292 INSECTS AFFECTING VEGETATION 



caterpillars do not emerge till the next spring. A case is on record 

 of eggs hatching in early September, 1895, at Woburn, Mass., but 

 the round of life was not completed, and in this northern latitude 

 at least, there need be little fear of two generations annually. 



The insect feeds upon the foliage of practically all of the shrubs 

 and plants grown for economic and ornamental purposes. Con- 

 cerning recommendations for combating this pest, Dr. Felt has the 

 following to say: Investigate anything that arouses a suspicion 

 that it may be the gypsy moth, but be in no undue haste to identify 

 the insect. It will be much more satisfactory to submit the speci- 

 mens to an entomologist than to arouse unnecessary fears. There 

 have already been several false alarms occasioned by persons with 

 more enthusiasm than discretion, who have attempted to identify 

 an insect with which they were unacquainted. 



It would undoubtedly pay to exterminate a small colony, but 

 in the course of time this will be impracticable. We must learn to 

 control it on our own land. The inability of the female to fly and 

 the conspicuousness of the egg-masses make this task relatively 

 easy, unless the pest is allowed to escape to the woods. There, a 

 private individual could hardly cope with the insect. The point of 

 establishment is almost bound to be near some dwelling, and there- 

 fore the species need not be allowed to establish itself in wild land, at 

 least for some years. 



One of the most effective methods of keeping this pest under 

 control is the careful collection and burning of the conspicuous egg- 

 masses. This can be done most effectually in the fall, during the 

 winter and in early spring. No ordinary fire running over the 

 ground can be relied on to kill the eggs. The only safe way is to 

 put them in a stove or similar fire and burn them. Creosote oil 

 applied to the egg-mass will soak in and kill the eggs. The follow- 

 ing preparation was used in the work against the gypsy moth: 

 Creosote oil, 50 per cent. ; carbolic acid, 10 per cent. ; spirits of tur- 

 pentine, 20 per cent., and 10 per cent of coal tar. The latter was 

 added to color the compound and thus show at a glance what clus- 

 ters had been treated. 



The caterpillars prefer to hide during the daytime, and advan- 

 tage may be taken of this habit to tie burlap bands in the middle 

 around the tree trunks and then turn the upper portion of the bur- 

 lap down over the string. The bands can be lifted daily and the 

 caterpillars beneath killed. This method proved of such great 

 value in the work against the gypsy moth that thousands of trees 

 were banded during the latter part of the caterpillar season. 



The larva is quite resistant to arsenical poisons, and it requires 

 a large dose to kill it, especially when the caterpillar is nearly 

 grown. There is probably no better poison for this pest than 

 arsenate of lead, using at least 5 pounds to every 50 gallons. The 

 application should be made as soon as the leaves are well grown, and 

 then the caterpillars will be poisoned while young and most sus- 

 ceptible to the insecticide. 



