20 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.00. 



first, the ultimate stage feeding period varying from 2 to 3 days in 

 length and averaging 2.6 days for both males and females of both 

 the first and second generations; second, the ultimate stage between 

 feeding and spinning, a short time occasionally as long as a day; 

 third, the period spent between the spinning of the cocoon and the 

 appearance of the pupa, five and six days respectively in the two 

 opportunities in which the appearance of this stage was noted; and 

 fourth, the pupal period, 3 days in both instances noted. The total 

 length of the cocoon period, or the time spent between spinning and 

 adult emergence is shorter for the first generation, being 8-9 days in 

 length and the sex of the individual does not seem to be associated 

 with the variation in the length of the period, however, the second 

 generation ranges from 10-11 days which variation is associated with 

 the individual sex as follows: Ten days for the females and 11 days 

 for the males. 



BEHAVIOR. 



The adults of this sawfly are restless in nature but more so in 

 captivity, spending most of their time trying to escape. If jarred 

 or disturbed while on a leaf or twig, both sexes fall to the ground, 

 fold their legs, wings, and antennae, close their bodies and remain 

 motionless, a common habit among sawfiies. 



For this reason, observations on the habits and functions were 

 difficult to make, and at best somewhat superficial and wanting in 

 detail and exactness. The following notes on mating and oviposition, 

 however, were deemed worthy of publication. 



Mating. — A female from one isolation cage where she was reared 

 without access to a male and a male from another were placed in the 

 same vial — at first they paid no attention to each other, but later 

 the male became much agitated and when in close proximity to the 

 female exerted his genitalia and endeavored to grasp the female with 

 the harpes. In a few attempts he was unsuccessful, but after the first 

 few trials the female became more submissive and remained quiet, 

 not avoiding the male. A few seconds later a union was effected. It 

 was very short, and with the exception of motion of apical part of 

 abdomen the insects were motionless. On completion the female was 

 the first to show desire to break away, and pushed her ovipositor down 

 against the top of the abdomen of the male. When the male left 

 the female, he remained quiet for a few seconds and again resumed 

 his activity. No other attempt of mating was observed. The posi- 

 tion normal for Nematinae was the one assumed.* 



Oviposition. — The eggs of Gladius isomerus are laid in the midrib 

 of the leaf from the upperside and in the middle of the fluting. 

 Upon arriving at a favorably considered place for oviposition the 



•The Mating Habita of Some Sawflies, S. A. Rohwer, Proc. But. Soc. Wash., vol. 17. 

 1915. pp. 196-8. 



