December, '15J LAMSON: POISONOUS EFFECTS OF ROSE CHAFER 



547 



Explanation of Plates 30 and 31 



Fig. 1. Idiocerus gemmisimulans, first stage nymph. 



Fig. 2. Idiocerus gemmisimulans, second stage nymph. 



Fig. 3. Idiocerus gemmisimulans, third stage nymph. 



Fig. 4. Idiocerus gemmisim.ulans, fourth stage nymph. 



Fig. 5. Idiocerus gemmisimulans, fifth stage nymph. 



Fig. 6. Idiocerus gemmisimulans, adult male. 



Fig. 7. Idiocerus gemmisimulans, egg. 



Fig. 8. Idiocerus gemmisimulans, cluster of eggs in position. 



Fig. 9. Idiocerus gemmisimulans, face of male. 



Fig. 10. Idiocerus gemmisimulans, wing of male. 



Fig. 11. Gonatocerus ovicenatus, male. 



Fig. 12. Gonatocerus ovicenatus, female. 



THE POISONOUS EFFECTS OF THE ROSE CHAFER UPON 



CHICKENS 



By G. H. Lamson, Jr., Storrs, Conn. 



Serious losses have occurred each year during June and early July, 

 from chickens having eaten the rose chafers {Macrodadylus suhspi- 

 nosus). These losses have often been ascribed to various causes but 

 close observations have shown that the chickens are very fond of eating 

 the insects and post mortem examinations have revealed the pres- 

 ence of many undigested rose chafers in their crops. The crops are 

 usually so full as to give the impression that death had been due to 

 a ''crop-bound" condition of the chickens. Some have also supposed 

 that these deaths were due to a mechanical injury of the crop by the 

 spines on the legs of the insects having punctured the lining of this 

 part of the digestive system while others have accounted for the death 

 of these chickens by the rose chafers having bitten the crops. 



A number of cases, some of which resulted in the loss of several 

 hundred chickens, were reported to the writer and experiments in 

 feeding rose chafers to chickens were taken up at the Storrs Agricul- 

 tural Experiment Station in 1909. 



The deaths from this diet usually occurred in from nine to twenty- 

 four hours after feeding. 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 poisoning; large doses resulted in their deaths. 

 Mature hens did not die from the poison. 



From 150 to 200 chickens have been fed either with the rose chafers 



