Life Hisforij Notes of Cranhernj Lake Ilomopierd 101 



although the latter if under equal pressure might have added 

 advantage of killing the insects and preventing a return of pests 

 by development of new generations from chance individuals sur- 

 viving the spray. 



In extensive forest areas or in large parks where direct applica- 

 tions are impracticable or impossible it may be advisable to cut 

 the badly infested trees and burn the infested branches and twigs 

 to prevent them from serving as centers for the multiplication 

 of the insect and their distribution to healthy trees. This has the 

 further advantage of directing the natural enemies which on the 

 whole are the main factor in preventing wholesale damage by the 

 pest to those trees that are less infested and thereby reducing the 

 numbers of the pest. Care in freeing nursery stock by spraying 

 or fumigating before planting should serve to prevent some of the 

 damage in newly planted forest areas. 



Natural enemies that have been noted are chrysopas, syrphids 

 and mites; and these play an important role in reducing the num- 

 bers of the pest. 



THREESPOTTED PSYLLIA 



Psyllia trimaculata Crawford 



Psyllia astigmata Crawford 



This species (Fig. 43) is a very conspicuous feature of the 

 locality, both nymphs and adults appearing in such numbers and 

 distributions as to attract attention. 



The nymphs were first noted as abundant on the Fire cherry 

 (Primus pennsrjJvanica) where the white cottony or woolly masses 

 covering the bodies of the insect and occurring on the under 

 surface of the leaves formed a very conspicuous object. (See 

 Fig. 44.) 



Nymphs observed July 3 were in final instar and adults were 

 observed emerging July 7. All adults noted July 7 and 8 w^ere 

 males, and agreed closely with descriptions and figures of 

 astigyyiata Crawford, for which no larval history has been recorded. 

 The woolly nymphs bear close resemblance to P. foccosa Patch 

 described from alder, but adult characters appear to be sufficient 

 to separate the tw^o species. While a very few scattered nymphs 

 have been well restricted to the fire cherry so this may be counted 

 the preferred if not the only host plant. Early nymphs have not 

 been observed but undoubtedly occur and develop during June, 

 probably hatching from eggs which have wintered in buds or bark. 



Nymphs of the last instar are light green, the wing pads whitish, 

 broadly ovate, the head short, wider than long, as wide as pro- 

 thorax. Antennae with terminal segment and apex of preceding 

 segments, 5-6-7, black, 3-4 tinged at tip, 1-2 pale. Ocelli 

 close to eye, dark ; eyes blackish ; pronotum short, beak light yel- 

 lowish, dark at tip ; wing pads of meso- and meta-thorax expanded, 

 wider than abdomen ; abdomen as wide as long and sub-truncate 



