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a week. I have found as high as 45 per host. (In some lly- 

 menoptera I have found several hundred per host. Once I 

 reared 338 from one larva of Megachile palmarum.) Pupation 

 takes place where the larvae have fed, and where they have 

 been numerous the pupae lie in a mass. The pupal stage is 

 about two weeks. 



Family Trichogrammidae. 



Pentarthion flavurn Perk. — This tiny egg-parasite I have 

 reared from eggs of Vanessa twmmieamea Esch., Deilephila li- 

 neata Fab., Nacoleia accepta (Butl.), Nacoleia blackbunu 

 (Butl.), Nacoleia m-eyrichi (Sw.), Archips postvittanus 

 (Walk.) and Amorbia emigratella^ Busck. From one to several 

 parasites develop in a single egg of the host, depending on the 

 size of the egg. From Nacoleia eggs I have had usually about 

 three per egg, while from the larger egg of Vanessa tammeamea, 

 24 emerged. This is a very beneficial parasite. It often de- 

 stroys a large proportion of the eggs of Nacoleia blackburni and 

 Archips postvittanus, and recently Amorbia emigratella — many 

 egg-masses of the latter being found entirely parasitized. It 

 has a very short life-cycle. I bred a generation in 10 days. 



The eggs of Bactra straminea are also parasitized, and Mr. 

 Fullaway has bred it from eggs of Heliothis obsoleta Fab. 



PentartJiron semifumatum Perk. — Reared from eggs of Her 

 se cingulata Fab. (Fullaway). I have reared it from the egg of 

 Deilephila lineata. One one occasion I reared 7 of this species 

 and 7 of P. flavum from one egg of the latter. 



Family Ichneumoxidae. 



Ichneumon Jcoebelei Sw. — This parasite was introduced 

 from America by Mr. Koebele about 15 years ago. It parasit- 

 izes Cirphis unipuncta (Haw.), the army- worm, Agrotis ypsi- 

 lon Rott., the black cutworm, and probably other related cater- 

 pillars, but does not accomplish much good, as it does not appear 

 to be very prolific. The parasite stings an egg into the cater- 

 pillar, where the egg hatches and the larva grows while the 

 caterpillar is obtaining its growth. The host is not killed till it 

 enters the ground to pupate. The parasite finally transforms 

 to the adult within the host pupa, without spinning a definite 

 cocoon — merely spinning a little silk on the inside of the empty 

 pupa case of the host. The adult finally emerges by breaking 

 an irregular hole at the anterior end of the pupa case. 



