GRAPEVINE FLEA-BEETLES. I 



HABITS. 



The beetle emerges from hibernation in the spring at the time of 

 the swelling of the grape buds, which it attacks voraciously, boring 

 into the sides of the buds and eating out the tender parts. (PL I, B.) 

 When the shoots begin to expand it eats large holes in the leaves 

 (PL III, A), and often attacks the tender stems. The beetle is most 

 voracious when newly emerged from hibernation and at that time 

 can do an immense amount of damage. 



Eggs are usually deposited on their sides, in groups, under bud 

 scales or strips of bark, as described by Slingerland (19) and Hart- 

 zell (23 and 24). Occasionally they are placed on leaves on either 

 the upper or the lower side. 



The larvae feed on either the upper or lower surface of thin-leaved 

 varieties of cultivated and wild grapes, eating out large irregular 

 holes, and often stripping out all of the leaf tissue except the leaf 

 veins. On Concord or similar types of leaves they feed on the upper 

 surface, leaving as feeding marks long, chain-like, whitish patches 

 (PL III, B). 



During the feeding period the larva molts twice. Upon becoming 

 fully fed it burrows into the ground and forms a pupal cell a fraction 

 of an inch below the surface. A few days are passed in the pupal 

 cell, the prepupal period, preparatory for pupation. At the close of the 

 pupal stage, after eclosion, the adult does not emerge at once, but 

 remains in the cell until it is hardened and fully colored. Following 

 emergence the beetle feeds sparingly until it goes into winter quar- 

 ters. None of the specimens under observation during either season 

 showed any tendency to copulate or oviposit during the period be- 

 tween transformation to the adult stage and hibernation. 1 



All stages of the beetles' activity are greatly influenced by changes 

 in temperature. Both adults and larva? feed more voraciously on 

 warm days than in cold weather and on the cold days of early spring 

 the beetles even appear to return to winter quarters. Hatching of 

 eggs and molting of larva? occur in the greatest numbers during the 

 warmest part of the day. 



LIFE HISTORY. 



REARING METHODS. 



The rearing methods used for the two species of flea-beetles were 

 practically identical. Oviposition was secured from adults kept in 

 battery jars or sleeve cages on grape shoots. Larva? were reared in 



1 In addition to the insects native to the Erie-Chautauqua grape belt, upon which the foregoing account 

 of habits and seasonal history and the following of life history are based, the writer received beetles from 

 French Creek, W. Va., collected by Mr. Fred E. Brooks, and from Arlington, Va., collected by Mr. E. R. 

 Selkregg, during the spring of 1917. These beetles and their offspring were reared in the insectary at North 

 East, Pa., and their habits, seasonal history, and transformations agreed in detail with those of the native 

 insects recorded herein. 



