GRAPE PESTS 5 



Adult 



The moth is light brown with numerous dark brown spots on the abdomen, at 

 the joints of the legs, and near the tips of the forewings. The forewings are 

 divided into two parts with the cleft extending from the outer margin about 1/3 

 the length of the wings. The two upper plumes of the hindwings are chocolate 

 brown with a lighter fringe and the lower plume is light brown with a dark brown 

 tuft near the tip. The hindwings are divided into three parts, with the cleft 

 between the upper and middle sections extending inward about one half the 

 length of the wing and the cleft between the middle and lower sections reaching 

 almost to the base. The wing spread is 15 to 18 mm. The legs are conspicuously 

 long and slender, with two pairs of long tibial spurs on the hind legs and one 

 pair on the middle legs. 



LIFE HISTORY AND HABITS 



The moth is not a strong flier and is most active at night. When at rest, the 

 forewings are folded, enclosing the hindwings in a roll which is held at right 

 angles to the body. In this position it often hangs by the front. and middle legs 

 with the body and hind legs perpendicular to the surface. In the insectary cages 

 the average life of the moths was 7.87 days for the males and 11.55 days for the 

 females, and observations in the field indicated that they were relatively short 

 lived. 



Oviposition 



The eggs are laid singly but are frequently deposited in groups of two to ten. 

 They are usually placed in the crevices around the axil of branches on one- or 

 two-year-old canes (Fig. 6). In this location they are embedded in the pubescence 

 on the cane and may not be visible to the naked eye although a small part of the 

 egg is usually exposed. No eggs have been found directly on the current season's 

 growth although they ma}' be at the base of a new cane. 



In the insectary one female moth laid 21 eggs in 4 days but the average number 

 of eggs per female was 12.67. On caged potted vines, Concord and Delaware 

 were equally attractive for oviposition but very few eggs were laid on Niagara. 



An examination of 102 infested nodes from a normally infested vine showed 

 an average of 3.19 eggs per node or bud; but since no eggs are laid on the current 

 season's growth, only about 8 percent of the nodes on all of the canes were in- 

 fested. 



Incubation 



Incubation begins soon after the eggs are laid and the developing larva is 

 visible through the eggshell in 10 to 14 days. However, the larva remains in 

 the eggshell throughout the winter and the average time spent as an egg is 320 

 days or slightly more than 10 months. 



Growth of Larva 



When first hatched, the small larvae crawl into the swelling bud and feed 

 slightly on the unfolding leaves. As the shoot grows, the caterpillar fastens one 

 or more terminal leaves together with silk and lives within the shelter thus formed. 

 The average life of the larva is about 5 weeks, varying slightly with the season. 



