78 INSECT LIFE v 



In Coleoptera of the second category — those where 

 the gangHa of the thorax are distant one from 

 another — the effect of ammonia is quite different. 

 Those which show themselves least vulnerable are 

 the Caraboidea. A puncture which would instantly 

 have annihilated motion in the large Scarabaeus sacer, 

 in the middle size Caraboidea only causes violent, 

 disordered convulsions. By degrees the creature 

 quiets down, and after some hours' rest resumes its 

 habitual movements as if nothing had happened to 

 it. If the experiment be repeated on it twice, thrice, 

 even four times, the results are the same, until the 

 wound becomes too serious, and it dies outright, 

 as is proved by the drying up and putrefaction 

 which soon follow. 



The Melasomes and the Longicorns are more 

 sensitive to the action of ammonia. The injection 

 of a small corrosive drop quickly renders them 

 motionless, and after some twitching they seem 

 dead. But the paralysis which would have per- 

 sisted in Weevils, Scarabids, and Buprestids is but 

 momentary. Before long motion reappears as 

 energetic as before. It is only when the dose of 

 ammonia is of a certain strength that movement 

 does not reappear. But then the creature is really 

 dead, and putrefaction rapidly comes on. It is 

 then impossible to cause complete and persistent 

 paralysis in Coleoptera with ganglia far apart 

 by the means so efficacious in those with ganglia 

 near together. At the utmost one can only 

 obtain momentary paralysis, which passes quickly 

 away. The demonstration is decisive. Cerceris 

 which prey on Coleoptera conform in their 



