margins; the bottom side or base is flat. The surface is 

 rough and sculptured into irregular polygons with from three to six 

 sides. The eggs are adhesive, hard, visible to the naked eye, but 

 minute, measuring 0.G3 by 0.38 mm., and are deposited singly. They 

 differ in aspect from those of the peach borer, and also are usually 

 lighter in color and not as large and stout. They are rather more 

 difficult to find in nature. 



At present the length of the period of incubation is not well known. 

 Mr. Quaintance records it as 7^ days in the month of September, 

 latitude of Washing-ton, D. C. Upon hatching, the little larva 

 cuts its way through the anterior end of the egg, leaving quite a 

 large exit hole in the egg shell, which retains its shape and place 

 until it weathers off. 



The eggs were first observed in nature by Bailey (18T9) ; he found 

 a cluster of them on the under surface of loosened plum bark, about 

 6 inches above the roots. Usually, however, they are deposited 

 singly along the trunk of the tree, being placed in crevices, openings, 

 or roughened places. Sometimes a few are placed on the ground or 

 high up in the tree on tAvigs or leaves, but the majority are de- 

 posited on the main trunk of the trees. The number deposited by 

 a single female is unknown. Moths kept in confinement refuse to 

 mate, and the female deposits few eggs or none at all. To determine 

 the number resort is therefore made to dissection. Mr. Quaintance 

 dissected two fertile females after death, and found 305 perfect eggs 

 in one and 296 in the other, in addition to numbers of small unde- 

 veloped ones. Each moth had deposited a few eggs before dying, 

 which Avere included in the count. Dissection of the ovaries of a 

 sterile moth yielded but 58 perfect eggs, but there were present 

 many undeveloped ones. Until more dissections are made the evi- 

 dence on this point remains inconclusive. 



77/c larva. — Allien the larva hatches it is very small, and especially 

 hard to detect with the naked eye because of its dull white color. It 

 is an ordinary caterpillar, bearing the usual seta> and number of pro- 

 legs, and in its earlier stages is almost indistinguishable from the 

 young larva; of the peach borer. However, after molting once or 

 twice it acquires a different asj^ect, which together with a more 

 pinkish and translucent color makes it somewhat more distinct. 

 Throughout all its life it remains alM)ut the same color — various 

 shades of creamy white — and lives concealed under the bark. The 

 following is a description of a full-grown larva, or instar VI: 



Length, 20..5 nun., .-ivernse. (Jreatost width, :'>.4 nnn. Width of head, 1.04 

 nnn., averaj^o. Normal for the family: Hody soiled cream color, innnacxilate, 

 with the usual more or less generalized characters. Head yellowish brown. 



