PARALYZED CATERPILLARS AND FULL GROWN MAGGOT 

 Caterpillars, after they have been stung by wasps, become torpid, but the heart continues to 

 beat even though they have lost ability to move. The dark line in the region near the middle 

 of the back in the caterpillars is the heart. It may be seen faintly in the photograph. Dark red 

 testes situated just back of the middle of the body distinguish the males, (about x5) (Fig. 14.) 



The caterpillars feed not only upon 

 various cereals, but are carnivorous as 

 well. On one occasion a number of 

 moths were killed and mounted for 

 reference. A few eggs which had been 

 extruded at death, adhered to the 

 bodies. Larvae hatched, devoured 

 their parents, spun webs and formed 

 pupae. 



WASPS AS MATERIAL FOR GENETIC 

 EXPERIMENTS 



The parasitic wasp, Hadrobracon 

 brevicornis (Wesmael), has proved to 

 be excellent material for genetic work, 

 and should be of value for other experi- 

 mental purposes as well. The insect 

 resembles Drosophila in size and in the 

 duration of its life. It may be conven- 

 iently reared in shell vials, 20 mm. x 70 

 mm. For continuous work a constant 

 supply of full grown Kphestia larvae is 

 necessary; but should the food supply 

 fail, the wasps may be set away in the 

 ice chest or even at freezing tempera- 

 tures and kept for months. Mass 



A PARALYZED CATERPILLAR AND WASP 

 EGGS 

 The illustration at the left is a mirror image 

 of the under side of a paralyzed caterpillar. 

 Eggs of the parasitic wasp Hadrobracon brevi- 

 cornis may be counted in normal position 

 between caterpillar and glass. In the picture 

 at the right, the caterpillar has been rolled over 

 and the wasp eggs photographed directly. (x4). 

 (Figs. 15 and 16.) 



