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Phenacoccus gos sypii T, & C,, the Mexican mealybug 
IJeisvan der ( 204 ) in 1935 reported that a product containing 1 per- 
cent cf rotenone at 1:200 plus Penetrol at ls200 killed 31 percent of P, 
£5lS. s 2P.ii on greenhouse chrysanthemums. The jest control, 91 percent, was 
obtained with Lethane No, 420 at 1:400 plus Penetrol at 1:200. 
Richardson ( 252 ) in 193-5 reported on the insecticidal control of 
— .%PJ'^l r P23- on greenhouse chrysanthemums. A derris dust containing 4 per- 
cent cf rotenone killed 10,5 percent of the nymphs, pupae, and adults, and 
7 percent cf the eggs-. A derris extract diluted to contain rotenone 
1:10,000 by weight plus other derris extractives was mixed with potassium- 
ccconut-oil soap (0.33 percent dry soap o^ weight). This spray hilled 
,5 percent of the nymphs, pupae, and adult:;. The same derris extract 
plus C ,6 percent by volume of a sulfonated petroleum oil [Fsr.etrol?] 
killed 15,5 percent of the nymphs, pupae, and adults, Tnc Pest control 
(97«3 percent) was obtained by a 10-percent emulsion of kerosene. 
■Pspudo coccus brevipes (Ckll.), the pineapple mealybug 
"hatarabe ( 501- ) in 1936 reported that derris sprays have proved of 
son.- value in the control of P. brevipes on pineapples in Formosa, 
Pseudoccccu ?' dtri (Risso), the citrus meaJLybug.j a greenhouse mealybug 
Mclndoo, Sievers, and Abbott (IPS) in 1919 reported that derris 
applied r~. a dust was of nc value against this nealybug, Derris has e,iven 
irregular and rather unsatisfactory results. — hope (176) in 1924. 
Rotenone suspended in water ( 1:250) killed only 25 percent and a 
dust of 2 parts of rotenone and 95 parts cf diatomaceous earth killed 
none. — Davidson (65; in 1930. Rotenone in oil was highly effective. — 
Turner ( 271 ) in lW5Z m 
A ro ten one-pyre thrum spray containing 0.75 percent of rotenone 
and 1.8 percent of pyrethrihs at 1:200 reduced the infestation 74 percent, 
as compared with a S9-percent reduction obtained by Lethane Ho, 420 at 
1:800 plus soap 1:250. Three applications were made at intervals of 1 weeS 
on these ciealybugs infesting colons. — Neiswander (204; in 1S35. 
Ps eu cococcvs c c;.is t och i (Kuwv), the Cons took mealybug 
P.ivnay ( 253 ) in July 1939 reported on the control -of P. corns tocki 
on citrus in Palestine. A proprietary insecticide containing derris and 
pyrethrum gave an unsatisfactory raortalityj so did also another brand 
containing derris alone vh.cn used at the rate of 1:500, as directed by 
th e manu fa c tur er s , 
Pseudoc cccus zp> + 
Rotenone sprays were ineffective agairst a mealybug on parrotfeather 
( Myriophyllura ) , The rotenone suspension was prepared by aiding a solution 
of 0,2 gm, rotenone in 5 ec, benzene and 95 cc. Penetrol to r.ater to make a 
concentration of rotenone 1:100,000 olus Penetrol 1:200. — Darley (62) in 
1931. ' 
^MMBMBt. 
