504 Phylum Arthropoda 



thick dough. Keep adding sugar and kneading until the dough becomes 

 "dry" and will not take up more sugar. Either a drop of honey solution 

 or a pellet of candy half the size of a pea is enough per tin. This is 

 placed on a i-inch square of heavy waxed paper, together with a separate 

 drop of clear water. The waxed paper food retainer is allowed to rest on 

 the surface of the soil. 



The propagation container is then ready to receive the female para- 

 site, which must be inserted quickly and covered with the lid. For each 

 female parasite, one container should be prepared as described, and then 

 set aside for 24 hours, after which it should be emptied and the parasite 

 transferred to a freshly prepared tin, with fresh host larvae that have 

 not been used previously, and with food. The tins may be kept at room 

 temperature, but if large numbers of parasites are to be reared, a con- 

 stant temperature of about 70 F. is best. 



The host larvae that have been so exposed to the parasite should be 

 examined both dorsally and ventrally for the parasite egg. Tiphiid eggs 

 are small, usually creamy white in color, and may easily be overlooked if 

 the examination is not thorough. 



Larvae bearing parasite eggs are then ready for transfer to the cross 

 section rearing trays. These trays, made of heavy galvanized iron, pro- 

 vide a single compartment for each grub as a further precaution against 

 injury and cannibalism. Trays may be made to contain any desired 

 number of compartments, but a convenient size for mass rearing is 18 

 inches by 18 inches by 2% inches. The edges should be rolled or folded 

 for strength and to prevent cutting of the hands, and the corners folded 

 and riveted. The inside of the tray is divided into 196 compartments 

 each 1 inch square by 2 inches deep. The cross partitions forming these 

 compartments are % -inch wooden strips cut so as to fit together like 

 the sections in an egg crate and are best made by machine. (If only a 

 few parasites are to be reared, the host larvae may be kept individually 

 in tin salve boxes filled with soil and the cross section trays will not be 

 necessary.) 



One host grub bearing the parasite egg is then placed in each com- 

 partment and fine, moist soil is sifted into the compartments and pressed 

 lightly into place. Just before the cross sections are completely filled, 5 

 or 6 grains of wheat or rye are placed in each compartment and then 

 covered with soil. The sprouting grain in the compartments furnishes 

 food for the host until it finally succumbs to the parasite. (If tins are 

 used, they too should be provided with grain.) The trays should be 

 moistened slightly at this time and then stacked and allowed to remain 

 undisturbed for about 1 month, at the end of which time cocoons should 

 be formed. For species inhabiting temperate regions, the optimum 

 temperature for development to the cocoon stage is about 70 F. 



