62 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
infestation became very bad a considerable amount of the older 
beet foliage had been killed by the “‘leaf-spot”’ disease (Cercospora 
beticola Sacc.) and the plants had put out a new stock of leaves. The 
Diacrisia attack, following the ‘‘leaf-spot’’ injury, made necessary 
still another crop of leaves before the beets could mature. By 
October 5 the bulk of the larve had entered winter quarters. The 
cocoons were common under weeds and many contained pups. On 
October 12 there were still a few belated larvee on the beets. 
Between October 14 and 24 a trip was made through the beet- 
growing sections of the Arkansas Valley. At Las Animas, Colo., 
about 30 miles east of Rocky Ford, the larve had been abundant 
and destructive. This place appeared to be the eastern limit of 
injury. Examinations and inquiries made at Lamar and Holly, 
Colo., and at Garden City, Kans., showed that the larve had not 
occurred in unusual numbers at those places. West and north in 
the Arkansas Valley the larvz occurred in injurious numbers as far 
as the beets were grown, i. e., into the country around Pueblo and 
Sugar City, Colo. 
As late as October 24 occasional larve still occurred on the beets 
at Rocky Ford, Colo. At this date 100 cocoons were collected from 
under boards and weeds and examined. Seventy-four contained 
live pupe, 4 contained dead pupx, in 10 were live larve, and in 12 
dead larve. Two of the live larve had the eggs of a tachinid parasite 
fastened on their backs and one of the dead larve contained a live 
tachinid larva. The other larve had evidently died either from a 
fungous disease or from natural causes. Two of the dead pupe 
were deformed and the other two had evidently died from disease. 
By October 30 the larvee had almost completely disappeared from the 
beet foliage. 
A remarkable feature of this outbreak is that the larve had so few 
natural enemies. Birds did not eat them, and with the exception of 
a few individuals which were killed by parasites and disease they 
appeared to be unmolested. 
On November 12 thousands of healthy pupz were in condition to 
pass the winter safely. If the pup are not killed by man or by 
adverse weather conditions, there is every indication that there. will 
be another outbreak of the pest during 1910. 
LIST OF PLANTS INJURED. 
During September, when the larve occurred in most noticeable 
abundance, they were found feeding on the following plants: Sugar 
beet, stock beet, table beet, rhubarb, cabbage, cauliflower, turnip, 
radish, celery, carrot, parsnip, eggplant, potato, pumpkin, squash, 
watermelon, cantaloupe, sweet’ potato, corn, lima bean, string bean, 
asparagus, pea, peanut, alfalfa, hollyhock, morning-glory, canna, 
ee 
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