162 Pecan-Growing 



PECAN LEAF CASE-BEARER (Plate IX) 



(Acrobasis nehulella, Riley) 



The leaf case-bearer is perhaps the most destructive of the 

 insects that attack pecans east of the Mississippi River. It 

 passes the winter in the larval stage and may be found in 

 small bags or casesj singly attached to the buds of the small 

 branches. Soon after the buds swell or start growth in the 

 spring, these small larvae crawl out of their cases and begin 

 feeding on the nearest unfolding buds or tender leaves. They 

 are ravenous feeders and, when the numbers are large, are 

 capable of defoliating the tree almost completely. In eating 

 out the buds and tender twigs, this insect greatly decreases the 

 crop of nuts. Furthermore, defoliation just at this time, 

 when the tree is making its maximum annual growth, weakens 

 it to such an extent that many of the limbs die back a con- 

 siderable distance from the terminals. 



The larva or ^^worm" of the pecan leaf case-bearer feeds 

 voraciously and grows rapidly after the opening of spring 

 and pupates in the case from the latter par^t of. May until 

 the first or second week in June, according to climatic condi- 

 tions. The pupal state lasts from sixteen to twenty-three 

 days, at which time the adult moth emerges and soon begins 

 to lay eggs. 



The egg-laying period of the moth extends from the latter 

 half of May until about the first of August. From one to 

 twenty eggs may be laid on a single leaf. These eggs are 

 small, soft, and semi-transparent objects, usually attached 

 along the midrib on the under side of the leaflets. The eggs 

 hatch from six to nine days later and the larvae, when first 

 emerging, are reddish-brown in color. They begin feeding 



