EPORTS by investigators in recent years indicate that substantial amounts of allelic polymorphism are often maintained in plant populations that exhibit various levels of outcrossing. The reason for this phenomenon is an important consideration in evolutionary theory, particularly for those organisms that exhibit a high degree of self-pollination (where the mating system would seem to impose a ...

Leaf-cutting ants (LCAs) are polyphagous, yet highly selective herbivores. The factors that govern their selection of food plants, however, remain poorly understood. We hypothesized that the induction of anti-herbivore defences by attacked food plants, which are toxic to either ants or their mutualistic fungus, should significantly affect the ants' foraging behaviour. To test this "induced defe...