LIBRARY

HEMIPTERA 326
These insects live on the twigs, needles, or in galls on coniferous trees. They
have complex life histories, consisting rarely of a single host, or alternate hosts,
comprising a primary host which is frequently spruce and an intermediate
host such as pine, larch, fir, hemlock, or Douglas fir. Galls are generally pro-
FIG. 111. Adelges tsugm Annand. Fundatrix. A, antenna; B, dorsal plate showing wax
pores; C, hind leg of 3rd instar nymph; D, hind leg of adult; E, post anal plate; F, knobbed
ventral seta. (After Annand, 1924.)
duced upon the primary host only. The forms involved in the polymorphic type
are summarized as follows:
1. Fundatrices - apterous, parthenogenetic females which hatch in summer
from the eggs laid by the sexual females on the primary host. They remain
immature throughout the following winter and in the spring lay
many eggs which give rise to the gallicolre.