116 SEVENTEENTH Report STATE ENtomoLocist oF MinNnEesota—1918 
This was repeated a second time and engorgement secured and eggs 
iaid when soil moisture was the only food obtainable. 
The periods of the life history are very irregular owing to the 
difficulty which some individuals meet in finding a sufficient food sup- 
ply. As soon as the female has become engorged with food she pre- 
pares for oviposition. The larger number oviposit between April 22 
and June 25. The mating process has not been observed except that in 
a breeding cage on one occasion in early April several pairs were 
engaged in what seemed a mild acrobatic contest. Altho the cage was 
watched closely no actual mating was seen. 
The eggs may be placed at the surface under leaves or other de- 
tritus, or beneath the surface at a depth of three-eighths to one-half 
inch. The eggs are cemented together rather firmly and the mass 
further bound together by a few silvery silken threads. Each mass 
may contain from two hundred to four hundred eggs, depending upon 
the extent to which the female has been able to secure food before 
oviposition. The incubation period of the eggs is from three to five 
weeks, depending upon the temperature. At about the middle of the 
period of incubation the outer shell of the egg splits open and the 
legs of the embryo covered with the inner membrane protrude in a 
conical fashion above the ruptured edges of the egg shell. At this time 
the mass of eggs assumes a paler color. Hatching of the larvae occurs 
from late May to mid July. 
Soon after hatching the six-legged larva crawls about upon the soil 
and up onto the vegetation, always going upward in search of some 
insect to which it may attach. Apparently plant lice are their favorite 
host. Several tried to engorge on adult Arphia pseudonietana and 
Chortophaga viridifasciata, but were unable to do so. They refused 
to feed on small beetle and ant larvae. The soft bodied aphid is more 
easily punctured by their small mandibles. They were reared on aphids 
from red clover, lettuce, box-elder, snowball and raspberry. As many 
as five or six may attach to one aphid, and in two to four days will 
swell to many times their original size. If disturbed or for any other 
reason dissatisfied they will detach themselves and roam about until 
they find another suitable aphid to which they will attach and feed. 
When, however, they are nearing engorgement removal from the host 
is difficult or impossible. 
When fully engorged the larva drops to the soil and burrows one- 
eighth of an inch to two inches below the surface, depending on the 
character of the soil, and there it goes into a resting condition. This 
securs usually during the month of June or early July. While in this 
