502 Journal of AgrictUtural Research voi. v, no. h 



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 ovipositions 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 the 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- 



