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body louse than sodium fluoride, the standard treatment* A 3-percent 
DDT concentration (Gesarol A-3) was not so effective as sodium fluoride. 
The "DDT did not protect the bird from remf estation after 2 or 3 weeks, 
which is the approximate life cycle of the louse. Where all birds of 
a flock were treated, both the 3 percent DDT and the sodium fluoride 
seemed to give fairly effective control of lice. --Parker (287 ) . 
Triohodectidae 
Bovicola bovis (L») , the cattle biting-louse 
Three yearling steers heavily infested with lice were treated with 
a 10 percent DDT-pyrophyllite dust. In 24 hours all the lice had been 
destroyed; 3 weeks later a light infestation of recently hatched lice 
was observed and after 5 weeks the infestation had disappeared complete- 
ly.— Munro and Knapp (269 ) • 
Trichodectes pilosum Giebel 
Trichodectes scalaris Nitzsoh 
DDT is a contact poison.--Domen.joz (135 ) . 
THYSANOPTERA 
Thripidae 
Frankliniella fusoa (Hinds) , the tobacco thrips 
At Beltsville, Md., seven applications of a 2 percent DDT-pyrophyllite 
dust were made at 3- to 8-day intervals to one series of plots, eight 
applications of a spray containiiag 0.66 percent of DDT, obtained by mix- 
ing a 10 percent DDT-pyrophyllite dust with water and a small percentage 
of spreader, at 4- to 6- day intervals to another series, and eight appli- 
cations of an aerosol containing 10 percent of DDT, at 4- to 6-day inter- 
vals, to a third series. Good control of the thrips and decided increases 
in yield resulted from all these treatments, with no evidence of injury 
to the plants*— Packard (285 ) . 
See Thrips tabaci .— Loft in (247 ) • 
Frankliniella helianthi (Moult.), a flower thrips 
There was some indication that 1.2 percent of DDT m oil applied 
as a vapo-apray was effective against thrips on peas. — Lange (241). 
