42 



I bred another specimen, a male, from the same lot oE flour- 

 moth larvse, which, although certainly different from typical males- 

 of Bracon hehefor, is probably only a small variety of this species. 

 Mr. Ashmead characterizes it as follows: "It differs markedly in 

 several particulars — number of joints in antennae, its more elon- 

 gated shape, much smaller size, and in color; but until the oppo- 

 site sex is bred, it would be better to consider it only as a vari- 

 ety of hehetor." This little braconid has been bred from the In- 

 dian ^meal moth, Plodia inierpiinctella, in Massachusetts. I hav& 

 reason to believe that we may expect some good results from it 

 in this country. Out of several hundred flour-moth larvas sent 

 me by the California miller, only one moth emerged, all the oth- 

 ers having been destroyed by the little parasites, of which I re- 

 moved twenty- seven specimens from my breeding cage. It is 

 surprising how easily these little creatures can be colonized. It 

 is only necessary to collect a quantity of the webbed flour con- 

 taining the flour-moth larvae and place it in a breeding- cage, into- 

 which the parasites are afterward introduced. Here they multiply 

 rapidly, and can be liberated at will in the worst-infested parts 

 of the mill. I have suggested this expedient to the president of 

 the milling firm from whom I received the larvse. 



I will now give, somewhat in detail, notes of my own observa-" 

 tions on Bracon hehetor. When I discovered this little parasite^ 

 I noticed that several of the flour-moth larvse were lying in the 

 bottom of the cage in a helpless condition, although presenting 

 the fresh and plump appearance characteristic of living larvae. 

 Upon examination I found that they were not dead, but in a state 

 of lethargy. Two larvae in this condition were removed from the 

 cage and placed in a glass tube, where they remained perfectly 

 motionless, but still gave on the fifth day evident signs of life by a 

 slight movement of the thoracic segments when touched with a 

 needle point. This movement was not noticeable on the sixth 

 day, and the larvae were dried up and shriveled two days later. 

 It is quite probable that this paralysis is caused by the adult 

 parasite, but in what way has not yet been worked out 

 satisfactorily. I have now several experiments in progress to- 

 determine . this point if possible. I have observed the same 

 paralytic state in larvae of Canarsia hammondi, and in nearly 

 every case have found the eggs of Bracon gelechio} either 

 on the body of the larvae or on the silk or web imme- 

 diately over them. In this latter case it is very important 

 that the larvae should not move after the eggs of the par- 

 asite have b^en deposited, as the little grubs hatching from them 

 are legless, and could not crawl far in search of food. I am of 

 the opinion that B. hehetor deposits its eggs in much the same 

 way. I have not seen the eggs of this species, but have found 

 grubs just hatched attached to the external surface of the flour- 

 moth larvae. In one instance, September 18, 1895, I removed a 

 larva from a cage with five grubs, just emerged, feeding upon it, 

 two of which were removed and placed in alcohol, and the others 

 were left for development. The following morning, at 8 o'clock,. 



