258 ENTOMOLOGY 
ent on insect-food, however, for they all possess chlorophyll. 
Bacteria cause epidemic diseases among insects, as in the 
flacherie of the silkworm; and fungi of a few groups are spe- 
cially adapted to develop in the bodies of living insects. 
Those who rear insects know how frequently caterpillars and 
other larvee are destroyed by fungi that give the insects 
a powdered appearance. These fungi, referred to the genus 
Tsaria, are in some cases known to be asexual stages of forms 
of Cordyceps, which forms appear from the bodies of various 
larvee, pupze and imagines as long, conspicuous, fructifying 
sprouts (Fig. 250). 
The chief fungus parasites of insects belong to the large 
family Entomophthoracez, represented by the common FLimpusa 
musce (Fig. 251) which affects various flies. In autumn, 
IGS 25. 
Empusa musce, the common fly-fungus. A, hone fly (Musca domestica), sur- 
rounded by fungus spores (conidia); B, group of conidiophores showing conidia in 
several stages of development; C, basidium (b) bearing conidium (c) before discharge. 
B and C after THAXTER. 
especially in warm moist weather, the common house fly may 
often be seen in a dead or dying condition, sticking to a win- 
dow-pane, its abdomen distended and presenting alternate black 
and white bands, while around the fly at a little distance is a 
