of this work has been in the hands of Mr. Samuel Henshaw, of Boston, 

 for the past two years, and the first part, just now being printed, com- 

 prises the writings of B. D. Walsh and 0. V. Riley. 



Bulletin on Root-knot Disease in Florida. — This bulletin, mentioned ill 



our Special Xotes in the last number of Insect Life, has been delayed 

 for the plates, which the printer could not have executed until after 

 July 1. We hope soon, however, to hare it ready for distribution. 



ARSENICAL POISONS FOR THE PLUM AND PEACH CURCULIO. 



By S. A. Forbes. 



The following report of results of my recent experimental work on the 

 common peach curculio is intended to correct and complete a reporters 

 summary of remarks made in August, 188S, at a meeting of the Cen- 

 tral Illinois Horticultural Society, at Champaign, as republished in the 

 last Beport of the U. S. Entomologist, page 75. The experiments there 

 alluded to were not generalized by me, but were described as merely 

 preliminary to a much more elaborate series which I have since carried 

 through. 



The object of these experiments has been to ascertain some details of 

 the food and feediug habits of the curculio and to test its sensibility to 

 arsenical poisons when distributed on the trees which the insect fre- 

 quents. In the case of the peach it was important also to find what 

 amount of these poisons the leaves might receive without marked injury. 



FEEDING EXPERIMENTS. 



June 15, 1888, plum curculios confined with plum leaves. June 1G, 

 one observed making a deep, sharp, oblong excavation in the midrib; 

 similar work on other midribs, petioles, and stems. Beetles also seen 

 gnawing the surfaces of the leaves, especially the fresher terminal ones. 

 Leaves removed aud green plums substituted. June 10, plums pep- 

 pered with holes, some containing eggs, others not. July 2, fresh lot of 

 beetles imprisoned with both leaves and green plums. The next day 

 both had been eaten, the plums perhaps the more freely. 



Several examples taken April 14, 1889, before peach trees were in 

 bloom, were proven by dissection to have last fed on dead vegetation, as 

 shown by the absence of chlorophyl and the presence of some of the 

 fungi of decomposition. Curculios confined April 19, with both dead 

 and living peach leaves, fed only on the latter, not having touched the 

 dead leaves at the end of three days. Peach blossoms being placed in 

 the cage, with fresh leaves also, April 22, both were freely eaten at once, 

 the blossoms being, however, evidently preferred. Both calyx and 



