1908.] PUBLIC DOCUMENT — No. 33. 153 



conditions where it occurs, and it was found that the limits of 

 its distribution, as already published, though approximately 

 correct, are not entirely so, the insect having been found in one 

 or two directions beyond those limits. In most of the infested 

 territory the brown-tail moth is abundant, and spraying with 

 arsenate of lead was very general in that region last summer. 

 The result was also to destroy large numbers of the larvae of 

 the oriental moth, the treatment being so effective that in Au- 

 gust it was hard to find any of the caterpillars without making 

 a prolonged search. 



These facts indicate that this insect is not likely to become 

 a serious pest. If it should become well established, however, 

 in some locality where no attention is paid to insect pests, it is 

 possible that it might cause considerable injury ; but in such a 

 case it is probable that a single thorough treatment there would 

 be effective for several years. The Japanese name " ira-mushi," 

 for this insect means " the nettle insect," and during the sum- 

 mer several reports of the nettling caused by the spines of the 

 caterpillars were received, indicating that, if this insect should 

 at any time become very abundant in an inhabited locality, the 

 residents there might suffer some inconvenience from its pres- 

 ence. 



Massachusetts is close to the northern limit of the distribu- 

 tion of some insect pests and near the southern limit of others. 

 It seems probable that for some of these there are portions 

 of the State where these pests may be of importance, while in 

 others they will require no attention. It is important that the 

 exact facts in this regard should be determined, and researches 

 have been begun to ascertain the localities in which comparative 

 immunity from certain pests may be expected. To obtain defi- 

 nite results on this subject will be the work of several years 

 and much correspondence, but it is hoped that when they are 

 obtained, directions can be prepared which will guide towns 

 in different localities in making their annual appropriations for 

 the protection of their trees, which will save many thousands 

 of dollars. 



Three bulletins on insects (Nos. 114, 115 and 116) have 

 been published during the year, besides numerous circulars 

 already referred to, these last being used only in answering 



