SHADE TREE INSECTS 9 



Life History. Most of the eggs are laid during July or earl>- August on the 

 trunks and branches of trees, where they may be found on the open bark surface, 

 in crevices and cavities, and under loose bark; or on stone walls, fences, and 

 buildings. The eggs usually hatch the following spring about the time the leaves 

 unfold. 



The caterpillars feed mainly at night and usually seek shelter from the sun 

 during the day. When disturbed, the young caterpillars drop on a silken thread 

 and may be blown by the wind for considerable distances. The larvae molt five 

 or six times, become full grown in late June or early July, and seek out a sheltered 

 place in which to spin their cocoons and pupate. The pupal stage lasts from 10 

 days to 2 weeks, after which the adults emerge. The female moths are heavy 

 bodied and practically flightless so that they usually lay their eggs in the vicinity 

 of the place where they pupated. The male moths are more slender bodied, 

 are strong fliers, and may be found at some distance from areas where the cater- 

 pillars fed and pupated. 



Control. This insect is being combated in several ways. First, a barrier zone 

 about 30 miles wide has been established at the western limits of the infestation 

 to prevent the pest from spreading be>ond its present limits, and all outbreaks 

 found within this area are sought out and eradicated. The zone e.vtends from the 

 Canadian border to Long Island Sound through western New England and east 

 of the Hudson River in New York. In Massachusetts it includes all of Berkshire 

 County and parts of Franklin, Hampden, and Hampshire Counties west of the 

 Connecticut River. In addition to eradication work in the barrier zone, all 

 isolated infestations which originated from independent sources are being cleaned 

 up as rapidly as possible. Second, quarantines have been established to 

 prevent any stages of the insect from being carried out of the heavily infested 

 area, which in Massachusetts at the present time extends close to the eastern 

 border of Berkshire County. Third, control measures are being applied to the 

 insect outbreaks in the infested areas, as follows: 



1. Scouting for egg masses and painting them with creosote. A little lamp- 

 black is mixed with the creosote so that the treated masses maj^ be distinguished 

 from the untreated. Because of the better visibility when the leaves are not on 

 the trees, this work is done to best advantage in the fall, winter, and early spring; 

 but if snow is present the egg masses covered by the snow will be overlooked. 

 They will also be protected from extremely low temperatures so that a larger 

 percentage will survive the winter under the snow than above the snow line. 



2. Spraying foliage in the spring when the leaves become large enough to 

 retain the poison. The spray should be mixed in the proportion of 5 pounds of 

 lead arsenate to 100 gallons of water, with 1)4 pints of raw linseed oil or fish oil 

 added as a sticker. For severe infestations both creosoting and spraying have 

 been found to be essential for satisfactory' control. 



3. Banding the trees. 



a. With burlap during the larval period. A burlap strip about 

 8 inches wide should be wrapped around the trunk, held in place by a cord tied 

 in the center, and the upper half of the band folded down over the lower. During 

 the day the caterpillars seek shelter beneath this burlap. At frequent intervals 

 the strip should be examined and all caterpillars under it crushed. Wherever 

 brown-tail moths are present this method should not be used until after all the 

 brown-tail moth caterpillars have pupated because these caterpillars may crawl 

 under the burlap and, since they are covered with brittle, poisonous hairs, may 

 cause severe irritation to the hands of the workers who examine the strips. 



