754 



Journal of Agricultural Research 



Vol. XX, No. 10 



during the incubation period was 74.30 per cent, eggs hatched in 21 days; 

 in mid-August, when the average humidity during incubation was 67.80 

 per cent, eggs hatched in 18 days; and in late July and early August, 

 1 91 7, when the average humidity of the incubation period was 65.57 P er 

 cent, eggs hatched in 1 3 days. 



Table I. — Record of temperature and humidity during incubation period of Neodiprion 



lecontei 



It is highly probable that normal development or acceleration is due 

 to the favorable combination or balance of both temperature and 

 humidity and that there are definite limits beyond which heat or moisture 

 would be either insufficient or excessive and result in retardation or 

 death. 



Notes on the response of larvae of this species to meteorological influ- 

 ences are few and somewhat contradictory. The author has observed 

 a decided retardation of activity, feeding, and development, when damp, 

 cold, and cloudy weather occurs in the warm season, and a corresponding 

 acceleration on sunny days. Colonies were found feeding near Falls 

 Church, Va., on November 5, the day being bright but after a heavy 

 frost, while S. A. Rohwer records "nearly full-grown larvae feeding on the 

 sheltered side of a tree even though it was below freezing and snowing 

 hard," near Trout Lake, Boulder Junction, Wis., on September 21, 1913. 



MATING AND COPULATION STUDIES 



The females occasionally are, or seem to be, active in finding a mate, 

 but more frequently they appear to resist the attempts to mate offered 

 by the male, sometimes cutting off portions of his antennas and legs with 

 their mandibles. In those instances where copulation was observed 

 there were no preliminary attentions or courtship. Intercourse takes 

 place with the pair in positions in which their abdomens are opposed. 

 It was observed once that the male arrived in position by crawling over 

 the female from head to posterior end. When his abdomen had reached 

 the end of the female's he swung his under hers. During copulation the 

 wings are held flat against the body; the legs are spread rather far apart, 

 the forelegs projecting anteriorly, the middle legs slightly anteriorly, and 

 the hind legs posteriorly; and the antennae are << S ually moved slowly, 

 up and down. 



