THE GRAPE-BERRY MOTH. 23 



cage. Their position could be located only after an extended and 

 careful search, so closely did their coloration harmonize with the 

 background upon which they were at rest. Toward evening they 

 became active, flying about the rearing cage and among the foliage of 

 the vine, and at this time of day oviposition on the blossom clusters 

 and berries doubtless occurs. At no time, however, were the females 

 observed in the act of ovipositing. Practically all of the egg deposi- 

 tion on grape berries in the rearing cages occurred at night; hence 

 there is no doubt that the moth is largely nocturnal in its activities. 

 It has been observed quite frequently, however, that in the vine- 

 yards egg deposition is much heavier upon the grape clusters that are 

 enveloped in dense foliage. This would indicate that conditions of 

 subdued light are more favorable to oviposition than are exposed 

 positions. 



HABITS AND CHARACTER OF INJURY OF THE LARVA. 



It is in the larval or caterpillar stage that this insect is injurious 

 to the grape, and, as the popular name of the insect indicates, the 

 berry or fruit is the part of the plant which it attacks. In 1868 

 Packard recorded the larva as feeding on the leaves, but the next 

 year he corrected this error, and later observations by entomologists 

 have failed to confirm this habit. The first larvae to hatch are from 

 eggs which are laid by the earliest emerging moths in spring and are 

 doubtless deposited on the unexpanded blossom buds or on the stems of 

 the blossom clusters. These larvae attack the blossoms and the tiny 

 berries. In the course of its movements, which must cover the entire 

 blossom cluster, the larva spins a silken web. This web binds to each 

 other and to the stem the dried corollas, stamens, and partly devoured 

 berries, forming a conspicuous mass (see fig. 5). Usually, however, 

 these webs formed during the blossoming period of the grape are 

 not very numerous except in those portions of vineyards where 

 the infestation is very heavy. In addition to attacking the blos- 

 soms and small berries of the young grape clusters the larva some- 

 times burrows into the stem, destroying a part of the cluster (see 

 PI. V, fig. 1). As the berries increase in size the small, scale-like, 

 semitransparent eggs are readily found upon them. The portion of 

 the berry at which the larva enters takes on a conspicuous purple 

 color, and not infrequently the infested berries crack open as illus- 

 trated in Plate V, figure 2. In addition to destroying the berry 

 first attacked, the larva connects it to an adjacent berry by silken 

 strands, forming a tunnel between the partly injured berry and the 

 sound one. This forms an avenue of escape for the larva when the 

 berry first attacked is so badly injured that it breaks away from the 

 stem (see PL V, fig. 2). When the larvae of the first brood have 



