28 PHYCOMYCETES 



Van Tieghem. Troisieme memoire sur les Mucorinees. Ann. 



Sc. Nat. VI. 4: 312-398. PI. 10-13. 1876. 



Some of the American species have been catalogued by 

 Pound. A Revision of the Mucoraceae with especial Reference 



to Species reported from North America. Minn. Bot. Studies, i : 



81-104. 1894. 



Order 3. ENTOMOPHTHORALES. 



The Entomophthorales are parasitic on flies, grasshoppers, the 

 larvae of beetles and other insects. They sometimes produce 

 destruction of insects in large numbers. The common Empusa 

 niuscae or fly fungus is one of the most familiar examples of this 

 order. It is a common thing in autumn to see flies with white 

 swollen bodies hanging dead on walls and windows with a white 

 radiant halo surrounding them. These are the victims of the fly 

 fungus. Within the body is the mycelium of the fungus pro- 

 ducing the death of the victim and developing simple conidia which 

 are thrown to some distance and form the halo. Sexual repro- 

 duction takes place by conjugation and in some species only 

 zygospores are produced. In late summer it is common to see 

 grasshoppers wearily crawl up the stems of mulleins or thistles, 

 turn black in the face and die, clinging with a death grip to the stem 

 on which they have climbed. These insects are full of the mycelium 

 of a mould which has been slowly sapping their vitality. After 

 their death, spores are formed which are more easily distributed 

 because of the last act of the insect seeking an elevated position. 



A third instance is seen in a parasite of the clover weevil. The 

 fungus affects the insect in the larval condition, in which state the 

 insect feeds on the roots of clover ; when a certain stage in the 

 growth of the fungus is reached, the larva becomes weary of life 

 and lazily crawls up a blade of grass, coils horizontally around the 

 tip (Pl.j.f. 7) and dies; from his elevated position spore dis- 

 semination is simple. Over fifty species are known belonging to 

 seven genera; four-fifths of the species belong to the genera Em- 

 pusa and Entomophthora. The American forms have been 

 carefully studied by Thaxter. 



LITERATURE. 



Schroeter. Loc. cit. 134-141. 

 Saccardo. Sylloge Fungorum, 7 : 280-286 ; 9 : 349-357. 



