Smiley John T
Department of Ecology and Evolutionary Biology, University of California at Irvine, 92717, Irvine, CA, USA.
Oecologia. 1985 Mar;65(4):580-583. doi: 10.1007/BF00379676.
The association between heliconiine butterflies and Passion flower vines is composed of three or more subassociations, in which each Heliconius species group feeds on a different Passiflora subgenus. The relationships are consistent with the adaptive zone hypothesis of Ehrlich and Raven, which would suggest that (1) species of the subgenus Plectostemma proliferated as a result of chemical barriers to herbivory, which created a herbivore-free adaptive zone in which speciation and diversification took place, and (2) species of the H. erato-charitonia group overcame these barriers and entered a competitor-free adaptive zone, in which they proliferated and speciated with those plants as hosts. The hypothesis that plant secondary chemicals were responsible for creating such barriers to herbivory was tested using heliconiine species as bioassays, in which reduced growth rates indicated presence of chemical barriers to feeding. Contrary to expectation, plants of the subgenus Plectostemma showed little or no chemical defense against any species of heliconiine caterpillar. In contrast many plants of the "primitive" subgenus Granadilla possessed significant chemical barriers against herbivory by heliconiine larvae, excepting those species in the H. numata-melpomene species group. I concluded that chemical barriers to feeding were not responsible for proliferation and diversification in the subgenus Plectostemma, nor did chemicals create a competitor-free "adaptive zone" in which the H. erato-charitonia species-group could proliferate and speciate. Chemical barriers may have been important in the evolution of the subgenus Granadilla-heliconiine association. I suggest that plant allelochemics are only one of many possible barriers to herbivory which can help create "adaptive zones" for plants and their herbivores, and that the patterns of butterfly foodplant specialization discussed by Ehrlich and Raven (1964) are not necessarily the result of biochemical adaptation and counteradaptation.
赫利孔亚科蝴蝶与西番莲属藤蔓植物之间的关联由三个或更多的亚关联组成，其中每个红带袖蝶物种群以不同的西番莲亚属为食。这些关系与埃利希和雷文的适应带假说一致，该假说表明：（1）褶蕊西番莲亚属的物种由于对食草动物的化学屏障而大量繁殖，这创造了一个无食草动物的适应带，物种形成和多样化在其中发生；（2）红带袖蝶-查氏袖蝶组的物种克服了这些屏障，进入了一个无竞争者的适应带，在这个适应带中，它们以这些植物为宿主进行繁殖和物种形成。使用赫利孔亚科物种作为生物测定法，对植物次生化学物质导致这种食草动物屏障的假说进行了测试，生长速率降低表明存在摄食的化学屏障。与预期相反，褶蕊西番莲亚属的植物对任何赫利孔亚科毛虫物种几乎没有或没有化学防御。相比之下，“原始”的西番莲亚属的许多植物对赫利孔亚科幼虫的食草行为具有显著的化学屏障，除了纳马塔袖蝶-美神袖蝶物种组中的那些物种。我得出结论，摄食的化学屏障不是褶蕊西番莲亚属物种增殖和多样化的原因，化学物质也没有创造一个无竞争者的“适应带”，使红带袖蝶-查氏袖蝶物种组能够增殖和物种形成。化学屏障可能在西番莲亚属-赫利孔亚科关联的进化中很重要。我认为植物异种化学物质只是众多可能的食草动物屏障之一，这些屏障可以帮助为植物及其食草动物创造“适应带”，并且埃利希和雷文（1964年）讨论的蝴蝶食草植物特化模式不一定是生化适应和反适应的结果。
