Apanteles solitarius (Ratz.) was introduced into New England 
against the satin moth in 1927 and soon became established 
throughout the infested area. Parasitization as high as 67 per- 
cent has been recorded. The winter is spent either as a first-instar 
larva in a satin moth larva or as a prepupal larva in a satin moth 
cocoon. Thus, two separate broods of adults arise from the over- 
wintering generation, each of which produces a second genera- 
tion during the summer (577). 
Phanomeris phyllotomae Mues. was imported into New Eng- 
land and New York in the early thirties against the birch leaf- 
mining sawfly. It became established but its effectiveness in 
control has not been determined. There is one generation a year 
(204). 
Orgilus obscurator (Nees) was imported by the United States 
and Canada in the thirties against the European pine shoot moth 
and is now widely distributed in most shoot moth infested areas. 
Percentage parasitization is quite variable but often high in the 
United States, ranging from very low to as high as 50 percent. 
Significant levels of parasitization have also been recorded in 
parts of Canada. Winter is spent as a first instar larva within the 
hibernating host larva and there is one generation per year. 
FAMILY ICHNEUMONIDAE 
ICHNEUMONS 
There are approximately 2500 described species of ichneumons 
in the United States and Canada, and probably at least 5,000 
undescribed ones (716). The family has been divided into 14 sub- 
families and 53 tribes and subtribes (550). All members of the 
family are parasites of the larvae and pupae of holometabilous 
insects, or of spiders, spider egg sacs, or pseudoscorpions. The 
majority of insect hosts belong to the order Lepidoptera, but 
many species of Hymenoptera, especially the sawflies, and several 
species of Coleoptera are also attacked. 
Ichneumon adults vary greatly in size, form, and coloration. 
They resemble slender stinging wasps, but differ in having the 
antennae longer and with more segments, in having the tro- 
chanter two-segmented, in having the female ovipositor perma- 
nently extruded, and in lacking a costal cell in the front wing. 
They also resemble adult braconids but differ in having two 
recurrent veins in the front wing instead of just one. 
Forest and shade tree insects are parasitized by a great many 
species of ichneumons, far too many to mention here (550). The 
majority are native to this continent and attack native hosts. In 
addition to these, a number of species have been introduced from 
abroad against several important introduced hosts (205). 
Aptesis basizonia (Grav.), a European parasite of sawfly co- 
coons, was introduced originally into Canada against the Euro- 
pean spruce sawfly during the thirties, and several colonies were 
made available for liberation in the United States as well as 
Canada against both the European spruce sawfly and the Euro- 
pean pine sawfly. It became established on the European pine 
470 
