186 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 7 



which has made it difficult to determine the exact number that occur 

 in a year. At most any time that an infested hive is examined all 

 stages of the bee-moth may be found. From this it was generally 

 assumed that the life history was short and that there were several 

 generations each year. 



In well-protected hives the development may continue throughout 

 the year without interruption. But usually the winter is passed with 

 about two thirds of the insects in the larval stage and the remainder in 

 the pupal stage. Warm spells during the winter may cause some of 

 the moths to emerge from their cocoons. In the laboratory many 

 moths emerged when the temperature was maintained at 60° F. Such 

 moths do not reproduce in localities where freezing temperatures are 

 at all frequent. Even the most vigorous moths, when exposed, cannot 

 withstand a freezing temperature for more than three days. Moths in 

 well-protected places cannot survive an outside temperature of 26° F. 

 longer than five days. The moths are never active during the day 

 when the temperature is below 50° F. \ 



For College Station, the following life history and duration of broods 

 has been carefully determined. 



The maximum number of moths which mature from the overwinter- 

 ing larvse and pupse appear about the first of April. These moths are 

 active for some time before any eggs are deposited and it is the middle 

 of April before the eggs are laid for the first brood of larvae. Usually 

 twelve days are required for the eggs of this brood to hatch, so by the 

 first of May most of the first brood of larvse are out. The larval 

 period of this brood is quite long, most of them feeding at least forty- 

 five days before completing their growth. A majority of the larvae 

 of this generation are ready to pupate by the middle of June, but there 

 is a considerable variation in the rate of growth, as some of the larvae 

 feed for six weeks longer before completing their growth. The pupa- 

 tion of the first brood occurs during the last two weeks in June and by 

 the first of July some of the moths of the second generation are to be 

 seen. 



The moths of this generation emerge at about the same time and 

 give the impression of constituting a very large brood. Most of the 

 eggs are laid very soon after the emergence of the moths and by the 

 middle of July all of the eggs for the second brood of larvae are deposited. 

 The higher temperature at this time of the year shortens the egg period, 

 only ten days being required for these eggs to hatch. There is a con- 

 siderable variation in the maturing of this brood of larvae. Normally 

 the larval period is shorter than for the first brood and by the first of 

 September many of the larvae are mature. Some of the larvae, however, 

 may continue to feed for as much as four weeks longer and then pupate. 



