IO REPORT OF THE STATE ENTOMOLOGIST I92I 



The spruce gall aphid, Chermes abietis Linn., continues 

 to attract notice on account of the unsightly galls it produces upon 

 Norway maples. The spruce bud scale, Physokermes 

 p i c e a e Schr., is likewise widely distributed. Evidence obtained 

 the past season indicates that under certain conditions at least this 

 latter insect may be an important factor in killing portions of good- 

 sized trees. 



Forest insects. There was an outbreak of the antlered maple 

 caterpillar, Heterocampa guttivitta Walk., in Chautau- 

 qua county in 1919 accompanied by defoliation of sugar bushes in 

 areas where the insects were most abundant. 



A somewhat extended and serious infestation of the gipsy moth 

 was discovered in New Jersey in July 1920 and was followed 

 shortly by the location of several small, light infestations on Long 

 Island, notably at Brooklyn, Greenpoint, Patchogue, Orient Point, 

 Shelter Island and Southhold. There is also a nearly extinct 

 infestation at Garrison. The season of 1921 was marked by the 

 finding of the gipsy moth in the southwest town of Vermont, which 

 means that through natural spread, the insect has virtually reached 

 the New York State line, and the same is almost true for the north- 

 west corner of Massachusetts. There has also been a marked exten- 

 sion in the southwestern portion of Massachusetts, the insect now 

 occurring in small numbers in the towns of Becket, Otis and 

 Sandisfield, all within about 15 miles of the New York State line. 

 There was in 1920 and also during the past season an effort on the 

 part of interested states, namely New Jersey and New York, and 

 the Federal Government to exterminate the above-mentioned iso- 

 lated infestations. Extremely gratifying progress has been made. 

 This is particularly evident in New Jersey where the larger and 

 denser infestation permitted a most striking contrast between the 

 three million egg masses found in the infested area in 1920 as com- 

 pared with less than one hundred disclosed by scouting at the end 

 of the past season. It is possible to prevent the dissemination of 

 this insect. The repressive and quarantine work of the Federal 

 Government in cooperation with the interested states has accom- 

 plished much in slowing up or checking what would otherwise have 

 been an extremely rapid spread. 



The snow white linden moth, Ennomos subsignarius 

 Hubn., was sufficiently abundant in portions of Otsego county in 

 1919 to defoliate large areas of woodland. The numerous moths 

 appearing in Albany the latter part of July probably originated 



