. Entomology : with special reference to its biological and economic aspects. tcher. These facts by no means invalidate the general theory, butthey do show that disagreeable qualities and their associ-ated color signals are of little or no avail against some weight of evidence favors the theory of warning colora-tion in a qualified form. While conspicuous colors do notalways exempt their owners from destruction, they frequentlydo so, by advertising disagreeable attributes of one sort oranother. The evolution of warning- coloration is explained by naturalselection; in fact, we have
. Entomology : with special reference to its biological and economic aspects. tcher. These facts by no means invalidate the general theory, butthey do show that disagreeable qualities and their associ-ated color signals are of little or no avail against some weight of evidence favors the theory of warning colora-tion in a qualified form. While conspicuous colors do notalways exempt their owners from destruction, they frequentlydo so, by advertising disagreeable attributes of one sort oranother. The evolution of warning- coloration is explained by naturalselection; in fact, we have no other theory to account for colors themselves, however, must have been present beforenatural selection could begin to operate; their origin is a ques-tion quite distinct from that of their subsequent preservation. 2 24 ENTOMOLOGY Protective Mimicry.—This interesting- and highly involvedphenomenon is a special form of protective resemblance inwhich one species imitates the appearance of another and Fig. 243. // ^ ^ ^^^^^ffl 1^^ ^^^ ^^jf j/^III i»v> ^^ w IM w. B A, Anosxa plexxfpus, the model ; B, Basilarcliia architt^, the mimic. Natural size. better protected species, thereby sharing its immunity fromdestruction. Though it attains its highest development in thetropics, iiiiiiiicrv is well illustrated in temperate regions. Afamiliar example is furnished by Basilarcliia arcliippus (, B), which departs widely from the prevailing dark colora-tion of its genus to imitate the milkweed butterfly, Anosia ADAPTIVE COLORATION 225 The latter species, or model, appears to be un-molested 1)} birds, and the former species, or mimic, isthought to secure the same exemption from attack by beingmistaken for its unpalatable model. The common drone-fly,Erisfalis (Fig. 244, B) mimics a honey bee in form, size, Fig. 244.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectentomology, bookyear1
