608 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
September, and the winter is spent as a first instar within the hiber- 
nating host larva. Development is completed in the spring, and the 
full-grown larva issues from its host to spin its cocoon. It usually 
crawls some little distance along a twig or branch and then, suspend- 
Ficurr 186.—Female of Meteorus 
versicolor and cocoon from 
which it emerged. 
ing itself by a strong thread, which it 
has made secure, forms an elongate- 
oval, golden-brown cocoon (fig. 186). 
Although this habit of spinning a co- 
coon in midair might be expected to 
afford some protection from hyper- 
parasites, actually the cocoons are 
heavily attacked by secondaries. 
The adult M/eteorus emerges in about 
9 days, and adults of the first genera- 
tion are present in the field about the 
middle of June. The later instars of 
the brown-tail moth and satin moth 
larvae, as well as some other hosts, are 
attacked. Adults of the second gen- 
eration, together with adults of a par- 
tial third generation, attack the hiber- 
nating larvae. 
Orgilus obscurator (Nees) is a par- 
asite of the European pine shoot 
moth (Rhyaciona buoliana). It be- 
came established in this country with 
its host, but did not become generally 
distributed until after liberations were 
made in the program of parasite intro- 
duction against this pest, begun in 
1931. In Europe it is an important 
parasite of the shoot moth in England, 
Holland, and Austria, but in Holland 
and Austria its efficiency is greatly re- 
duced by a secondary parasite, Peri- 
lampus tristis Mayr. The adult is 
black, about 14 inch long, with dusky 
wings and reddish legs. The female 
oviposits in small shoot moth larvae, 
and spends the winter as a first instar 
within the hibernating host larva. De- 
velopment is completed early in the 
summer, and the parasite emerges from 
the full-grown host larva or pupa to 
spin a thin, white cocoon inside the 
host’s burrow. Adults emerge from 
the middle of June until the middle of 
July. There is only one generation a year. 
Spathius canadensis Ashm. (fig. 187) 1s a parasite of a number of 
host species, and is commonly reared from the native elm bark beetle 
