364 JOURNAL OF ECONOMIC ENTOMOLOGY . [Vol. 6 



in the cell. The time spent as pupa varies from three to sixteen days, 

 the average being ten, and in the case of the specimens observed, 

 the adult always emerged at night. 



Mating, as a rule, takes place within the 36 hours following emer- 

 gence and during the next 36 or 48 hours eggs are deposited for the 

 next generation. The number of eggs deposited by one female varies 

 from 160 to 700 with an average in the several cases observed of 450. 

 These, as a general thing, are laid in two clusters, both during 

 the same night, while a few scattering groups of four or five may be 

 deposited the following night. The adults die in from four to eight 

 days; the eggs hatch in from two to four days; the young larvse 

 begin their work of destruction and the life cycle is complete. 



As determined in the insectary and checked by observations in 

 the field, the life cycle was found to cover a period of 30 days when 

 the mean temperature is 78°F. The time spent in the various stages 

 of development is as follows: egg, three days; larval stage, 14 days; 

 pupal stage, ten days, together with the three days necessary for 

 mating and oviposition; total, 30 days. The figures given are the 

 averages secured from the rearing of large numbers of individuals. 

 Naturally there was a great variation, some specimens requiring 40 days 

 while others completed the life cycle in 21. During the five months 

 from May to September inclusive, there were five generations in the 

 field, thus showing a field average of 30 days. 



Observations made in the field during October and November 

 showed 90 per cent of the eggs deposited during this time to be non- 

 fertile. Larvae collected in September and placed in breeding cages 

 for further study were all destroyed by natural enemies, which by 

 this time had become so numerous in the field that practically all 

 specimens were parasitized. These two facts render inconclusive 

 the evidence as to future generations, although occasional larvse 

 were found during these autumn months. 



Natural Enemies.^ — Before the first generation of worms entered 

 the soil in May for pupation, Tachinid flies and other parasites and 

 predaceous enemies put in their appearance. While located at a 

 temporary field laboratory at Irvington during August, 30 natural 

 enemies were found preying on Laphygma. Of these, 21 were 

 predaceous enemies and nine were parasitic. Of the predaceous 

 enemies eleven were Coleoptera, four were Hemiptera and six Hymen- 

 optera. The two most effective of the beetles were {Tetiacha Carolina) 

 a tiger beetle and (Calosoma calidum), one of the ground beetles. The 

 two most common of the true bugs which were preying upon the 

 species belonged to the family Reduviidae and have not as yet been 

 determined. The solitary wasps were very effective in their work, 



