100 DECIDUOUS FEUIT INSECTS AND INSECTICIDES. 



it eats its way out at or just above the bottom of the egg- and begins 

 to feed along the under surface of the bark. When first hatched 

 the larvae are slightly longer than the egg but are less in diameter. 

 After emerging from the eggshell they are found lying in a slightly 

 curved position in the larval burrows. At first they are white but 

 soon assume a pinkish tinge due to the bark in the digestive tube. 

 The larva? at first feed slowly and are several days getting away 

 from the eggshell but progress faster as they grow larger. As 

 they work out of the eggshell the sawdustlike excrement passed 

 through the body fills these and holds them in place as the larvae 

 work out. The excrement voided by the larva> marks their path, 

 appearing like very fine sawdust. 



The larva^ work away from the brood chambers at right angles, 

 following, for the most part, the grain of the wood. For from one- 

 half to three-fourths of an inch the larval burrows lie side by side, 

 but later they diverge, so that the exit holes (PI. X, fig. '2) form an 

 irregular ellipse around the brood chamber. The larval burrows 

 measure from l-J- to 2| inches in length. When about to pupate in 

 bark, which is about one-eighth of an inch or more in thickness, the 

 larvae work toward the outer edge of the bark and there form pupal 

 cells. In these cells the larva^ continue to develop from one to three 

 or more clays before casting the skin and becoming pupa:*. 



Some 25 to 30 days are required for the full development of the 

 larvae. At the end of this time, having finished feeding, they void 

 the excrement before pupating and have then a white appearance. 

 Through the life of the larvae the head is covered with a fine yellow- 

 ish pubescence, which is more abundant about the mouth parts than 

 elsewhere. (Full-grown larva, fig. 20, d.) 



Description of fiill-gn/ini larva. — Length, 2.15-2.75 mm.; widtb across thorax 

 (widest part of insect), about 1.16 mm. Head subelliptical, about 0.6 mm. wide, 

 yellowish, apex lighter; mandibles brownish, dark at tip. Body white, curved, 

 tapering from tliorax to i-ounded caudal end, quite wrinkled; legless, hut on 

 ventral surface of thoracic segments a small group of setie at points of position 

 of the adult's legs. Head with a few si)arse setjie and a few on body. Body 

 covered all over with many minute, short, stout spines. 



THE PUPA. 



The i:)Ui)ae (fig. 20, e) are quite active, moving the abdomen con- 

 tinuall}^ back and forth. From 4 to 10 days are spent in the pupal 

 stage, the pupa gradually assuming a dark color. AMien the pupal 

 skin is cast, the beetles are very tender; they require from 4 to G days 

 to completely harden and usually do not cut their way out from the 

 pupal cells until they have fed a little, after which the}'^ remain in 

 the pupal cells for from several days to two weeks longer. 



