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Extracts from pine needles were repellent to the Japanese ceetle.-- 
Metzger and Grant (277). 
PINUS STROBUS L. White pine. 
PINUS SYLVESTRIS L. Scotch pine. 
Water extracts of the needles of the white pine killed only 10 
percent of the mosquito larvae tested and acetone extracts of the needles 
of the Scotch pine killed 25 percent.— Hart z ell and Wilcoxon ( 188 )« 
PINUS VIRGINIA Mill. Scrub pine. 
THUJA OCCIDENTALIS L. Arborvitae. 
Extracts from these plants were not repellent to the Japanese 
beetle*— Metzger and Grant (277) . 
Water extracts of the leaves killed only 25 percent of the mosquito 
larvae tested. — Hartzell and Wilcoxon (1 88) • 
TSUGA CANADENSIS (L.) Carr. Hemlock. Hemlock spruce. 
Oil of hemlock, whioh is probably obtained from this and related 
species, exhibited good repellent' action against the screwworm for 1 or 
2 days only.—Parman and coworkers ( 302 ) • 
Extracts were not repellent to the Japanese beetle.— Metzger and 
Grant (277). 
Water extracts of hemlock needles killed only 10 percent of the 
mosquito larvae tested.— Hartzell and Wilcoxon ( 188 ) . 
PIPERACEAE 
(Pepper Family) 
PIPER ADUNCUM L. 
This plant was used in Haiti as an insecticide, particularly a- 
gainst ants in seed beds.— Roark ( 332 , p. 33). 
PIPER ALBUM Vahl. White pepper. 
This pepper (10 percent in flour) had no effect on the caterpillars 
of Prodenia litura (F.) .— DeBussy (76). 
PIPER CUBEBA L. f. Cubeb pepper. 
Oil of cubeb was moderately repellent to the oriental cockroach. — 
Cole (101). 
