July r t 1918 
True Nature of Spinach-Blight 
5i 
Bean aphis (Aphis rumdcis Linnaeus).—Should this aphis become 
abundant at a time when blight is prevalent, it will undoubtedly be an 
important factor in the transmission of the same, but the species is gen¬ 
erally abundant only during the summer months and is rarely found on 
spinach in this region. On Long Island, New York, it occurs on spinach 
grown for seed. Specimens received on July 12, 1917, on blighted 
spinach plants from Long Island were placed on healthy spinach seed¬ 
lings. Infections occurred, and positive symptoms of blight appeared 
on August 2, thus proving the ability of the species to transmit the 
disease, as well as giving a record of the occurrence of blight on Long 
Island. 
Tarnished plant bug (. Lygus pratenis Linnaeus).—Two infections 
were obtained when specimens from blighted plants were transferred to 
10 healthy spinach seedlings. This species occurs abundantly on spinach 
growing after March 20. As late-grown spinach is usually not harvested 
until April it is possible that this insect may be partially responsible for 
outbreaks of the disease at this time. In the autumn occasional speci¬ 
mens of L. pratensis have been collected on spinach as late as November 
25, but our records would not indicate that they are sufficiently abundant 
to be of importance in causing early infections of blight. 
Southern corn rootworm (adult) (Diabrotica 12-punctata Olivier).— 
This insect occasionally feeds on spinach when other preferable food is 
scarce. No infections were obtained when individuals were transferred 
from diseased to healthy spinach plants. 
Green plant bug (Nezara hilaris Say).—This species has been col¬ 
lected on spinach in October and in April. Individuals which were 
known to have fed on a diseased plant were transferred to healthy plants 
and allowed to feed on them for 48 hours. No infections resulted from 
these transfers. A few individuals of Euchisius servus Say have been 
collected on spinach, and some from a diseased plant were transferred to 
known healthy plants and allowed to feed. They gave negative results 
so far as obtaining a transmission of blight was concerned. 
Thrips tabaci Lindeman, Smynthurus hortensis Fitch, and >S. quadri - 
maculatus Ryder may occur abundantly on spinach during the fall and 
spring, but no infections were obtained when these insects were trans¬ 
ferred from diseased to healthy plants. 
OCCURRENCE OF SPINACH-BLIGHT IN OTHER STATES 
New York. —On July 14, 1917, diseased spinach plants from western 
New York were received. These showed the typical characteristics of 
blight. Virus was obtained and inoculated into 15 healthy spinach 
seedlings in a field cage. Ten healthy spinach seedlings were used as 
controls. On July 25 nine of the inoculated plants had developed symp¬ 
toms of blight, and by August 1 eight were distinctly mottled, and the 
leaves malformed. Seven of the inoculated plants died shortly after 
