NATURAL ENEMIES. 41 
headed grosbeak, Zamelodia melanocephala; rough-winged swallow, Stelgidopteryx 
serripennis; sage thrasher, Oreoscoptesmontanus; Western robin, Planesticus migratorius 
propinquus; Rocky Mountain toad, Bufo lentiginosus ivoodhousi; leopard frog, Rana 
pipiens; salamander, Amhly stoma sp. 
FuxGOUs Enemies. 
Whenever the larger sjDecies Hypera punctata (fig. 2) becomes 
excessively abundant east of the i\Iississippi 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 b}" a fungus, Empusa spliserosperma. 
Wiien 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 fig. 27.-c~ocoon oTthl aifaifa weevil 
Park. They were gathered up and sent showing cocoon of the parasite 
, I r\ -K ,^ T ^ r^• , ^ ^ i • l^ CanidieUacurcuJionis vdthin. Much 
out to Salt Lake City and placed m the enlarged. (Ori?inai.) 
hands of 3Ir. Ainslie with the hope of in- 
troducmg this fungus among the larvse of the alfalfa weevil. The 
experiment appeared to have been a failure, and it was thought 
that the climate of Utah was too dr}^ to enable this fungus to 
exist there. Later this larger species was found in Utah, as has 
already been stated, and durmg the sprhig of 1911 the fungus 
was found in the vicinity of Salt Lake City. Apparenth', 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. Larvse of the alfalfa 
weevil (fig. 5) and pupse (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 vichiity 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 exammed 258, or 44.5 
per cent, were dead, partlj^ 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. 
