16 



Fig. 12. Photograph taken at the base of an apple tree after some of the 

 covering leaves had been removed to show the adult apple flea-weevils 

 dead with the muscardine fungus. About 2/3 natural size. Small white 

 spots are dead beetles embedded in the fungus which killed them. Olney, 

 III., Oct. 18, 1915. 



Another controlling agency is a group of tiny hymenopterous par- 

 asites, of which several species have been bred. These busy little crea- 

 tures parasitize either the larva or the pupa in the mine, ultimately 

 causing the death of their host. We have never seen such wholesale 

 destruction as that due to the muscardine fungus, but these parasites are 

 undoubtedly an important factor in checking the activities of the insect. 

 For example, on June 12, 1919, material taken at Delaware, Ohio, was 

 found to be 23 per cent, parasitized, and on June 23, 1921. material taken 

 at Wooster, Ohio, was found to be 20 per cent, parasitized. The follow- 

 ing species have been reared: 



From mines of the apple flea-weevil in apple. Zatropis inccrtus 

 Ashm.*, Epiurus sp.f, Dcrostcrnns paUipcs Gahan* ; from those in choke 

 cherry, Pleurotropis sp.* ; from those in hawthorn, Sympiesis sp.*, and 

 Eulophid gen. and sp.* 



• Determined by A. H. Gahan, U. S. Bureau of Entomology. 

 t Determined by R. A. Cushman, V. S. National Museum. 



*> 



