January 28, 1916] 



SCIENCE 



139 



in tlie loss of several hundred chickens, were 

 reported to the writer and experiments in feed- 

 ing rose chafers to chickens were taken up at 

 the Storrs Agricultural Experiment Station 

 in 1909. 



The deaths from this diet usually occurred 

 in from nine to twenty-four hours after feed- 

 ing. This led the writer to believe that un- 

 doubtedly death resulted from a cause other 

 than a mechanical injury to the crop or " crop 

 bound " condition. An extract was made from 

 crushed rose chafers and distilled water, 

 filtered, and fed to chickens in varying doses 

 with a medicine dropper and this resulted in 

 a great many deaths. Small chickens died in 

 a few hours after feeding, older chickens of 

 heavier weight when fed a small quantity of 

 the extract lived but showed signs of poison- 

 ing; large doses resulted in their deaths. 

 Mature hens did not die from the extract. 



From 150 to 200 chickens have been fed 

 either with the rose chafers or with varying 

 strengths of the extract to determine the 

 weight of the chicken killed by a certain 

 amount of poison, also to determine the age 

 limit of the chickens killed. 



The results may be summarized as follows : 

 15 to 20 rose chafers are sufficient to cause the 

 death of a chicken one week old. From 25 to 

 45 rose chafers are usually necessary to kill a 

 three-weeks-old chicken. While some nine- 

 weeks-old chickens have been killed by eating 

 rose chafers, only one ten-weeks-old chicken 

 was killed in these experiments. In the crop 

 of this chicken there were 96 undigested rose 

 chafers counted in post-mortem examinations. 



The chickens feed upon the insects raven- 

 ously, being attracted by their sprawly ap- 

 pearance and usually within an hour after 

 eating they assume a dozing attitude, later 

 leg weakness shows and the chicken usually 

 dies within twenty-four hours of having eaten 

 these insects, or begins to improve after this 

 time. 



In less than five per cent, of the deaths con- 

 vulsions occurred. Post-mortem examinations 

 showed no abnormal condition of the organs. 

 In order to exclude the possibility of arsenical 

 poisoning due to the rose chafers having fed 



upon leaves that have been sprayed, tests were 

 made by a chemist for arsenic, but no evidence 

 of arsenic was foimd. 



Intravenous injections were made in these 

 experiments, extracts for injection being made 

 from forty grams of rose chafers and sixty c.c. 

 of a salt solution having a specific gravity of 

 .9 per cent. This extract was put in a centri- 

 fuge for five minutes, the extract drawn ofi in 

 a pipette and filtered in vacuo. Three c.c. of 

 this extract were injected into a 690-gram 

 rabbit intravenously and this died in six 

 minutes. Another rabbit, weighing 1.435 

 grams, died in three and one quarter minutes 

 after an injection of four c.c. A small 610- 

 gram rabbit, when injected with two and one 

 half c.c, died in fifty-five seconds after injec- 

 tion, and a large 1,450-gram rabbit died in two 

 hours and thirty-five minutes after being in- 

 jected with two c.c. Other rabbits were in- 

 jected and killed by this extract, but further 

 work needs to be done to determine what is a 

 lethal dose for rabbits and experiments in 

 feeding rabbits per os will be taken up next 

 summer. 



As nearly as the writer can determine, the 

 rose chafers contain a neuro toxin that has an 

 effect upon the heart action of both chickens 

 and rabbits and is excessively dangerous as 

 a food for chickens. 



Owing to the fact that the insect feeds upon 

 such a large number of plants, particularly on 

 daisies, it seems essential that chickens be kept 

 in mowed fields and away from yards having 

 grape vines and any flowering shrubs during 

 the month when the rose chafers are about, 

 especially during years when rose chafers are 

 particularly abundant. 



George H. Lamson, Jr. 



Conn. AoEictrLTUEAL College, 

 Stores, Conn. 



THE AMERICAN SOCIETY OF ZOOLO- 

 GISTS 



The American Society of Zoologists held its 

 thirteenth annual meeting jointly with Section F 

 and in affiliation with the American Society of 

 Naturalists, December 28, 29 and 30, 1915, in 

 Townshend Hall, Ohio State University, Colum- 

 bus, Ohio. 



