body. he insects were caged with diseased plants or fed leaves 
painted with spores. The fecal pellets were sterilized externally 
and then cultured. As a summary of the studies concerning wilt and 
its viability through the insect stomach, it may be stated that—- 
"(1) Certain insects may ingest wilt fungus and pass it through 
their bodies in a viable state. Such insects include: The red-legged 
erasshopper (Melanoplus femur-rubrum DeG. ), the differential grass-— 
hopper (Melanoplus diffe erentialis lis Thos .), the American grasshopper 
(Schistocerca amer americana Drury), and other miscellaneous grasshoppers; 
the larval stages of the cotton leaf worm (Alabama argillacea Hbn.), 
the fall armyworm MC bereen key frugiperda S.&A.), the yellow-striped 
army worm (Prodenia a ornithogalli Guen.), and the boll weevil (Anthon- 
omus grandis is Boh.): waite grubs including Phyllophaga crassissima 
(Blanch.); the larval stage of Ataxia crypta (Say); and the soil— 
animal organisms. Of the insects mentioned, some are vigorous flyers 
and may spread fungus organisms in this manner. Other forms, as 
larvae, would not appreciably affect distribution of the Ccisease. 
"(2) The fungus organisms. seldom remain within the insect body 
in a viable state until the formation of the imago. Evidence to date 
indicates that the time period during which the fungus is exposed to 
alimentary fiuids is an extremely short one." 
In the experiments testing the carrying of the wilt spores mechan— 
ically on their appendages, all but one of the species of insects 
tested enla spider were positive. Work begun last season to estab— 
lish the possible relationship of certain insects to Texas root—rot 
fungus indicated that insects did not transport the causative fungus 
in a viable state. This season's work corroborated last year's ree 
sults for-- 
"(1) No sim mele instance of insects and other organisms carrying 
or disseminating viable Phymatotrichum material has yet been obtained, 
"(2) Certain insects which feed on the fungitic hyphal strands 
render them nonviable, alimentary fluids seemingly having a lethal 
effect. 
"(3) Certain insects have been observed to feed upon the various 
stages of the fungus of Texas root rot in nature, reducing the ine 
fective element in the soil which would reinfect plants during subse— 
quent years. This function is considered by the writer, however, to 
be a minor one. It is doubted that soil animals would ever act in 
this canacity to the extent of clearing up root-rot areas. Sucha 
conclusion is based on what has been observed regarding habits and 
abundance of organisms in the soil, as compared with the abundance and 
habits of the fungus in the same area. Where rot areas recover the 
role of soil organisms is regarded as perhaps a contributing factor but 
never as a causative one, 
bese © 
en ee 
