BUREAU OF ENTOMOLOGY. 519 



A miniber of other insects was studied, especially the cabbage 

 aphis, the cucumber beetles, the garden webworm, and the sugar-beet 

 webwornr, and all were controlled by appropriate sprays. 



The blister beetles did considerable damage to eggplant, beets, and 

 potatoes. One application of arsenate of lead, 3 pounds to .50 gallons 

 of water, checked their ravages. In five days after spraying not a 

 living beetle was to be found in the field. 



INVESTIGATIONS IN CALIFORNIA. 



The principal work in California was conducted on the beet root 

 aphis, the bean thrips, the celery leaf-tyer, and the strawberry white 

 fly. The full life history of the beet root-aphis was worked out. 



The bean thrips was the subject of an especial investigation. Its 

 life history and different food plants were studied, and it was found 

 that it is subject in one locality to attack by a very minute parasite. 

 This is the first record of a hymenopterous parasite attacking any 

 species of thrips, and it may be that the discovery will be one of 

 importance if the parasite can be reared in numbers and induced to 

 attack other species of thrips, as the pear thrips or the orange 

 thrips. 



The strawberry white fly was discovered late in September, causing 

 extensive damage to strawberries in the San Gabriel Valley. This is 

 the first record of this insect in California, and it has evidently been 

 introduced into the State on nursery stock ; in fact, in a shipment of 

 four crates by express from Tennessee that was examined, the plants 

 were found to be infested with the larva? and pupae of this insect. 

 Since that time it has been found over almost the entire State. It 

 seems to breed continuously throughout the season in California, 

 and for this reason it is likely to become a more serious pest in Cali- 

 fornia than in the East. Experiments showed that where plants are 

 fumigated with hydrocyanic- acid gas before they are set out they 

 can be freed from the pest. 



The most serious attacks upon the sugar beet in southern Cali- 

 fornia were by cutworms. In this part of the State alone over 1,000 

 acres had to be replanted. It was shown that where the first plant- 

 ing had been destroyed the second planting could be protected by the 

 use of drj' poisoned bait at a cost of from 40 to 50 cents per acre. 

 If the attack is noticed in time the beets can be protected from in- 

 jury by cutworms by the use of some bait at a cost of not over $1.50 

 per acre, while to replant represents an outlay of fully $5 to the acre. 

 Farther north another agent with headquarters at Sacramento began 

 work in January, 1911, but his work so far has been only preliminary. 



INVESTIGATIONS AT ROCKY FORD, COLO. 



Beginning with March, 1911, an agent was placed again at Roclcy 

 Ford, Colo., and began work upon the beet webworm, the beet army 

 worm, the so-called alkali bug, and the onion thrips. The extensive 

 damage to sugar beets, cantaloupes, beans, and other crops during 

 1910 by grasshoppers also led to work upon these insects. Studies 

 have been begun upon the flea-beetles damaging sugar beets and 

 upon the sugar-beet leafhoppers. 



