SPRUCE PLANT LICE. 853 



37. The spruce bud-louse. 



Adelges abieticolens Thomas. 



Order Hemiptera ; family Aphid^. 



Deforming the terminal shoots of the spruce, producing large swellings, which 

 would be readily mistaken for the cones of the same tree. 



We take the followiug account and illustration from our Guide to 

 the Study of Insects: 



The genus Adelges was proposed by Vallot for certain broad, flattened plant- 

 lice which attack coniferous trees, often raising swellings on twigs like pine and 

 spruce cones. The antenuie are short, 5-joiuted and slender; there are three straight 

 veinlets arising from the main sub- 

 costal vein and directed outwards, 

 and there are no honey tubes; other- 

 wise these insects closely resemble 

 the Aphides. A species closely re- 

 lated to the European Adelges 

 (Chermes) coccineus of Ratzeburg, 

 and the^. stroMloMus of Kaltenhach, 

 which have similar habits, we have p^g 286.-The Spruce louse.-From Packard, 



found in abundance on the spruce in 



Maine, where it produces swellings at the ends of the twigs resembling in size and 

 form the cones of the same tree. We would add that each leaf-bud is enlarged, 

 having an Adelges under it. As those nearest the base mature first and leave their 

 domicile, the deformed leaf-bud stands out from the axis of the shoot, thus giving 

 the cone-like appearance to the end of the shoot. 



This has since been described by Prof. Cyrus Thomas in his Third 

 Report on the Injurious Insects of Illinois, p. 156. 



38. The European spruce bud-louse. 

 Adelges abietis Linn. 



We observed this species in considerable numbers on the Norway 

 spruces on the grounds of the Peabody Academy of Science at Salem, 

 in August, 1881. The deformation produced in the terminal buds and 

 twigs were like those figured in Ratzeburg's Die Waldverderbniss, Bd. 

 i, PI. 28, figs. 1, 2. 



39. Spruce-tree plant-louse. 



Lachnua abietis Fitch. 



Occurring on Abies nigra; the wingless females pubescent, broadly 

 oval, blackish, clouded with brown, with a faint ashy stripe on the 

 back; under side mealy, with a black spot near the tip; antennfe dull 

 white, with a black ring at the tip of each joint. Length to the tip of 

 the abdomen 0.15 inch. (Fitch.) 



It is probably this species which we have found in abundance on the 

 terminal branches of spruces at Brunswick, Me., in July and August. 



