5°2 
Journal of Agricultural Research 
Vol.V, No. 12 
LENGTH OF LIFE CYCLE 
The total length of the life cycle, as obtained in the series of experiments 
carried from the last of September to the last of October, averaged 25 
days. A series of experiments conducted during the first two weeks of 
August to determine the time spent by the third instar and pupa in the 
cocoon varied from 5 to 7 days, as compared with 11 to 12 days during 
September and October. This great reduction in the time spent in 
these periods of development raises the question whether or not the time 
spent in the host would not be shortened under summer conditions. 
Unfortunately, this point could not be determined; but considering that 
the duration of the larval life of the army worm varies from 20 to 30 
days, according to Slingerland (8), it seems not unlikely that the length 
of the egg and internal larval stages would vary correspondingly with 
the life of the host. 
COPULATION 
The following observations were made on these insects confined in 
test tubes and lantern-globe cages. The male pursued the female, 
caressing her with his antennae, often mounting her posteriorly and, 
thrusting his abdomen forward, bringing the ventral surface in contact 
with that of the female. Once union had taken place the male folded 
his wings and drew his legs close to his body, holding on to the female 
solely by his genitalia. It was noticed that in the case of a number of 
males and females confined in test tubes for several days, copulation 
continued to take place day after day with unabated vigor. 
OVIPOSITION 
The parasite apparently recognizes the host on touching it with its 
antennae, and following such recognition the ovipositor is bent beneath 
the thorax, sometimes slowly but usually quickly, and is then rapidly 
thrust into the caterpillar. This being done, the parasite folds its wings 
and draws its legs up close to its body, holding on to the caterpillar 
solely -by its ovipositor, this no doubt being done to protect itself from 
the attacks of its host. During the process of oviposition the caterpillar 
may throw itself about violently, but rarely dislodges the parasite. 
Of the number of apparent oppositions in larvae of the third, fourth, 
and fifth stages, one-sixth of those which took place in the third, one-fifth 
of those in the fourth, and one-half of those in the fifth stage were unsuc¬ 
cessful. Usually the parasite larvae emerge after the caterpillar is full 
grown, as observed in the case of larvae collected in the field and those 
parasitized in the laboratory under artificial conditions, but in one 
instance where the parasite oviposited in a caterpillar of tide third stage 
the parasite larvae issued during the fifth stage. 
Parasites readily attempted to oviposit in caterpillars of the fifth and 
sixth stages, but were apparently unsuccessful, on account of the tough- 
