l'.ill] Hypera and Phytonomus in America 411 



damp and not too cold weather to develop and affects the 

 larvae in October and November and again in April and May. 



This fungus is known as Entomophthora sphaerosperma 

 Fres., and is a common disease upon many insects, the only 

 other representative of the Coleoptera reported as attacked is a 

 Lampyrid larva. The list of its hosts includes (Thaxter, 1888); 

 in the Lepidoptera, imago of Colias philodice and larvae of 

 Pieris; in Hymenoptera several Ichneumons, and a Halictus; 

 in Diptera, imago of the common house fly {Musca domestica) 

 and representatives of several families of small diptera; in 

 Coleoptera as noted above; Hemiptera, Apia's, Typhlocyba, 

 larvae, pupae, imagines; in Neuroptera; imago of Limnephilus( ?) ; 

 Thrips in various stages of a species on Solidago. This species 

 of fungus occurs in Europe as well as in America, here being 

 known from Maine to North Carolina and westward into the 

 Mississippi Valley. 



The fungus develops in the body of the host, as a network of 

 branching mycelia, some of the branches push through the 

 ventral wall and become attached as rhizoids to some surface; 

 over the body is formed a gray velvety coating of fine threads 

 which have penetrated the skin; on the tips of some of these 

 are formed conidia from these come temporary spores which 

 are shot away for some distance and may thus alight upon 

 another host and begin to grow. Resting spores develop 

 inside the host and probably may thus live over until the next 

 season. 



The sick larvae crawl up the plants during the night, ascend- 

 ing as high as possible, if on a slender stem or a grass blade they 

 coil themselves about it in a horizontal position. 



Arthur (1885) states that they die by noon, remaining in 

 this position and during the late afternoon have changed to a 

 velvety gray. By the next morning the larva is only a 

 blackened shriveled mass. 



This disease is so destructive to the larvae of Phytonomus 

 nigrirostris and Hypera punctata that there is rarely any cause 

 for worry on account of their injurious habits in the Eastern 

 States. When they appear in numbers any season they are 

 nearly all killed before reaching maturity. 



