Pyralidae 351 



otherwise would cut their way through the caps and escape. These 

 aerating caps may be used repeatedly. 



Special care must be taken to prevent the food from becoming in- 

 fected with wild or stray larvae. The comb, when it is received from 

 the apiarist, is sterilized by placing in an oven at 6o° to 70 C. and 

 leaving for about 2 hours. The sterilizing process is primarily to kill any 

 wild larvae which might be present; otherwise, sterilizing would not be 

 necessary since fungus and other disturbing organisms do not attack 

 dry bee comb. After sterilization the combs are packed into metal cans 

 with close-fitting metal covers. The ordinary pretzel or lard can is very 

 satisfactory and easily handled. For the current supply of the comb 

 a smaller can is preferable. It may be refilled as needed from the 

 supply in the large can. The large storage cans should be kept, in a 

 separate room or at least some distance away from the culture bottles 

 containing the larvae and the moths. This is necessary since the young 

 larvae, if they escape from the culture bottles, may go a considerable 

 distance and may chance to get into the stored supply. If several stray 

 larvae get into the stored supply and are not apprehended, the next 

 generation will likely be sufficient to destroy the whole lot of combs. 



The larvae flourish in a temperature around 30 to 35 C. The regular 

 Drosophila incubator, or any other incubator which has a temperature- 

 regulating device, is satisfactory for incubating purposes. If an in- 

 cubator is not available a very serviceable one may be made of ordinary 

 fibrous building board. A convenient size is 4 feet wide, 3% feet high, 

 and 14 inches deep. Material 2x2 inches is adequate for the frame- 

 work and, if it is lined both inside and outside, leaves a 2-inch dead air 

 space in the wall. The shelves should be about 2 inches narrower than 

 the space inside and perhaps 2 inches shorter, permitting a free circula- 

 tion of air all through the incubator. It is helpful so to arrange the 

 shelves that the free space on one shelf is on the opposite side of the 

 incubator from the free space on the next shelf above. Also, if a small 

 fan is placed in the incubator it keeps the air disturbed and aids in the 

 aeration of the cultures. The DeKhotinsky thermo-regulator has proved 

 a very efficient and dependable mechanism for regulating the tempera- 

 ture. This regulator, attached to a 40-watt electric light bulb for each 

 shelf in the incubator, is a very adequate heating device and is easily 

 installed. 



The handling and inspecting of Galleria is comparatively simple and 

 easy, but different from that of Drosophila. Galleria may not be shaken 

 from the culture bottles into an etherizing chamber as in the case of 

 Drosophila. The food in the culture bottles is loose and dry, and also 

 the moths adhere firmly to the walls or to pieces of the comb. Further- 

 more, it is not necessary to anesthetize them in handling and examining 



