234 INSECTS INJURIOUS TO FOREST AND SHADE TREES. 
18. THE FIR HARLEQUIN CATERPILLAR. 
This caterpillar, more commonly found on the fir, is described on p. 239. 
19. Eacles imperialis Hiibner. 
This caterpillar is reported by Mr. Hulst to feed on the spruce. (Bul- 
letin Brooklyn Ent. Soe., ii, 77.) 
20. 'THE SPRUCE SAW-FLY. 
Lophyrus abietis Harris? 
Order HYMENOPTERA; family TENTHREDINID&. 
Occurring infrequently and not gregariously in Maine late in August on the spruce, 
a false-caterpillar; the body long, broader than the head; pale pea-green, the color 
of the leaves. Head smooth, concolorous with the body, with a dark patch extending 
upward behind each eye. Body with a dorsal dark green stripe, bordered on each 
side with whitish glaucous green. Along the body a lateral conspicuous broad white 
stripe, the stripe much scalloped below. Body beneath and proplegs uniformly green. 
Thoracic legs pale honey yellow, except at base. Length 17™™, 
No black spots on the body; though Harris says the larva of Lophyrus abietis is like 
that of Abbot’s white pine saw-fly. (See p. 197.) 
21. 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 following 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 antennz 
are short, 5-jointed and slender ; 
there are three straight veinlets 
, arising from the main subcostal 
~ vein and directed outwards, and 
there are no honey tubes ; other- 
wise these insects closely resem- 
Fic. 90.—The spruce louse.—From Packard. ble the Ap hides. A species 
closely related to the European Adelges (Chermes) coccineus of Ratz. 
burg, and the A. strobilobius of Kaltenbach, which have similar habits, 
we have found in abundance on the spruce in Maine, where it pro- 
duces 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 en- 
larged, 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 Hlinois, p. 156. 
