4 FARMERS’ BULLETIN 1721. 
15 to 20 rose-chafers were sufficient to cause the death of a chick 1 
week old. In the case of a 10-week-old chicken, 96 undigested rose- 
chafers were counted in a post-mortem examination. An extract 
made from 40 grams of rose-chafers was injected into rabbits, which 
died in six minutes, and in one case in three and one-fourth minutes 
after the injection of 4c. c. Other rabbits were killed in proportion 
Fic, 5.—Grape cluster showing almost total destruction of young berries through feeding 
of rose-chafer. (From Johnson.) 
to the size and dose. The opinion was reached that owing to the fact 
that the insect feeds on a large number of plants, and especially on 
daisies, its body contains a neuro-toxin which affects the hearts of 
small animals, such as chickens and rabbits. 
NATURAL HISTORY AND HABITS. 
The rose-chafer, as already stated, appears early in June, the date 
varying somewhat according to locality and season. Soon after 
1 Lamson, G. H. The poisonous effects of the rose-chafer upon chickens. Jn Science, 
v. 43, no. 1100, p. 188-139. Jan. 28, 1916. 
