308 BOARD OF AGRICULTURE. [Pub. Doc. 



tics : one in Arlington and the other in Swampscott. They 

 were not discovered in those places until they were far advanced 

 in the work of defoliating the trees. In Swampscott they 

 stripped the foliage from both evergreen and deciduous trees 

 of all species, and even ate portions of the twigs. They did 

 this in the face of prompt and vigorous measures which were 

 taken to check their ravages. Fire was used as a last resort. 

 They destroyed the foliage of shrubs, vines and all growing vege- 

 tation, even attacking the herds-grass in the fields. They spread 

 over ten acres of woodland, and stripped a large part of it before 

 they were checked. It is said that in Medford they destroyed all 

 the foliage in many orchards in some previous seasons, although 

 the owners did all in their power to stop them. From the evidence 

 of trustworthy residents it would seem that the gypsy moth, where 

 abundant, moves like the army worm, destroying all vegetation 

 as it goes. 



Obstacles to Extermination. 



There are many circumstances connected with the life-history of 

 this insect which must be taken into consideration in planning for 

 its destruction. Such of these as directly and materially affect 

 our plans are given below, with their bearing on the question of 

 extermination : — 



1 . The enormous increase. The female lays a large number of 

 eggs. These eggs are protected by a covering composed of hairs 

 from the body of the female, and are usually deposited in sheltered 

 situations. Under favorable conditions nearly all the eggs hatch, 

 and, as the young caterpillars are very tenacious of life, a large 

 proportion come to maturity. 



•>. Where abundant, it is found on nearly all plants of economic 

 importance, whereas many other insects confine themselves to a 

 few plants. 



3. The long season during which it feeds. The eggs hatch from 

 April to the last of June, and the caterpillars feed during 

 May, June, July and August. If one crop of caterpillars be 

 destroyed, another will follow, and the entire infested district 

 must be gone over again and again, while the men are engaged in 

 spraying, or destroying the caterpillars by other means. 



4. The wandering habits of the caterpillars. In thickly infested 

 regions, wherever the trees become overcrowded and much effort 

 is required to find food, many of them become restless, and 

 wander in all directions. At such times the slightest disturbance 

 will canst 1 them to spin or drop down from the branches and attach 

 themselves to moving objects. They are thus carried to a distance. 



5. The most, densely infested areas correspond nearly with the 



