INSECTS INJURIOUS TO THE GRAPE 



457 



The adult hoppers are about one-eighth inch long and the 

 wings are prettily marked with yellow and red as shown in Fig. 

 382. "In summer the young and adult insects are light yellow- 

 ish in color, but before going into hibernation, the eyes of the 

 adults darken and the peculiar yellow spots on the wings change 

 to an orange red, thus giving the hibernating adults a general 

 reddish appearance. These darker markings on the adults vary 

 so much that nine different varieties are now recognized, two of 

 which are represented at b and c, in Fig. 382. Often several 



FIG. 382. Grape leaf-hopper (Typhlocyba comes): a, adult female; 6, adult 

 male; c, another form of the species, showing variation in markings; 

 d, newly-hatched nymph; e, last stage nymph; /, appearance of injured 

 leaf; g, cast pupa skins a, e, much enlarged; g, less enlarged;/, reduced. 

 (From Marlatt, U. S. Dept. Agr.) 



of the varieties may be found together on the same vines, but 

 usually one color form largely predominates." The nymphs are 

 a light yellowish-green color with lemon-yellow stripes on each 

 side of the body. They pass through five molts before becoming 

 adults, the wing-pads gradually getting larger in the later stages. 

 No very similar insects are common on the grape, so that the 

 pest is readily recognized. 



Life History. The adult hoppers hibernate over winter under 

 leaves, grass, or trash in or near the vineyard, in neighboring 

 woods, along ditches or fences, etc. They emerge about May 1 

 in New York and at first feed on whatever succulent foliage may 

 be available. By the time the grape foliage appears they have 



