16 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



In Europe piceae occurs on many species of fir. It hibernates 

 on the bark as the stem mother larva which is elongate, black, 

 with a double, elongate brush of wax along the medio-dorsum and 

 a fringe of the same substance around the base. With the in- 

 auguration of spring it begins to grow and molt, the waxy down 

 likewise growing more profuse. By April it reaches maturity 

 and deposits about 140 light reddish brown eggs which hatch 

 during May into either summer stem mother (aestivalis) or winter 

 stem mother (hiemalis) larvae which settle on the old bark, the lat- 

 ter not completing growth until next spring, thus completing the 

 monoeceus, monomorphic annual fir cycle. The former reach 

 maturity between May and July, depending on the weather, and 

 lay a small number of eggs, all of which hatch into winter stem 

 mother larvae. Part of the summer larvae develop into nymphs 

 which are only covered by powder. These change into winged 

 migrants, all of which fly about May or June and settle on young 

 and old needles of Picea excelsa. The 7-12 eggs which these lay 

 there hatch into the sexed forms. In but four instances were these 

 eggs observed to have hatched and partly developed. But aside 

 from the hiemalis larva, which fully agrees with Borner's descrip- 

 tion of it, we know nothing of its other forms in this country. 



Economically Chermes piceae is regarded by some observers in 

 Europe to have been the cause of the serious injury and death 

 of many fir trees in a number of places. But those observations 

 were made prior to its differentiation from Chermes nusslini, 

 which is known to infest fir trees simultaneously with the othi-i . 

 and, the writer is inclined to agree with Niisslin that, of the two 

 species, the one sapping the vitality of the young growth is prob- 

 ably the more seriously injurious, the two together probably being 

 quite competent to kill good sized fir trees. Hence, if nusslini 

 is also found on the trees in New Hampshire reported dying, 

 these two species of Chermes may account for the deaths. Other- 

 wise, some other cause will probably be found primarily responsible. 

 But the heaviness of the infestation on the pieces of bark examined 

 would indicate that the species merits watching and further careful 

 study. It goes without saying that it likewise merits study from 

 the biological view point. 



