REPORT OF COMMITTEE ON PUBLICATION 203 



ing: apple, plum, pear, peach, beech (Fagus grandifolia), American elm, 

 sugar maple (Acer saccharum), elder (Sambucus canadensis), raspberry 

 (black and red), blackberry, strawberry, red osier (Cornus stolonifera), 

 Crategus spp., birch (Betulaleadlsnta), willow (Salix alba), ash (Fraxinus 

 americana), sumac (Rhus typhina), common chickweed, Virginia creeper, 

 dog tooth violet (Erytbronium americanum), and dandelion. The only 

 food plants found during five seasons have been the Concord grape and the 

 wild blue grape (Vitis bicolor). The beetles prefer the Concord during the 

 spring but during late summer and autumn feed almost entirely on the 

 foliage of the wild blue grape. Vitis riparia and V. cinerea are rather rare 

 in this region (Chautauqua Co., N. Y.) and the beetles have not been found 

 on them, but this does not mean that these insects do not use these species 

 for food plants. On the other hand, we believe that it means that the 

 locality in which these two species were found was not infested at the 

 times the observations were made for not all localities in which the wild 

 blue grape grows have been found to be infested. 



In the literature mention is made of the following food plants: wild and 

 cultivated species and varieties of grapes (species or varieties seldom given), 

 apple, pear, plum, peach, quince, blue or water beech, elm, and Virginia 

 creeper. The black alder is mentioned but the evidence points to this as an 

 error of mistaking Haltica bimarginata for H. chalybea. The elm has been 

 reported as a food plant a number of times but it appears that where grapes 

 are abundant the elm is not preferred. 



Feeding Habits. 



The flea-beetle attacks the vine during three periods of the insect's life, 

 viz., during June and July as a larva, during August and September after 

 emerging from the pupal stage and during April, May and June after hiber- 

 nating. The larvae, soon after hatching, eat the soft tissues on the upper 

 sides of the leaves, chiefly feeding to the fine network of veins which they 

 leave intact (Fig. 1). This area is always irregular and soon turns brown, 

 giving the leaves a scorched appearance when seen at a short distance. The 

 larvae may be found feeding from near June 15th until about July 20th. 



The adults upon emerging from the pupal cells may eat sparsley the 

 leaves of cultivated grapes but generally fly to nearby woodland and there 

 feed on the leaves of wild grapes although the amount of food used is very 

 small. At this time the adults are difficult to find, owing, no doubt, to the 

 rather extensive area in which the wild grape grows and also to the lessened 

 activity of the beetles. The writer holds the view that the greater heat and 

 lower humidity of the vineyards is a factor in this movement of the beetles 

 to the woodland where the heat is less and the humidity is higher. What- 

 ever the cause, these beetles disappear as if by magic and are seldom seen 

 by the vineyardist until the following spring. 



Although the beetles may be lacking in voraciousness in the fall, this 

 tendency disappears in the spring upon the return of warm weather. They 

 feed almost continuously after their long winter's sleep, especially during the 

 first few weeks after emergence from hibernation. It is at this time they do 

 their greatest damage to cultivated vineyards for, after passing the winter 

 in the waste and woodland, there is a general tendency to disperse after 



