BEHAVIOUR OF APOSEMATIC SPECIES 209 



orange tips very frequently are broken, which is an un- 

 usual occurrence with butterflies, the anterior part of the 

 wing usually being the strongest (c/. supra). As has 

 been said, the lower surfaces of these butterflies are de- 

 cidedly procryptic, but it must be acknowledged that, 

 as in our English " orange-tip," the bright colours of 

 the Teracolus are more developed in the male, so that 

 sexual selection may have been a factor in producing 

 them {vide infra). 



We must return to the subject of aposemes, having 

 digressed somewhat. 



Just as cryptic insects must behave in accordance with 

 the resemblance to their surroundings, so aposematic 

 species have a behaviour in keeping with their colouring. 

 It would be of Uttle use for a gaudy, distasteful insect 

 to retreat timidly or endeavour to hide itself on approach 

 of an enemy which, only partially seeing it, might grab 

 at it and damage it fatally before the mistake was found 

 out. Everything is to be gained by flaunting the banner 

 in the face of the enemy, so that there can be no possibility 

 of a mistake. Consequently, aposematic insects are of the 

 boldest demeanour, and are the species most frequently 

 seen by the casual observer. If endeavours are made 

 to catch one, for instance a Planema butterfly, it merely 

 flits out of reach, and returns to the same spot apparently 

 unalarmed. 



A large grasshopper {Dictyophora laticincta), of family 

 Acrididae, was frequently met with on the islands fully 

 exposed on pathways : a bloated creature with heavy 

 body, whose wings are so atrophied that it cannot possibly 

 fly. So sluggish is it that it scarcely troubles to move 

 out of the way, or gives a feeble hop merely carrying it 

 for a distance about equal to the length of its own body. 

 In colour it is grey-black, and the short wings are scarlet, 

 and there is some of the same colour along the sides of 

 the fat abdomen. If persistently annoyed it will raise 



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