BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 69 
In Utah the tomato fruitworm infestation was of such a nature 
that no definite conclusions could be drawn from the results obtained. 
In Ohio, in the small-scale comparative-toxicity tests, indications 
are that the particular calcium arsenate used undiluted and a syn- 
thetic cryolite-talc mixture containing 70 percent of sodium fluo- 
aluminate had about the same toxicity to the tomato fruitworm. 
An undiluted domestic cryolite, diluted domestic, imported synthetic, 
and natural cryolites containing 70 percent of sodium fluoaluminate, 
and a white corn-meal bait containing 1 part of cryolite to 10 parts 
of the corn meal gave fair control as compared with 70 percent wormy 
fruit in the check plots. These plots were artificially infested. 
PEA WEEVIL 
Investigations on the seasonal habits, hibernation, and control of 
the pea weevil as a pest of dried peas, peas grown for processing, 
and Austrian peas Avere conducted in Idaho, Washington, and Oregon 
in cooperation with these States. Encouraged by the success the 
green-pea growers had in control of the weevil with rotenone-bearing 
dust, a method developed by cooperative work of the State and 
Federal entomologists, the growers of seed peas attempted for the 
first time to control the pea weevil in their plantings. Over the 
Palouse area approximately 100 tons of dust materials were used 
to treat about 31 percent of the crop. The average infestation on 
all dusted fields was 5.2 percent as opposed to 11.3 percent in undusted 
fields. 
In the Blue Mountain region, where the peas are grown mostly 
for processing, the large-scale use of dust materials containing from 
three-fourths to 1 percent of rotenone resulted for the third con- 
secutive year in satisfactory weevil control. During these 3 years 
only a small quantity of peas has been eliminated from the cannery 
pack because of weevil damage. The fact that this control measure 
is feasible and practical is now well established. However, the num- 
ber of applications of the dust and their timing vary seasonally 
and geographically and are dependent on the weevil populations 
present. The date of the weevil influx to the fields from hibernation 
and the accompanying meteorological conditions and the actual timing 
and number of dust applications will have to be determined for each 
area and each season by competent observers. 
Further information has been secured on the amount of damage 
to peas caused by the dusting machinery. The greatest damage 
(approximately 4 percent) followed the use of a duster with a 40- 
foot boom attached to a crawler-type tractor with 8-inch treads. 
The least damage (approximately 2 percent) was done by a horse- 
drawn duster — a two-wheeled affair having a 40-foot boom. It was 
also determined that a light truck driven over the pea fields when 
these were muddy did more damage than a dual -wheel truck on a 
dry field. 
Records of emergence of the weevils from hibernation quarters 
showed that in the Walla Walla area the weevils emerged over a 
period of 117 days, that is, from March 29 to July although the 
greatest emergence occurred in May and June, 61 percent of the total 
appearing in the fields in May. In the locations that were cooler 
becau.se of higher elevations the emergence proceeded much more 
