92 DEPARTMENT OF AGRICULTURE. [Pub. Doc. 



in August they resumed their work to some extent. Cucumber 

 beetles (Diahrotica vittata Fab.) were also plenty and did much 

 damage. The Colorado potato beetle (Leptinotarsa decimlin- 

 eata Say), though abundant in some parts of the State, was 

 not serious in general, but the three-lined potato beetle {Lema 

 trilineata Oliv.), which is rarely noticed in most years, was 

 unusually plentiful. 



In 1917 the potato plant louse {Macrosiphum solanifolii 

 Ashm.) was extremely abundant, and in many parts of the 

 State caused much loss. This year it reappeared about ten 

 days earlier than last year, and its work was practically at 

 an end early in August. It was very abundant in many 

 places, though frequently of two fields quite near, one would 

 be nearly destroyed while the other was practically untouched. 

 Parasites were generally numerous and rendered good service. 



About the first of August reports began to arrive of the 

 defoliation of beech, maple and other trees in western Massa- 

 chusetts, and an investigation was made. The insect con- 

 cerned proved to be the Saddled Prominent {Heterocampa 

 guttivitta Walker), which had been very abundant over much 

 of the same territory the previous year. From reports re- 

 ceived and visits made, the work of this insect appears to have 

 extended about as far north as Brattleboro, Vermont, and 

 to have extended southward through the hill towns of Franklin 

 and Hampshire counties west of the Connecticut River about 

 as far as Chester and Becket, and was also in evidence in a 

 few of the towns in the eastern part of Berkshire County. 

 It was very noticeable that the defoliation was almost exclu- 

 sively on the hilltops, the valleys being practically untouched, 

 while thousands of acres of woodland on the higher elevations 

 were entirely stripped. 



Beech and maple appeared to be the preferred food plants, 

 but others were eaten where these species failed to furnish 

 sufficient food for the caterpillars, and in many places only 

 evergreens and the moosewood (Acer pennsyhanicum L.) 

 retained any foliage. These, however, were absolutely un- 

 touched, no matter how famished the caterpillars were. In 

 several cases apple orchards near woodlots where the cater- 

 pillars were abundant were also attacked and stripped. 



