204 
Journal of Agricultural Research 
Vol. XIV, No. 5 
later the last larval skin is pushed back upon this. The pupal period 
requires from 4 to 6 days, bringing the total time spent within the cocoon 
to from 7 to 9 days. The emergence of the adult is through an opening 
made by cutting off a circular lid at the lower end; thus the cocoon is 
left hanging in mid-air, even after the parasite has gone (PI. 21, G). 
Scheidter (5) in recording his observations on M. versicolor in Europe, 
states that the period from the issuance from the host to emergence from 
the cocoon is 13 to 14 days, while the pupal period alone is 9 days; but 
in no case that has come under the writer's observation has the period 
spent within the cocoon been as long as this. 
SUMMER HOSTS OF METEORUS VERSICOEOR 
The adults of the first generation emerge during the first two or three 
weeks of June. Mating takes place very soon after issuance, and the 
females begin ovipositing. Here, again, fertilization is not necessary for 
reproduction, but, as is true with A. lacteicolor , unfertilized females 
produce only males. 
In Europe Schmiedeknecht (6, p. 223) records M. versicolor from the 
following hosts: Laria v-nigrum Muller, Asteroscopus sphinx Hufnagel, 
Bombyx neustria Linnaeus, B . lanesiris Linnaeus, Triphaena pronuba 
Linnaeus, Geometra papilionaria Linnaeus, Eupithecia exiguata Hubner, 
and Argyresthia nitidella Fabricius. In New England the adult parasites 
of the first generation evidently prefer the last two stages of the brown- 
tail-moth caterpillars for oviposition. Only occasionally are gipsy-moth 
caterpillars attacked by this species; M. versicolor oviposits very eagerly 
in Hemerocampa leucostigma and Notolophus antiqua, however; Hyphantria 
cunea has also been recorded as a host (j, p. 289). This parasite has, 
besides, been observed frequently to insert its ovipositor into a larva 
in which dissection or rearing showed that no egg had been deposited. 
A number of specimens of Alsophila pometaria Harris were apparently 
oviposited in by M. versicolor, but no parasite was obtained on rearing, 
which was somewhat surprising, since the parasite has been recorded in 
Europe from Eupithecia exiguata, which also is one of the geometrid 
subfamily Hydriomeninae. Caterpillars of Phigalia titea Cramer (a 
geometrid), of Xylina antennata Walker (a noctuid), and of several species 
of Tortricidae, as well as larvae of a tenthredinid, were apparently ovi¬ 
posited in, but rearing and dissection showed that no eggs had been 
deposited. When even a membracid nymph was introduced into a vial 
containing a female of M. versicolor , the parasite advanced toward the 
hemipteron with ovipositor projecting forward between the front legs. 
Evidently M. versicolor often attacks from some motive other than that 
of oviposition. 
There is unquestionably at least a partial third generation on various 
native hosts, particularly upon the species of Hemerocampa, Notolophus, 
Hyphantria, and other closely allied forms, early stages of which are in 
