no SECOND REPORT OF THE STATE ENTOMOLOGIST. 



proposed exposing the infested material in close tanks to carbonic acid 

 or azotic gas.* 



Natural Enemies. 



Mr. F. M. Webster has bred from the larvse of this moth a hymen- 

 opterous parasite, which he has named and described as Pteromahis 

 'jekclticB {I'ilh Report Insects of Illinois, pp. 151-2). It occurred in 

 considerable numbers — often as many as eight or ten of its pupae being 

 associated with a single larva. It is probably the same parasite that Mr. 

 R. Owen had discovered in Indiana, in 1846, preying upon these larvae, 

 of which " some farmers had noticed large numbers among the tailings 

 of the winnowing machine." It was figured by Mr. Owen,f but not de- 

 scribed or named. From the figure, Dr. Harris recognized it as belong- 

 ing to the (JhalcididcB, and thought that it might be a species of 

 Fteromalus [Insects Injurious to Vegetation, p. 509), 



Mr. Webster also discovered a mite preying upon the larvae and de- 

 stroying numbers of them. It proved to be Heteropus ventricosns New- 

 port [Linn. Soc. Trans., 1850), repre- 

 sented in Fig. 21, after Walker from New- 

 port. The same species has been found 

 by M. J. Lichstentein of Montpelier» 

 France, infesting his breeding cages to 

 such an extent as to destroy nearly all the 

 Hymenoptera, Coleoptera and Lepidop- 

 ^^^ J tera that he attempted to rear. It was 



Fifi. 21.- Heteropus vENTEicosus, a mite described by him as Physogaster larva' 



pipviim'iipon the Ansoiimols moth : <i, a ma- 



tini' niillviUual; 6. female (listenilod with f'Wn . 



eggs— both enlarged; c, leg greatly enlargea. 



(After Newport.) For the interesting obscrvations of Mr. 



Webster upon the rapid and abnormal development of this mite, and 

 the vigorous attack made by it upon its prey, the reader is referred to 

 Prof. Forbes' iWi Report on the Insects of Illinois, as previously cited. 



DIPTEROUS INSECTS. 



Bibio albipennis Say. 



The White-unnged Bibio. 



(Ord. DiPTERA : Fam, Bibionid^.) 



S.\Y: in Journ. Acad. Nat. Sci. Phila,, iii, 1828, p. 7?; Complete WHting's, ii, 

 1859, p. 69. ^^ 



*Annales de V Agriculture Francaise for 1838. 

 t Cultivator, N. S. iii, November, 1846, p. 344. 



