=<. 6= 
Pulverized roach appetizing to Periplaneta americana L.—-Mr. Swin— 
gle states that "In cooperation with BE. H. Siegler and Francis Munger, 
of this laboratory, a new method of feeding insecticides was tried out 
on the American roach. By grinding the body of a roach in a mortar an 
efficient attractant was obtained which could easily be mixed with the 
sample of the insecticide to be tested. By this method it was a sim- 
ple matter to feed a roach unbelievable quantities of nearly pure lead 
arsenate. A single roach could be fed enough lead arsenate to kill 
several hundred roaches. However, within a few hours, the roaches re— 
surgitated the entire quantity of poison eaten. After regurgigation 
they refused to eat more of the food, although they still seemed to be 
attracted to it. By reducing the concentration of the lead arsenate 
it was possible to minimize the regurgitation and secure a reasonable 
number of mortalities. With this in mind. several experiments were 
tried with formic, stearic, and oleic green. The insects were attracted 
to the food from a distance and would run over it, touching it here 
and there with their palpi, but in all cases would finally walk away 
without eating. There is evidently an odor or taste to the members of 
the Paris green series which can be detected by the palpi of the in-— 
sect. Food pellets were made up containing bare traces of the greens 
but in each case the poison was detected. Materials like potassium 
iodide could also be detected with ease by the roaches. It is very 
strange that lead arsenate could not be detected even when present in 
extreme concentrations while any other materials, much less poisonous, 
could be detected in minute amounts. At any rate this method of mix— 
ing ground roach with the insecticide would not work with the homologs 
of Paris green." 
of the Takoma Park laboratory, reports the conclusion for the present 
of his studies on the metabolic activity during hibernation of Carpo- 
capsa pomonella L. He summarizes the data as follows: "First, during 
the course of hibernation the larvae lost 25 per cent of their weight, 
but the water and giucose content remain practically the .same; second, 
glycogen is reduced about one-half (51 per cent) and fat about one-sev— 
enth (14 per cent); third, a substantial increase in the total nitrogen 
content (nearly 15 per cent) occurs toward the end of the hibernation 
period. The chemical changes that take place in the hibernating larvae 
are rather remarkable, especially if we remember that during the entire 
period no food is available or utilized by the larvae and that all the 
chemical changes that do occur indicate a transformation of-one sub-— 
stance from another of material stored in the tissues of the larvae 
previous to hibernation. The ultimate purpose for these chemical changes 
appears to be primarily for metamorphosis." 
BEE CULTURE 
The new bee disease in Georgia and Florida.—-A new bee disease 
resembling European foulbrood has been referred to incidentally in 
recent numbers of the Bureau Monthly Letter. This disease was first 
brought to the attention of the Bee Culture Laboratory of the Bureau 
