58 



Having- had some previous experience with an insect-destroying 

 fungus of a similar appearance in the destruction of (juite a different 

 insect in the United States, a preliminary examination of these fungous- 

 covered locusts at once suggested a Sporotrichum. But in order to 

 obtain a verification of this surmise, or to learn definitely the nature 

 of the find, specimens of the dead fungus-co\ered insects were sub- 

 mitted to Prof. C. E. Bessey, of the University of Nebraska, who 

 reported that the identification was correct. Although the genus to 

 which this South American locust-kiUing fungus belongs has been 

 definitely settled, various unavoida])le circumstances have thus far 

 prevented its specific identification. 



Locusts that have been attacked by this South American fungus, 

 instead of climbing to the top of various plants so as to get as much 

 air and light as possible, creep awa}^ from the light and seek dark, 

 moist places in which to die. Consequentl}' the}' are most often found 

 hidden away near the roots of bunch grasses, in the midst of dense, 

 juicy foliage. Here, after death, their bodies become entirel}^ filled 

 with mycelial threads and spores of the fungus. In many cases, 

 under certain conditions, the fungus growth also appears upon the 

 outside and almost completely covers the dead body of the insect. 



Some breeding-cage experiments attempted later in the year indi- 

 cated that the fungus could be quite readily transmitted from these 

 dead fungus-covered saltonas to live, healthy locusts of the same 

 species. While out in the open "camp," the invading swarms soon 

 began djdng in rather large numl)ers in the vicinit}^ where the fungus 

 had first ])een discovered. On gathering the dead bodies of these latter 

 and pulverizing them, and afterwards strewing this powder upon others 

 along with their food, the result was that the}^ too were found to sicken 

 and die. 



The action of this fungus upon the host is similar to that of Sporo- 

 trichum, glohuliferum on the chinch bug. At first the victim becomes 

 restless, ceases feeding, and begins to wander aimlessly about, and, 

 shortly before death, it seeks a secluded spot in some dark nook upon 

 or near the ground. Quite frequently, after a passing flight of an 

 infected swarm, the ground was found to be strewn with the dead 

 bodies of such insects as had succumbed to the disease. These soon 

 turned bright pink in color, and where they failed to reach a suffi- 

 ciently moist and shady place shortl}^ became ({uite hard and leathery 

 in texture instead of rotting and breaking into fragments, as is custom- 

 ary with dead insects of this class. Also at the "roosting places" of 

 such swarms many of these pinkish-colored locusts were found upon 

 the ground, having succumbed and dropped during the night. Some 

 of these latter, although winged, have been known later to exhibit the 

 characteristics of those shown in the illustration already referred to. 



During the period in which this fungus was epidemic among the 



