4 ANNUAL REPORTS OF DEPARTMENT OF 
existing in the Pacific Northwest In the Middle West and East the results 
less favorable, although sufficiently encouraging to warrant further work. The 
material, however, has certain disadvantages which must be overcome before it 
can be recommended for practical use. it is Irritating to the skin of persons 
applying the spray, and to a lesser extent to other workers In trees to which 
applications have been made. More complete Information Is Deeded also on the 
effect of phenothiazine <>n the size and color of the fruit Further work Is being 
carried on with certain forms of the so-called fixed-nicotine combinations, special 
effort being made to develop combinations thai do not leave unsightly residues 
on the fruit. 
In experiments in the Northwest with chemically treated bands to determine 
more exactly the load of hetn-napht hoi and oil needed for full effectiveness in 
that area, a load Of <>.•*'>- Ounce Of the beta-naphthol-Oil mixture per linear foot 
of 2-inch hand destroyed practically all of the worms, in the Middle West and 
Bast 0.50 ounce of the standard formula per linear foot appeared necessary to 
prevent practically all emergence during the season, in the eastern experiments 
the addition of small (plant it ies of aluminum stearaie reduced by about 20 
percent the quantity of chemical coating required. 
Practical held experiments carried on in southern Indiana with a combination 
of orchard clean-up practices and banding have confirmed previous results, and 
indicated a reduction in infestation of fully oil percent Similar experiments 
have been started at Yakima. Wash. 
Further held experiments have been carried on with numerous bait materials. 
In the Northwest the outstanding attractants have been 10 percent of molasses 
with 1 cc of pine-tar oil per quart, and 10 percent of in-own sugar with one-half 
cubic centimeter of hromostyrol per quart. In southern Indiana the pine-tar oil- 
molasses mixture also gave good results, especially early in the season. < »il of 
mace, hromostyrol. and oil of sassafras with brown-sugar solution were about 
equally effective. Although the direct control value of bait traps i- -till problem- 
atical, they continue to be of great value to orchardists in the timing of their 
spray applications. 
The extensive field experiments in utilization of the egg parasite Trichogramma 
minutum Riley, carried on at Cornelia, Ga., in cooperation with the Georgia 
State entomologist's office, and at Yakima, Wash., indicated a slight reduction 
in infestation as a result of liberations of this parasite. This reduction, how- 
ever, was not significant from either a statistical or a practical standpoint, and 
the experiments were discontinued at the close of 1935. The important eastern 
codling moth parasite Ascogaster quadridentatus Wesm. has now been colonized 
in most of the important western apple-producing sections where formerly it did 
not occur. Arrangements are being mad* 4 for the distribution to new areas of 
other parasite species, including Phanerotoma tibialis Ilald. and 
carpocapsae Cushm. Experiments with a combination of mechanical control 
measures and efforts to stimulate the activities of parasites have been started in 
West Virginia, in cooperation with the West Virginia Agricultural Experiment 
station. 
Colonies of the woolly apple aphid parasite iphelinus malt Ilald. have been 
sent to :i number of state agencies, Including those in Utah, California, Col< 
New Mexico, and Kansas, for liberation in orchards infested with the wool.y 
apple aphid. 
a project on the control of the pear thrips on pears and prunes in the Pacific 
Northwest h:is been undertaken in cooperation with the Oregon Agricultural 
Experiment Station. This insect has been causing serious damage in certain 
areas in the Northwest, and the standard spray program has not been giving 
satisfactory COnl rol. 
in tests against hibernating codling moth larvae, a 20-percent emulsion of 
pine oil alone killed .".^ percent of the larvae, whereas the addition { ^\' ] percent 
of alpha naphthylamino Increased the kill to 7.". percent, and the addition of 1 
percent of nicotine increased it to 1(H) percent A number of other materials. 
Including phenothioxin, orthodichlorobenzene, rotenone, diphenyl oxide, diphenyl 
sulphide, and ort honit roanaline. failed tO Increase the effectiveness Of pine oil 
against hibernating codling moth larvae. 
PEACH insi < n 
Major attention has Keen given to the Introduction and colonization of foreign 
and d< BtiC parasites Of lh<- oriental fruit moth. The work with bait traps for 
fruit moth control has heen curtailed and the funds used to support the work of 
distribution and recovery of parasites in the middle western areas of Infestation. 
