GRAPEVINE FLEA-BEETLES. 13 



DISTRIBUTION. 



The writer has collected this species in the vicinity of North East 

 and Moorheadville, Pa., and has observed it at Niagara Falls, N. Y. 



FOOD PLANTS. 



The grape (Vitis spp.), both wild and cultivated, and the Virginia 

 creeper (Parthenocissus quinguefolia) are food plants of both the 

 larva and the adult of this beetle. Of the cultivated grapes the 

 larva nourishes on thin-leaved varieties like the Delaware but does 

 not favor thick-leaved sorts like the Concord. Larvae were fre- 

 quently found on Concord grapes in the field but the majority of the 

 newly hatched larvae placed on Concord leaves in cages failed to pass 

 the first instar. After this instar was passed little difficulty was 

 experienced in carrying them to the adult stage. 



Grape growers, mentioned by Slingerland (19), who stated that 

 thin-leaved varieties of grapes were preferred by the grapevine 

 flea-beetle probably had this insect to deal with instead of the typical 

 species. 



HABITS. 



When the adult emerges from hibernation in the spring it attacks 

 grape leaves which are already expanded. On the leaves of favored 

 hosts it feeds on the lower sides, riddling them with holes. (PL IV.) 

 On Concord and other similar varieties it feeds on the upper surface, 

 pitting it with short irregular feeding marks but not eating through 

 the leaf. (PI. Ill, C.) Like the typical species it feeds much more 

 voraciously at this time than later. It also has the same habit of 

 feigning death when alarmed. 



Eggs are usually placed singly on the underside of grape leaves, 

 along the veins. (PL I, C.) Occasionally two or three are together 

 and very rarely they are on the upper surface of the leaves. This 

 is strikingly different from the place of oviposition and arrangement 

 of eggs described by Slingerland (19) and Hartzell (24), but agrees 

 with the records of Comstock (12), Marlatt (18), and others. 



Like the adult the larva usually feeds on the underside of thin- 

 leaved varieties of grapes and the Virginia creeper. A newly hatched 

 larva usually begins at the side of a leaf vein and bores upward. 

 When leaves are first attacked a series of small holes appears along 

 the leaf veins, producing a characteristic marking which need not be 

 mistaken for the feeding injury of any other insect. (PL IV.) After 

 feeding has progressed for some time the holes are larger and are 

 scattered over the leaf, which may become entirely skeletonized. 

 The larvae do not move readily from one leaf to another and conse- 

 quently the leaves on one part of the vine may be completely riddled 

 while those near by are untouched. 



