THE SEMITROPICAL ARMY WORM. 63 



4 days, and in another case from July 18 to 22, or 4 days. In the 

 first instance the temperature averaged between 7G° and 80° F. and 

 in the second from 80° to 88° F. Evidently this is the maximum 

 period. 



As regards the duration of the entire life cycle, it was noticed that 

 eggs deposited Juh' ;> produced caterpillars on the 0th, or in (J days. 

 These penetrated the earth, being full-grown, on the 2Gth, making the 

 entire life period of the larva^ 17 days. They began to issue as moths 

 August 5. This gives a total period for the life cycle of 31 days for 

 extremely hot weather. Tn an ordinary outdoor summer tempera- 

 ture the period would be about 85 days, or 5 weeks. 



Our rearing records are not quite as accurate as could be desired, 

 owing to unfortunate conditions at the insectary and to three changes 

 in the office force during the time when the insect was under observa- 

 tion. There were, however, positively four generations here, and 

 about the same number was observed at Orlando. There is also 

 the possibility of an earlier fifth generation in nature. The exact 

 periods for the appearance of these should be recorded in the field. 



NATURAL ENEMIES. 



The unusual abundance of this species at Orlando, Fla., during the 

 season of 1907 afforded a most excellent opportunity for the study 

 of its insect natural enemies. These came under observation as earlj' 

 as May and were still abroad as late as August, appearing to increase 

 somewhat as the season advanced. 



PARASITES. 



The parasitic species observed Avere seven in number; the pre- 

 daceous enemies, six. 



Ophion tltyrl Pack. (?) — Issued July 17-August 1. 



Limnerium sp. — Issued May 25-30. 



Meteor us sp. — Issued July 11-August 2. 



Chelonus sp. — Issued July C, 1908. 



Spilochalcis spp. — The Meteorus was attacked by two species of 

 secondar}' parasites of the family Chalcidida\ These issued August 

 2 from the peculiar brown cocoons of the Meteorus. 



Winthemia qiiadripustitlata Fab., a moderate-sized taohina fly. is 

 also a parasite on the larva of this species. Adults issued August 8 

 but did not appear abundant. Of a lot of larva* taken at random 

 from different portions of a fiekl, upward of 50 per cent bore tachiua- 

 fly eggs. Evidently a large percentage fail to hatch." 



"A small fly was also observed feeding ou the pupae. It is Aiiliiaclnrtii nitjri- 

 ceps Loew, one of the Phoridre, which comprises species of scavenging habits 

 and not parasitic. 



