41 



breeding- cages. I have also seen Gnathocerns cornuiiis, another 

 eaill pest, attack and devour the flour-moth larvse in mills in 

 California. 



Parasitic Ijiscds.— The larva of the flour moth is attacked by- 

 several species of very small hymenopterous parasites. They are deli- 

 cate wasp-like creatures, which take advantage of the full-grown 

 larva of the flour moth during its migratory period just prior to 

 its pupation. While the delicate larva is thus exposed the winged 

 parasite lays her eggs, usually upon its body. In one instance at 

 least, that of Bracon hebetor Say*, the parent insect paralyzes the 

 larva, reducing it to a helpless conditioa before the eggs are de- 

 posited. 



The first trae parasite of the flour- moth observed, Bracon bre- 

 vicornis Wesm., was discovered by Mr. Sidney T. Klein in 

 August, 1887, in a London waiehcuse. He describes the attack 

 as follows: "I held an inspection in August, and brought away 

 several of the full fed larvae for examination, as I noted some 

 irregular markings which had not been noticed before. These 

 larv?e seemed to pupate quite regularly, and I did not suspect the 

 state of the case until 1 went down again at the beginning of 

 September. No sooner had I entered the warehouse than I 

 noticed a most extraordinary change in the appearance of the 

 large piles of flour. On closer examination I found this appear- 

 ance was caused by enormous numbers of a small black fly * * *; 

 and, upon examining several of the larva), the majority of which 

 had markings on their backs, the startling fact was established 

 that nature had come to the rescue and provided a remedy her- 

 self. It is very rarely that such a striking example of nature's 

 wonderful ounterbalancing powers is discovered." 



Mr. Wm. H. Ashmead, of Washington, D. C, who is our best 

 authority oa this group, informs me that Bracon brevicornis is 

 not found in North America so far as he knows. 



Specimens of Chremylus ruhiginosus were bred from EphesUa. 

 kuehniella and sent to Mr. J. B. Bridgman, of Norwich, England, 

 who records the fact in a communication to the editors of "Insect 

 Life" (Vol. IL, p. 260). In a letter from Mr. Ashmead, dated 

 September 21, 1895, he says: "I know this species only by Euro- 

 pean specimens. It is not yet recorded from North America." 



The present economic relationship of Bracon hebetor Say 

 to the flour moth was discovered by me September 2. 1895. 

 The insect was first described by Thomas Say in February, 1835,t and 

 is therefore an old-time species. Mr. Ashmead, who kindly de- 

 termined it for me, says: "I have seen specimens from California, 

 Indiana, Ohio, Illinois, District of Columbia, Virginia, New York, 

 Massachusetts, and other New England States, it is therefore a 

 widely distributed species. It comes very close to my Bracon 

 gelechice, reared by yourself from Canarsia hammondi, in color and 

 general facies, but differs in sculpture and antennal characters." 



* Belongs to Mr. Ashmead's new subgenue Habrobracon. 

 BcBt. Jour. Nat. Hist., Vol. 1, 1835, p. 252. 



