the Edibility of certain Lepidopterous Larvae. 473 



^nd once the beetle appeared to nip the lizard with its 

 mandibles, as it dropped it suddenly and went throucrh 

 surprising contortions. ° 



The im^go oiRrapae was eaten with apparent relisli, 

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

 larvae ot cryptic habits were eaten, as also were the 

 extremely cryptic geometrid larvae of Amphidasy, hetularia 

 and Sclcma Immria. A bee was attacked and dropped, 

 though the salamanders ate bees witli impunity The most 

 interesting results were obtained with the larvae oiBoarmia 

 Thomloidarm. 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 

 perlectly 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 hetularia 

 lunarta, 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 alkalinitv 

 was. however, so slight that it seemed unnecessary to 



^"TJi l^^'T'?^'?'' ^" ^^"' direction, and it appeared 

 probable that the food-plant might be directly responsible 

 ior 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 r>lants than ivy 

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

 plant on IS edible properties. I found that Sfter being 

 fed on apple for from two to three days and onwards, th? 

 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 



112 



