XATUKAL ENEMIES. 41 



.- 

 headed grosbeak, Zamelodia melanocephala; rough-winged swallow, Stelgidopteryx 

 semripennis; sage thrasher, Oreoscoptesmontanus; Western robin, Planesticus migratorius 

 propinquus; Rocky Mountain toad, Bufo lentiginosus woodhousi; leopard frog, Rana 

 pipiens; salamander, Ambly stoma sp. 



Fungous Enemies. 



Whenever the larger species Hypera punctata (fig. 2) becomes 

 excessively abundant east of the Mississippi River, myriads of 

 these larvae may be observed coiled about 

 the uppermost tip of blades of grass or 

 similar vegetation, where they soon die and 

 become black. These are apparently de- 

 stroyed by a fungus, Empusa spliserosperma. 

 When investigations of the alfalfa weevil 

 were first undertaken there were great 

 numbers of these dead and dying larvae to 

 be found in Washington, D. C, in Potomac FlG . 27 .-cocoon TthT alfalfa weevil 

 Park. They were gathered up and sent showing cocoon of the parasite 



,, oij_ti /tj_ i i i • /i Canidiella cu rculionis within. Much 



out to bait Lake City and placed m the enlarged. (Original.) 

 hands of Mr. Ainslie with the hope of in- 

 troducing this fungus among the larvae of the alfalfa weevil. The 

 experiment appeared to have been a failure, and it was thought 

 that the climate of TJtah was too dry to enable this fungus to 

 exist there. Later this larger species was found in Utah, as has 

 already been stated, and during the spring of 1911 the fungus 

 was found in the vicinity of Salt Lake City. Apparently, how- 

 ever, the fungus does not affect the larvae to the same extent 

 that it does here in the East, except after these have reached 

 their full size and constructed their cocoons. Larvae of the alfalfa 

 weevil (fig. 5) and pupae (fig. 7) soon began to be observed in the 

 cocoon (fig. 6) dead and thoroughly permeated with this fungus. 

 No individuals in any case were found dead excepting within their 

 cocoons. On June 13 in the vicinity of Salt Lake City it was 

 estimated that one-fifth of the cocoons contained dead larvae or 

 pupae. In the Weber Valley, about Hoytsville, Utah, on the last 

 of August, it was found that of 580 cocoons examined 258, or 44.5 

 per cent, were dead, partly at least because of infestation by this 

 fungus. Examination at another point showed that 38 per cent had 

 apparently died from the same cause. To all appearances, then, this 

 was more effective in killing the alfalfa weevil than all other natural 

 enemies combined. 



