December, '13] HIXDS: powdered arsenate OF LEAD 479 



danger in the use of powdered arsenate of lead, we would by all means 

 seek to learn the truth and to inform the public accordingly. At 

 the present time we know of no reason why anyone should hesitate 

 to use powdered arsenate of lead in preference to Paris green or any 

 other arsenical poison now commonly obtainable on the market. 



The department of entomology of the Alabama Experiment Station 

 is now making an investigation covering the use of various forms of 

 arsenate of lead with a view to finding exactly what form is most 

 effective, economical and generally satisfactory, for use with various 

 insect pests, and we believe that this work will in the future be of 

 real service, not onh' to the planters who may use these poisons but 

 to the manufacturers as well. 



THE WILT DISEASE OF GIPSY MOTH CATERPILLARS' 



By R. W. Glaser and J. W. Chapman, Bureau of Entoinologij 



Introduction 



In August, 1912, we published a paper in Science entitled: ''Studies 

 on the Wilt Disease or Flacherie of the Gipsy Moth." More exten- 

 sive observations and experiments conducted during the past year have 

 led the authors to modify some of their original views concerning this 

 disease. The work last year was carried on under rather unfavorable 

 circumstances making elaborate experiments impossible. This diffi- 

 culty was overcome through the courtesy of the Bureau of Entomology 

 who supplied us with all of the necessary help and material. 



Our observations in 1912 on the general behavior of the disease as 

 influenced by external conditions, conclusions concerning the mode 

 of infection and studies on the general pathology were on the whole 

 correct, as far as they went, but a large series of experiments per- 

 formed during the past summer have shown that we were too hasty 

 in connecting etiologically a micrococcus with the disease. 



Gyrococcus flaccidifex and the Blood Test 



We described this micro- or diplococcus last j^ear (1912) and be- 

 lieved it to be etiologically connected with the wilt disease. Since 

 then it has proved to be simply a casual intestinal parasite in nature 

 with which much of our laboratory material became infected. This 

 micrococcus was isolated in pure culture and caterpillars inoculated 

 or fed wdth it died of wilt after a comparatively short time. Our 



iThiswill be followed by a bulletin of the Bureau of Entomology in whioli this 

 disease will be treated more fully. 



