Aphids do not attend to leaf colour as visual signal, but to the handicap of reproductive investment.

摘要: The evolution of visual warning signals is well known in animals but has received scant attention plants. coevolutionary hypothesis the most influential on plants proposing that red and yellow leaf colours autumn signal defensive strength to herbivores. So far, evidence support hypothesis, which assumes a origin autumnal colours, correlative open alternative explanations. We therefore tested experimentally by colouring leaves either or green same-aged mountain ash (Sorbus aucuparia) individuals. monitored response winged aphids colour using insect glue branches with natural artificial each individual. In contrast prediction aphid numbers did not differ between individuals leaves. Likewise, at within-plant level, colonize preferentially. However, we suggest emitted because colonized hosts non-randomly. found strong positive correlation fruit production, suggesting an allocation trade-off investment plant defence reproduction. Our study demonstrates use cues host selection, probably volatiles, they colour.