CULTURE 



life cycle is completed in the shortest time at 

 33.5° C. and a relative humidity of 32-98 per 

 cent. The optimum temperature is, however, 

 29-30° C. with a relative humidity of 80 per 

 cent. The temperature optimum is considered to 

 be the temperature at which there is per cent\ 

 mortality and the smallest variation in the ef- 

 fect of various percentages of relative humid- 

 ity. The relative humidity optimum is found 

 on the humidity scale at the point where there 

 is the greatest range of temperature with the 

 same mortality. The duration of development is) 

 influenced especially by temperature and only 

 slightly by relative humidity. At the tempera- 

 ture optimum the mortality is not influenced by 

 slight deviations from optimum humidity, but at^ 

 non-optimal temperatures, either high or low, 

 there is an increase in mortality the farther 

 the temperature and humidity are removed from 

 the optimum. The mortality at non-optimal tem- 

 peratures is influenced considerably by humid- 

 ity; however, the duration of development of 

 the survivors is less affected. 



At optimum or near optimum conditions, the 

 deposited eggs hatch into larvae in two or 

 three days. The larvae feed on the juice of 

 the host caterpillar and grow to the size of 

 <two to five millimeters depending upon how much 

 'food is available. These maggot-like larvae 

 upon emergence cling to the integument of their 

 host. 



About three days after setting, or when lar- 

 vae are present on the caterpillars, the female 

 3hould be transferred to a new vial and given 

 fresh caterpillars. A small camel's hair brush 

 is useful in making such transfers, as the wasps> 



IS 



