224 INTERNATIONAL CONGRESS OF VITICULTURE 



larvae spin their cocoons before many of the leaves fall. They drop to the 

 ground, or let themselves down by silken threads, often falling with the 

 berry in which they are feeding. These larvae then seek some leaf anchored 

 in the soil, or lodged in the mud; cut the tiny flap and spin a thin white 

 silken cocoon, inside of which they transform to pupae. Here they pass the 

 winter as pupae, and emerge as moths the following June. 



The habits of the larvae are distinctive and characteristic of this 

 insect. The dark olive-greenish or bluish-black larvae are very active when 

 disturbed. The individuals of the last brood of larvae will wiggle out of a 

 bunch, if disturbed, and lower themselves rapidly to the ground, on a silken 

 thread. When found in a berry, they will often crawl out and escape capture. 

 The larva, in spinning a cocoon, usually draws over the edge of the leaf and 

 makes a folded pocket inside of which it spins its cocoon. Sometimes it cuts 

 a flap out of the central part of a leaf, but this is not the most common way. 

 These cocoons usually break out of the dried leaf during the fall or winter 

 and lay on the ground until they transform into moths the following June. 



In no case could the larvae be induced to spin upon grass or other leaves 

 than grape leaves, when they were introduced into the breeding cages, but 

 a few spun upon moist newspaper. Many larvae transformed to pupae 

 without spinning a cocoon of any kind and the remainder died without 

 attempting to spin cocoons. The little lilaceous brown moths are very incon- 

 spicuous when at rest on the bark of a grapevine or on dead wood. When 

 disturbed, they fly with a rapid motion of the wings, with a peculiar zig- 

 zagging flight which makes them very hard to follow. They fly low, and 

 usually are most active from 3 : 30 until dusk. Perhaps they are active during 

 the night, but they are very difficult to follow. 



Various methods of control have been tried, but spraying thoroughly 

 with three pounds of arsenate of lead and weak bordeaux mixture to which 

 two pounds of soft soap has been added, is the most effective remedy. Three 

 applications of spray are usually given; one just before the grapes bloom, a 

 second when the grape berries are almost as large as peas, or three to five 

 millimeters in diameter, and a third application in the latter part of July, 

 varying with the season and locality from July 25th to August 6th. Burning 

 all the leaves and trash early in the fall will assist in controlling the berry 

 worm to a limited extent. Gathering all of the leaves, anchored in the soil, 

 in the fall before the frost causes all the leaves to fall, taking care not to 

 allow the cocoons to break out and fall to the ground, putting them in a 

 tight basket and burning them, will help greatly in controlling the berry 

 worm. Plowing fairly deep before the 25th of May will bury many of the 

 cocoons so deep that the moths will never get out. Heavy sprayings with 

 arsenate of lead and soap (the soap makes the spray stick better and helps 

 it to spread around the smooth berries) is the most satisfactory means of 

 control. 



In spraying for the grape berry worm a number of poisons were tried as 

 the most promising remedies arsenate of soda, Paris green and arsenate of 

 lead and during the season of 1910 arsenate of lead in combination with 

 lime-sulphur, which gives largely an arsenous sulphide as the poison. These 

 poisons were used alone, with bordeaux, with soap, with resin soap, and with 

 bordeaux and soap. Arsenate of lead, bordeaux and soap gave the best 

 results in every case, using three pounds arsenate of lead, two pounds copper 



