68 



lutnually aphis feeders, hut I foiiiid (|iiite a iiimiher at Ttlhuiy, 

 Avhich were ohserved in several iiistanees feeding on the Coh^rado 

 j)()tat() heeth''s eggs, devouring them most greedily;, and I can not 

 lielp thinking that they did nnieh of the work in getting rid of the 

 enemy. The eggs of this ladybird were deposited on the potatoes 

 and were sent in, in many instances, as Colorado potato beetle eggs. 

 They certainly i)resent a general rough likeness, but can at once be 

 told by their smaller size and paler yellow hue. The pupa^ of this 

 beneficial insect also bear a slight resemblance to those of the potato 

 "bug" and have frequently been sent in as such. They are very 

 much smaller in size, however, and could not be mistaken b}^ an 

 expert. 



AN EXPERIENCE WITH HYDROCYANIC-ACID GAS AS A RIMEDY 

 FOR THE CIGARETTE BEETLE IN DWELLINGS. 



By F. II. Chittenden juuI F. ('. I'katt. 



During the first week of September, IDO-f, tAvo persons residing in 

 the northeast section of Washington, 1). C, complained of injury 

 to furniture, rugs, and tapestry in their dwelling houses, sul)mitting 

 specimens of the larva and adult of the cigarette beetle {Lasiodernid 

 serricorme Fab.) as the cause of their troubles. The first house- 

 holder was very fearful lest the insects would spread from the only 

 room infested to others, includir.g one containing a valuable library; 

 and the other, a lady, Avas in an exceedingly nervous condition, 

 brought about through her ineji'ectual struggles to evict the '"" bugs " 

 from her domicile. Gasoline, benzine, " black flag, ' and various 

 other insecticides, including formaldehyde, had been used without 

 aA^ail, as had also red pepper. The insects were believed, and with 

 reason, to have fed and multiplied on the last-mentioned substance. 



As no experiments had hitherto been made with the hydrocyanic- 

 acid gas treatment for this insect, experiments were instituted in the 

 second house. A visit to this house showed injury plainly visible on 

 the upholstered furniture, and the edges of a carpet were frayed. 

 Numbers of beetles and their larvtv were observed, the last in cells 

 preparatory to pupation. 



ExperimeHf Xo. 1. — The gas Avas used at the usual strength — 1 

 ounce of cyanide of potash to 100 cubic feet of space, the doors and 

 windoAvs being quite securely closed. The exposure Avas seventeen 

 hours. Upon aerating the folloAving morning many beetles Avere 

 found aj^parently dead on the floor and Avere SAvept up and kept in 

 a box to ascertain if they might revive. All died, hoAvever, and the 

 result was looked ui^on as satisfactory. 



Experiment No. 2. — About tAvo Aveeks later more adults Avere 

 noticed about the house, and as they continued to accumulate notice 



