60 FRUIT INSECTS 



pears also, it is the yellow-headed cran})erry worm, a destructive 

 pest of cranl)erry bogs (see page 462). 



There are three generations or broods of this insect annually 

 on apple in the latitude of Missouri, but it is two-brooded in the 

 cranberry bogs of Massachusetts. The moths are dimorphic ; 

 those of the one or two summer broods have bright, orange- 

 colored front wings, while those of the autumn brood have slaty- 

 gray front wings, often with a dusting of orange scales. The 

 moths have a Aving expanse of about | of an inch. The third or 

 dimorphic brood, bearing the varietal name of Cinderella, appear 

 in September and October, and hibernate in sheltered places. 

 In the spring these gray moths emerge from their winter quarters 

 and lay their minute, disk-like yellow eggs on the unfolding 

 young l(\aves. Two or three broods of the caterpillars fold the 

 leaves during the growing season, the first working in May, the 

 second in July, and the third brood, where it occurs, works in 

 August or September. 



A single folded apple leaf usually furnishers sufficient food for a 

 caterpillar. After feeding for 3 or 4 weeks, it spins a delicate, 

 silken w(rl) or cocoon within tlur k^af, and then transforms to a 

 small brown pupa about \ of an inch long, and chara(;teriz(rd 

 by a curious knob-like })roj(M*tion from tlnr front of the head. 

 In a w(H^k or ten days tlu^se pupie work tlurir way about half out 

 of the foldcnl knaves, and the moths (^merge. 



This apple l(\af-folder has many parasitic; (rnemicrs which are 

 often eff(H'tive nids in restricting its injuries. A Tachina-fly 

 and several hymenopterous parasites an^ known to prcry upon 

 the cat(irpillars, and in Michigan a Hock of l)irds, pro})ably th(r 

 rusty grackle, have Ixurn seen destroying many of the pupa^, 

 neatly picking them out of the folded leaves. 



Remedial measures. 



It is often practicable in nurseries and young orchards to 

 employ men or boys to go through and pinch the folded leaves, 

 thus destroying the caterpillars within. This should be done 



