the Edihility of certain Lcpidopterous Larvae. 473 



and once the beetle appeared to nip the lizard with its 

 mandibles, as it dropped it suddenly and went through 

 surprising contortions. 



The imago of P. rapae was eaten with apparent relish, 

 as also that of Plusia gamma. Green and greenish-brown 

 larvae of cryptic habits wei'e eaten, as also were the 

 extremely cryptic geometrid larvae of Amphidasys lettdaria 

 and Selcnia hmaria. A bee was attacked and dropped, 

 though the salamanders ate bees with impunity. The most 

 interesting results were obtained with the larvae oiBoarmia 

 rhomhoidaria. This larva was found in large numbers 

 feeding on ivy. Probably few British larvae have attained 

 to a more perfect development of cryptic form, colour and 

 habit than this species. It resembles so perfectly the 

 twigs of the ivy that it is frequently only possible to detect 

 it by the sense of touch. If thrown down it will often lie 

 perfectly straight and motionless, when it is practically 

 indistinguishable from a small piece of stick. According 

 to the general rule it would be expected that this larva 

 when detected would prove to be as palatable as hctularia, 

 lunar ia, and other similar forms. My experiments, how- 

 ever, proved that quite the opposite is the case. I was 

 interested to discover whether this unpalatability could 

 be traced to any definite secretion, such as potassium 

 hydroxide. A crushed larva gave a slight alkaline reaction 

 with litmus paper, so I boiled a considerable number of 

 the larvae and tested the filtered solution. The alkalinity 

 was, however, so slight that it seemed unnecessary to 

 pursue the examination in this direction, and it appeared 

 probable that the food-plant might be directly responsible 

 for the chemical reaction. This again proved not to be 

 the case, as the crushed shoots of ivy were found to be 

 slightly acid. 



As the larva in question will eat other plants than ivy 

 it occurred to me to try the effect of a change of food- 

 plant on its edible properties. I found that after being 

 fed on apple for from two to three da3's and onwards, the 

 distasteful properties disappeared and the apple-fed larvae 

 were eaten without any hesitation. 



I herewith append notes from my journal made at the 

 time of each experiment, in order that those interested 

 may judge of the results for themselves. 



August 29. — A salamander ate an earthworm, then a 

 bee (without apparently being stung), and then another 



1 1 2 



