2 IH'LLKTIX 122*, U. S. DEPARTMENT OE AGRICULTURE. 
The tests included a number of materials and methods grouped 
under the heading " Miscellaneous treatments." besides special 
studies of various substances applied in the form of paints, dusts, and 
sprays. Details of these tests are given under appropriate headings. 
In a number of cases substances were tested in small containers, 
such as jars and vials. Such tests, involving both contact and 
fumigation action on the mite, were considered so severe that failure 
to obtain satisfactory results thereby indicated with certainty that 
the materials would be inefficient in practical use in chicken houses. 
Such materials might, therefore, be classed as of no value, without 
further testing. 
In computing the degree of efficiency, in tests other than in small 
containers, it was found necessary to use somewhat arbitrary terms. 
It is next to impossible to make actual counts of the mites alive and 
dead on a roost or in a nest box, and much more so in a chicken 
house. The effect of a material can be gauged only by estimating 
the general mortality from the percentage of living and dead found 
in the more easily observed places and by observing how rapidly 
reinfestation occurs in the premises. In the latter case the season of 
the year should also be taken into account, as the mite reproduces 
more rapidly under higher temperatures. 
Many materials proved to have no value in the control of mites. 
Others listed as " inefficient " failed to reduce the mites sufficiently to 
prevent a speedy reinfestation. In some such cases it appeared that 
a major percentage of active mites were killed outright, but no 
effect was exerted on the eggs. Materials to which the term "some- 
what efficient" is applied were those in which it appeared that 60 to 
75 per cent of the mites were killed, but the residue was large enough 
to bring about a speedy reinfestation. '"Moderately efficient' 7 
materials were those which reduced the infestation greatly and 
prevented more than a comparatively small subsequent reinfestation. 
The term " efficient" was reserved for materials which killed all or 
almost all the mites, and subsequent infestation, if any appeared, was 
insignificant in proportion to the original. 
These terms apply only to single treatments. In many cases two 
or more treatments were made in the same premises. While the 
total mortality was increased thereby, the treatments were not 
progressively effective, the subsequent ones not equaling the original 
in effectiveness. Unless otherwise noted, the tests described herein 
represent single treatments. 
MISCELLANEOUS TREATMENTS. 
FUMIGATION. 
An infested roost was fumigated in a fumigatorium of ;>(>() cubic 
feet capacity for 6 hours by burning, id sawdust, 8j ounces of naph- 
thalene. A Dumber ot mites Were fumigated in a tignt container 
for 30 hours l>y burning the same quantity in carbon. Both treat- 
ments were effective. An infested nest box was treated by burning 
13 grams of pyrethrum. A chicken house was fumigated by placing 
in Bye coals on the floor 58 cubic centimeters of a preparation con- 
taining 7.5 per cent Of borax and a small quantity of pyrethrum. 
Two chicken houses were fumigated by burning respectively 1 and 1 
pounds of sulphur for 4 hours. The capacity of the houses used in 
