SUGGESTIONS AS TO THE MEANING OF THE SHAPES 



AND COLOURS OF THE MEMBRACID^, IN THE 



STRUGGLE FOR EXISTENCE 



In studying the meaning and use of insect colour and form it is deeply interesting 

 to compare broadly the two great divisions of the Rhynchota. The Heteroptera 

 (Hemiptera) are obviously, as a whole, a specially pi'otected group, commonly 

 defended by taste or smell from large numbers of insect-eating animals. Warning 

 or aposematic colours and patterns abound among them, while their movements are 

 such as to promote the conspicuous effect of strongly contrasted tints. Groups of 

 species in the same locality often possess similar aposematic colours, thus enabling 

 tlieir young and inexperienced enemies to learn and remember the appearance of 

 unpalatable forms, with a comparatively small waste of life. Such resemblances are 

 often spoken of as Mlillerian Mimicry, after the naturalist who first suggested the 

 benefits which arise from facilitating the education of foes. They may also be 

 called by the more descriptive title "Common Warning," or " Synaposematic " 

 colours. For it is clear that in such cases we have to do with the useful possession 

 of warning colours in common rather than with the benefits conferred by " Protective 

 Mimicry " (Pseudaposematic colours) as defined by H. W. Bates. By these latter 

 resemblances a rare, much persecuted, palatable form is believed to be mistaken by 

 enemies for an abundant species, well known and avoided because of some special 

 mode of defence. Good examples of S. African Heteroptera with common 

 warning colours have recently been described and figured by Mr. Guy A. K. Marshall 

 {Trans. Ent. Soc. Loud., 1902, p. 537). 



When we find the Heteroptera resembling specially protected insects of other 

 Orders, such as the conspicuous distasteful groups of Coleoptera ; the Li/ciclcB (I.e. 

 p. 515), the Canf/iarhhr (p. 518), the Cocci ncU'uUc (p. 5.2u), or the aggressive 



