40 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



toward the posterior and free end of the case. The opening at this 

 end is closed by three lobes, which are readily pushed apart by the 

 emerging adult. A day or two after the fastening of the case, pupa- 

 tion takes place, and from ten to twelve days later the adult emerges. 

 At North East, Pa., the first adult emerged June 22; the maximum 

 emergence took place during the early part of July, while after July 

 25 no adults emerged. As a rule, the adults emerge in the afternoon, 

 and for several hours remain motionless on the case in a characteris- 

 tic pose, as shown in figure 4 of Plate II. Toward evening they 

 become restless and fly off. Moths even a few days old generally 

 seek their favorite resting place on the attached cases. 



The eggs are generally laid along the midrib, on the underside of 

 the leaves, where they are found inserted in the pubescence or down 

 of the leaf. A few eggs were similarly found on the hairy branches. 

 The egg period lasts from fifteen to sixteen days. 



The newly hatched larva? are 

 quite active, and were found 

 moving about for several hours 

 before eating their way into the 

 leaves. During their early life 

 they are true miners and feed 

 for about two weeks on the inner 

 tissues of the leaves. Their 

 mines take the form of minute, 

 elliptical, brown patches, and 

 are readily located by the pres- 

 ence of the black powdery ex- 

 crement which the larva? eject 

 from the mines. 



Toward the beginning of 

 August the larva? construct a 

 minute case from the upper and 

 lower skins of the mined area of the leaf. Plate II, figure 1, shows a 

 single leaf from which numerous cases of this kind have been made. 

 Before the foliage is ready to drop, the minute case-bearers migrate 

 to the branches, where they fasten their cases and seal themselves up 

 for the winter. During the latter part of August and early Sep- 

 tember they were found in great numbers, especially in the forks and 

 to some extent on the lower side of the branches. (See PI. II, fig. 2.) 

 For seven months the larva? remain thus concealed in a dormant state, 

 and, as previously stated, do not become active until spring. 



A general idea of the life cycle of the insect may be obtained from 

 the diagram, figure 11. It shows the life cycle of a single insect, the 

 dates and periods shown being averages for the insect as it was ob- 

 served in its various stages in the field. 



Fig. 11. — Life cycle of the cigar case-bearer : 

 Adapted to a single insect under average 

 normal conditons. (Original.) 



