V. 



Notes on Warning and Protective Colour in 

 Lepidopterous Larvae. 



IN the April number of Natural Science, Mr. George Carpenter 

 deals with the vexed question of " Colour in Insects." The 

 whole subject of animal colouration has been much debated, and as it 

 is only by means of a long series of careful experiments and close 

 observation that we can h'^pe to arrive at any clear understanding of 

 it, every particle of evidence, however small, may have some value. 

 From this point of view the following notes may not be without 

 interest. 



The experiments made by me as to palatabihty and colour- 

 relation in lepidopterous larvae were, as Mr. Carpenter correctly 

 states, entirely confirmatory of those previously conducted by Mr. 

 Poulton and others. They have been recorded in detail elsewhere 

 {Trans. Ent. Soc. Loud., 1892, pt. iii.), and I therefore give only a 

 brief sketch of them here, together with a few additional facts wiiich 

 have come under my notice since writing the above-mentioned paper. 

 Experiments as to the palatabihty of conspicuous larvae were made 

 with four species, viz., with larvae of Diloba caevideocephala, Ciicullia 

 verbasci, Acronycta psi, and Bomhyx riibi. Larvae of the two first-named 

 species were given to a tame jackdaw, which had been taken un- 

 fledged the previous year, and could never have seen any larvae 

 except those I gave him, unless some had dropped occasionally from 

 a beech tree which overhung his cage. The larvae of D. caeriileocephala 

 were taken feeding freely exposed on pear trees ; they were blue, 

 yellow, and black, very conspicuous, and not hairy. 



The bird was accustomed to take anything from my hand, and 

 would always seize and attempt to pull to pieces any object presented 

 to him, whether he was hungry or not ; he was, therefore, a good 

 subject for experiment. 



On offering him a larva he appeared very suspicious, and for a 

 long time would not take it. Then he tasted it, but dropped it 

 at once, shaking his head violently, and evidently disliking it. It 

 was tasted once more, and then left uneaten. The next day he was 

 ofifered a common smooth green larva (species unknown) and ate it 

 without hesitation. He was not very hungry on either occasion. 



