500 Phylum Arthropoda 



parasite which is living in the host aphid. A. inquisitor will not oviposit 

 until at least 2 days after the egg of Aphelinus jucundus has hatched. If 

 the temperature is lower than usual an even longer time must elapse. 

 The life cycle covers a period of about 3 weeks. 



Asaphes americana has proved to be both a secondary and a tertiary 

 parasite. It will not oviposit in parasite-free aphids, nor in parasitized 

 individuals until the latter are dead and have turned black. The life 

 cycle extends over a period of approximately 3 weeks. 



As far as could be observed Aphelinus jucundus reproduces only 

 parthenogenetically and all individuals are females. Aphidencyrtus 

 inquisitor and Asaphes americana reproduce both sexually and par- 

 thenogenetically; in the latter case all progeny are males. No more 

 than one parasite has been known to emerge from a single aphid al- 

 though in the breeding cages more than one egg might frequently be 

 found in one individual. 



Family trichogrammidae 



PRODUCTION OF TRICHOGRAMMA 



Stanley E. Flanders, University of California 



THE parasitic wasp Trie ho gramma minutum will develop from egg to 

 adult within the eggs of individuals of other species of insects 

 representing six different orders and many families and genera.* Hence 

 it is not surprising that it should develop in the eggs of Sitotroga, a form 

 that it probably never attacks under natural conditions. The first 

 attempt to use this insect as a host was made by the writer in 1926. 

 Because it proved adaptable, unlimited quantities of a suitable medium 

 for rearing Trichogramma became available. Sitotroga eggs may be 

 held in refrigeration for several weeks without becoming unsuitable. 

 [See P. 345.] 



The eggs are most easily handled and parasitized when fastened to 

 cardboards of convenient size. This is accomplished by pouring the 

 eggs on freshly shellacked cards and shaking off all of the eggs not ad- 

 hering. The shellac at the moment of applying the eggs should be just 

 sticky enough to hold them, but should not engulf them. The prepara- 

 tion of these egg cards is facilitated by giving the cards a primary 

 coating of shellac and allowing it to dry thoroughly. Owing to a soluble 

 coating on the surface of Sitotroga eggs, water may also be used in 

 fastening the eggs to almost any surface. 



♦Editor's Note: M. F. Bowen reports (Ann. Ent. Soc. Amer. 29:119, 1936) using 

 eggs of the, bagworm Thyridopteryx ephemeraeformis as host material for Trichogramma 

 and putting a fresh seedless raisin on a pin in the cork of each breeding container. The 

 raisin was moistened daily to help in maintaining a favorable relative humidity. M. E. D. 



