182 A NATURALIST IN BORNEO 



situations unprotected by horny egg-shells. Without 

 some form of protection they would be exposed to all 

 sorts of dangers, hence that they should be enclosed 

 in a special covering is only natural. That the protec- 

 tion is not absolute is certain, for Mr. Muir observed a 

 small Hymenopterous parasite depositing her eggs in 

 those of an individual Aspidomorpha puncticosta [Trans. 

 Ent. Soc., 1904, p. 18], as fast as they were being laid. 

 But then we know that none of the multifarious pro- 

 tective devices of Nature are absolutely successful. If 

 there were no destruction of individuals of any given 

 species we should be overrun by countless hordes of 

 them in a very short space of time. 



The shields of excrementitious matter and chains of 

 moulted skins play a double role. The larvae and the 

 newly formed pupae have the habit of twitching or 

 flicking up and down these appendages whenever irri- 

 tated, and these movements might be quite sufficient 

 to drive away any but the most persistent of parasitic 

 enemies. But I think that they serve also to render 

 the larvae and pupae conspicuous objects. The adult 

 beetles are certainly very distasteful creatures. Most of 

 them are abundant, they are gaudily coloured, and some 

 species are mimicked by other insects. Prioptera %-punc- 

 tata, at any rate, exudes an acrid fluid when handled. 

 These are characteristic features of nauseous species. 

 I have not the slightest reason to doubt that the larvae 

 are equally distasteful, and the necessity for advertising 

 their distastefulness is urgent. The larvae of Aspido- 

 morpha miliaris are conspicuous enough objects, being 

 white, black-spotted creatures, and this conspicuousness 

 is accentuated by their habit of bunching together when 

 at rest, as well as when feeding. The pupae, although 



