' 





fler portion- of tin' m<l the di^nlved nitro;'. 



matl< >rbed into the plant. (' (r'nnl<irii ha- little bladd* 



entrap sm;ill aquatic ii rlially dl 



on in d, however, for they -ill ; hlorophyll. 



i.i cause epidemic di :nong in in tin- !la< : 



of the silkworm; and fin few group-; 



cially adapted to develop in the bodies of living 



Those who rear insects know how frequently 



rpillars and other larv;c are destroyed by fungi 

 that give the insects a powdered appearance. These 

 fungi, referred to the genus fsiiria, are in some cases 

 known lo be asexual stages of forms of Cordyceps, 

 which forms appear from th^ bodies of various larvae, 

 pupa- and imagines as long, conspicuous, fructifying 



ails i. Kij. 254). 



The chief fungous parasites of insects belong to 

 the lanje family Kntomophthoraceae, represented by 

 the common Empusa musca (Fig. 255) which affects 

 various flies. In autumn, especially in warm moist 

 weather, the common house fly may often be seen 

 in a dead or dying condition, sticking to a window- 

 pane', its abdomen distended and presenting alter- 

 nate black and white bands, while around the fly 

 at a little distance is a white powdery ring, or halo. 

 The white intersegmental bands are made by threads 

 of the fungus just named, and the white halo by 



ntless asexual spores known as conidia, which 

 have been forcibly discharged from the swollen 

 threads that bore them (Fig. 255) by pressure, result- 

 ing probably from the absorption of moisture. These 

 spores, ejected in all directions, may infect another 

 fly upon contact and produce a growth of fungus 

 threads, or hypha, in its body. The fungus may be propagated also 

 by means of resting spores, as found by Thaxter, our authority on the 

 fungi of insects. 



Knipi/sti <iplii<tis is very common on plant lice and is an important 



k upon their multiplication. Aphids killed by this fungus are 



toimd clinging to their food plant, with the body swollen and discolored. 



ns.i grylli attacks crickets, grasshoppers, caterpillars and other 



FIG. 254. Fruc- 

 tifying sprouts of 

 a fungus, Cordyceps 

 ravenelii, arising 

 from the body of a 

 white grub, Lachno- 

 sterna. Slightly 

 reduce d. A f t e r 

 RILEY. 



