58 



Having- had some previous experience with an insect-destroying 

 fungus of a similar a])pearance in the destruction of quite a different 

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

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

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

 of the find, specimens of the dead fungus-covered 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-killing fungus belongs has been 

 definitely settled, various unavoidable 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 away from the light and seek dark, 

 moist places in which to die. Consequently they 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 entirely filled 

 with mycelial threads and spores of the fungus. In man}^ 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 coidd 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 dying in rather large numbers in the vicinity Avhere the fungus 

 had first l)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 they too were found to sicken 

 and die. 



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

 trichimi globuUferum, 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 the}^ failed to reach a suffi- 

 ciently moist and shad}" place shortly' became quite 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 man}' 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 



