80 
‘Sodium fluoride dip for chickens effective for a month.—-Reporting 
on investigations of the chicken head louse (Linevrus heterographus Nitz. ),. 
Harold S. Peters, Takoma Park, Md., says: "On August 30 several chickens 
were dipped-in a solution of sodium fluoride as recommended for louse 
eradication. Ten days later, in an effort to remove any sodium fluoride 
remaining in the feathers, one of these chickens was dipped in plain 
water. Two, three, and four weeks after the original sodium fluoride dip- 
ping, lice were placed on the chickens and promptly died, showing that this 
dust was effective for at least a month, even on the chicken that was 
dipped in water." 
Parasite of brown dog tick active in Texas.--H. 0. Schroeder, 
Brownsville, Tex., reports that "One of the heaviest infestations of the 
brown dog tick (Rhipicephalus sanguineus Latr,) ever to come under my 
observation has been almost completely wiped out, owing mainly to the 
activity of the tick parasite Hunterellus hookeri How., which occurs lo~ 
cally in southern Texas. * * * a deg and the premises to which it is 
confined had been heavily infested for almost two years before the para- 
Site made its appearance. After less than 6 months' activity the para- 
Site has reduced the infestation to a point where it no longer consti-~ 
tutes a problem. Since the flight range of the parasite is not very: great, 
it must depend largely on being carried to new infestations by the dog 
on which its nymphal host is feeding. For this reason ticks may flourish 
within a few blocks of the place where the parasite is active. This 
is also borne out by the fact that the parasite was collected about four 
blocks from the infestation in question more than a year before the in- 
festation made its appearance there." 
and assistants, "of the waters in which Gambusia patruelis has been placed 
during the past two years. It was especially interesting to learn that 
the flooding of the Columbia River across the island on which the in- 
Sects were originally placed only scattered them to every pond and slough 
on the island. Ponds located at a distance of a mile upstream-and 3 
miles downstream on Hayden Island are now well stocked with this mosqui- 
to-destroying top minnow and it seems to be reproducing very satisfac-— 
torily, notwithstanding the numbers of predacious fish associated. The 
State fish and game warden has reported that he has taken these minnows 
while seining on Sauvies Island, a distance of some 6 miles from where 
they were originally planted. In order to give these minnows a maximum 
amount of protection, we have seined as many of the predacious fishes as 
possible from the pond on Hayden Island where G. patruelis was first 
introduced. Thousands of small bass and perch were removed. Stomachs 
of several of these were examined and practically. all. contained one or 
two specimens of Gambusia." j 
Work of botflies in tongues of horses.--R. W. Wells and E. F. 
Knipling, Galesburg, I1ll., who are engaged in studies of Gastrophilus 
Spp., report that "On September 23 at Rockford, Tll., we made examination 
of many horses being slaughtered there. Nearly all of the tongues showed 
