78 



These caterpillars have attacked nearly all kinds of deciduous trees, 

 causing special damage to shade trees like the elm and maple. Many 

 sugar orchards have sustained injury that will interfere with their pro- 

 ductiveness in the immediate future. The attack appears to have been 

 more severe in the villages than in the country. 



The disstria .caterpillars hatch a week or more later than do those of 

 the americana, and there is considerable variation in the time of hatch- 

 ing within the species itself. In a given region caterpillars of various 

 sizes could easily be found late in May or early in June. They feed on 

 leaves in all parts of the tree, having a preference apparently for the 

 upper branches. They commonly eat out the blade along either side of 

 the midrib, severing the marginal part so that it falls off. These sev- 

 ered portions are to be found abundantly on the ground under the 

 infested .trees. The result of this curious mode of attack is, of course, 

 greatly to increase the amount of damage done for the amount of leaf- 

 age actually consumed. At times of molting the caterpillars collect 

 together in masses on the tree trunk. 



Cocoons are spun for the most part after the middle of June. Many 

 of the caterpillars in the trees inclose their cocoons in leaves, while 

 many make them in the bark, and others on the ground, in any shelter 

 that may be at hand. 



Mr. Perkins discussed this communication and stated that he had much 

 experience with G. disstria, and that it was especially bad on the west 

 slope of the Green Mountains, affecting chiefly the sugar-maple groves. 

 It was less troublesome on the Connecticut Eiver side. Eeferring to 

 the two species, he noted the confusion likely to arise from the not infre- 

 quent occurrence of the two species in the same nest. He confirmed 

 Mr. Weed in the very greatly increased parasitism of the present year, 

 and concurred with him in assigning great value to hand collection of 

 eggs. 



Mr. H. T. Fernald described an unusual habit as noticed by him in 

 Pennsylvania. In a large peach orchard the insect was found on per- 

 haps one tree in ten, and yet did not occur at all in an adjoining apple 

 orchard. 



Mr. Forbush presented the following report: 



RECENT WORK OF THE GIPSY-MOTH COMMITTEE. 



By E. H. Forbush, Maiden, JIass. 

 [Author's abstract.] 



Ever since the gipsy-moth exterini native work was placed under the 

 management of the Massachusetts board of agriculture, the plan of 

 operations has been to work from the outermost limit of the known 

 infested region toward the center. 



Obviously such a method, if properly executed, would best carry out 

 the purpose of the State law; first, for the prevention of the spread, 



