68 
Psyche 
[June-Sept. 
of approximately 11 months, in the egg stage in the buds of 
trees. The larvae are fully formed in the eggs within 20 days 
after deposition and they then remain in diapause for the 
remainder of the period. The duration of the first larval 
stage is variable, depending upon the length of time from 
hatching to entry of the planidium into the host nest, after 
which it must await pupation of the host individual before 
proceeding with its own development. The second and 
third larval stages and the pupal stage are passed very 
quickly and require 3, 4 and 6 days, respectively. 
The incomplete data presented by Parker (1937) on 
Stilbula cyniformis indicate that its cycle may be similar to 
that of S. tenuicornis. Adults are present only during 
August and the females oviposit in the seed receptacles of 
Picris. The egg masses are blown away with the seeds a 
short time later and they may not hatch until the following 
spring. 
Practically all the species found in distinctly temperate 
regions have only a single generation each year. Eucharis 
scutellaris of Chosen, which appears in the adult stage only 
during June, oviposits in flower buds, and the incubation 
period is only 15 days. In 1928 an examination of the colony 
site on June 4 revealed no adults, but these were present in 
numbers on June 7. A large quantity of Formica cocoons, 
comprising those of both the large females and the smaller 
workers, was collected on the latter date. In the large 
cocoons all parasites except two were in the pupal stage, 
and these two were prepupae. In the worker cocoons, how- 
ever, the hosts had not yet transformed to pupae and their 
parasites were consequently in the first larval stage. There 
being only one generation per year, it appears that the winter 
must have passed by all individuals in the first larval stage 
upon the ant larvae. 
A similar annual cycle is followed by Orasema coloraden- 
sis in Virginia. Oviposition occurs only during July, and 
the eggs hatch in less than 2 weeks. In the tropics the cycles 
of the species of the various genera observed are much 
shorter, probably not exceeding 1 month, and adults are 
present throughout the year if climatic conditions are favor- 
able. The incubation period of Schizaspidia convergens of 
