10 NEMATODE GALLWORM ON POTATOES, ETC., IN NEVADA. 
In figures 6,7, 8,9, and 10 are shown the results of gallworm injury 
on the peach, the grape, the willow, the fig, and cotton. These plants 
are all distinctly susceptible to gallworm injury and may serve to 
indicate the presence of this worm if it occurs abundantly in the soil. 
Figure 11 shows the enlargements on, the roots of a cowpea caused by 
the nematode. These enlargements are characteristic and need not 
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Fig. 9.—Roots of the fig, ? 
showing enlargements 
caused by the nema- 
tode gallworm. The fig 
is very susceptible to 
the attacks of this para- 
site and, though when 
the roots are severely 
Fie. 11.—Roots of the cowpea, 
showing enlargements caused 
by the gallworm. With the 
exception of one variety (the 
infested the tops may Fia. 10.—Roots of cotton, showing en- Tron cowpea) this plant is very 
continue to grow when largements caused by the gallworm. susceptible to the gallworm, 
conditions are favor- Owing to the wide prevalence of this and the use of susceptible va- 
able, in times of drought worm in the southeastern United rieties as green-manure crops 
or in cold weather the States, the aggregate annual damage in peach orchards and in rota- 
diseased plants suffer which it causes on cotton is very large, tions just preceding cotton in 
severely. (After J. C. though not generally appreciated. the South is to be avoided. 
Neal.) (After George F. Atkinson.) . (After J.C. Neal.) 
be confused with the nodules caused by the nitrogen-gathering bac-— 
teria which inhabit the roots of this plant. The nodules caused by 
the nitrogen-fixing bacteria are small and spherical and are attached 
to the side of the rootlets, while the nematode causes the swelling of 
the root itself. Figures 12 and 13 show the effect of the attack of 
the gallworm on red clover and also the worm as it is found in the roots. 
In figure 12 the enlargements on the roots are shown, while in figure 
13 the sections of the root show the presence of the gallworm larve. 
Figure 14 shows the enlargement caused by the gallworm on the roots 
[Cir. 91] 
