- Ill - 
Exposure to ultrn-violet light definitely ^.pcrep.s^a thf effecti'-'-eness of 
derris, rotenone, and deguflin as repellents. Phenothiazine had a narcotic 
effect on the beetle but vhen added to derrip decreased the effectiveness of 
derris as a repellent. The addition of fish oil or tannic acid to a derris 
suspension did not modify t\e repellent action of the material. Sodiujn- 
silicate solutions appeared to decompose derris. Derris can be readily washed 
from foliage. The action of rain in the fif>ld is believed to be one of the 
most important, if not the most important, factor limiting the effectiveness 
of derris sprays. Several materials vrere tested as stickeiB-for derris, the 
most promising being a paraffin emulsion. 
Miscellaneous tests with extract^: of petunia, carrot, devil' s-ehoestrings, 
and bittervrood showed that these materials were of little value as repellents 
against this insect. Cube resin, n-methyl phenothiazine, 2-phenyl benzo- 
thiazole, and picrasmin A and B also proved unsatisfactory as stomach poisons 
and as repellents. 
Fleming, Ba'-er^^and Koblitrky ( I39 . lUo) in I93U reported that chemically 
pure rotenone, 90 percent rotenone, and derris containing U percent of rote- 
none v/exe, ineffective as stomach poisons to third instars of the Japanese 
bfetle when added to soil at rates ranging from 5OO to 5,000 pounds per acre, 
Osburn ( 3II ) in 193^ reiDorted trials of repellents against the Japanese 
beetle. During the season of 1932 it was found tha.t the application of five 
sprays, each consisting of 1 pound of QO-porcent rotenone to 5OO gallons of 
water ,_ appreciably reduced the number of Japanese beetles on peach and apple 
trees; less concentrated sprays were less effective. In 193^ *^® fallowing 
sprays, containing 100 gallons of vrater, 01 pound and 0.2 pound of rotenone 
plus 0,1^ gallon of summer oil, 2,5 pounds and 5 pcunds of derris root ( U per- 
cent of rotenone), .„ j . . '• " t. '- r .. .-.. ..^ v . }, and 
2.5 pounds and 5 pounds of derris root (U percent of rotenone) plus O.U gallon 
af summer oil, were applied to the following varieties of fruit treesJ Apple — 
Henry Clay,_ Star, Wealthy, Stayman Vincsap, Yellow Transparent, and V7illi?.ms 
Early Red; Peach — Kale and Elbcrta. The sprays were applied at weekly inter- 
vals, except that additional sprays vrere applied immediately after heavy rains, 
not more than six applications being made. The results may be summarized ns 
follows: Derris was more repellent to the Japanese beetle than rotenone, 
rotenone with oil was more repellent than rotenone alone, derris alonre w?s 
better than rotenone and oil, vrhile derris and oil gave the b^st results. That 
is, derris and oil > derris ;. rotmone jvnd oil ' rotenone. The check trees 
were defoliated rapidly. 
The United States Department of Agriculture, Bureau of Entomology and 
Plant Quarantine (390) in I935 reported various tests with derris. Derris is 
a wea'': stomn.ch poison but has a definite reprllenny for the adult Japanese 
beetle, the repellent action apparently bring due to the rotenone and deguelin 
content. Exposure to light decreased the effectiveness of derris, and the 
material was readily washed from foliage by rain. Several materials have been 
tested as sticker and as means to prev-nt the decomposition of derris in the 
field. Oils, while very effective sticker?!, have been found to accelerate the 
decomposition of derris when spread in a thin layer on the surface of the leaf. 
The emulsified residue from rosin stills has bren found to be the cheapest and 
ino«-t effecti'i'e sticker that does not rccnl- rate the decomposition. The addi- 
tion of magnesium silicate to the spray increased the r^eriod that the material 
is effective as a repellent. Derris without a sticker appeared to bo of little 
■value in the. protection of early ripening aniDles from attack by the beetle. 
