902 
Journal of Agricultural Research 
VoL V, No. 19 
(3) An approximation of the total leafspot area involved by Cercospora 
per sonata showed that the photosynthetic area had been decreased 35.07 
per cent. Estimations of decrease in yield of peas of from 5 to 20 per 
cent as the result of leafspot are therefore regarded as reasonable. 
(4) No correlation between the presence of certain conditions of tem¬ 
perature and moisture and the prevalence of leafspot exists, because of 
the fact that air currents and certain insects are carriers of Cercospora 
personata . 
(5) As the result of 210 glycerin exposure-plate tests at Eutaw, Ala., 
substantiated by a series at Auburn, Ala., it is concluded that Cercospora 
personata is wind borne. Seventy-eight of these 210 exposure plates gave 
positive results. At no time from August 9 to August 26 was there a 
period of maximum spore dispersal as revealed by the exposure plates. 
The maximum number of conidia entrapped on any single plate was four. 
This does not represent the true condition, since the method used in 
washing the plates failed to remove all conidia. Rains rendered the air 
temporarily free from Cercospora, and dew prevented the dispersal of 
conidia at night and in the early morning. 
(6) From an examination of 75 insects collected in five localities, of 
which 54 gave positive results, it is concluded that insects are dissemina¬ 
tors of the leafspot fungus. Four orders of insects are included in these 
positive tests: Orthoptera, represented by grasshoppers and katydids; 
Lepidoptera, by larvae of Heliothis obsoleta; Coleoptera, by lady beetles, 
blister beetles, and fireflies; and Hemiptera, by leaf hoppers. Grasshop¬ 
pers, katydids, roasting-ear worms, and blister beetles eat diseased peanut 
foliage and void conidia in their fecal discharges. A single deposit from 
a grasshopper contained 250 conidia of Cercospora personata . Another 
specimen discharged 2,500 conidia of Helminthosporium Ravenelii in a 
single deposit. Grasshoppers may also carry conidia on the surface of 
their bodies. Leaf hoppers, lady beetles, and fireflies transport conidia 
on their bodies as a result of having come in contact with diseased leaves. 
A larva of Heliothis obsoleta voided a maximum of 1,050 conidia of Cercos¬ 
pora personata . Other fungi, among which are Puccinia cassipes , Alter- 
naria sp., and Fusarium sp., were found in the fecal discharges of grass¬ 
hoppers and katydids. 
(7) Alimentation in insects does not destroy the viability of Cercos¬ 
pora personata. 
(8) Grasshoppers, because of their powers of flight, are capable of car¬ 
rying the leafspot organism considerable distances. The ineffectiveness 
of crop rotation combined with seed treatment to eliminate leafspot from 
peanut fields is very probably due to the fact that air currents and certain 
insects are agents in its dissemination. 
