Adaptive Divergence of Chewing and Sucking Arthropods to Plant Allelochemicals

The possible differences in metabolic mechanisms within chewing and sucking arthropods in response to their phytochemical niches are discussed and, expectedly, contrast in their capabilities for eluding plant defenses are discussed.

Abstract

Plant-feeding arthropods, in the course of evolutionary time, have adapted differentially to plant hosts and thereby achieved optimized use of available resources. Divergent patterns of niche orientation have lead to guilds of herbivores that may specialize on a single common plant host. Plants, in turn, have responded by developing chemical and morphological defenses to discourage potential consumers, particularly where a low apparency (sensu Feeny, 1976) is not sufficient to assure the plant's survival. These arthropod-plant coadaptations have resulted in herbivores that represent very distinct feeding modes, and, expectedly, contrast in their capabilities for eluding plant defenses. Leaf-chewing lepidopterans, coleopterans, and orthopterans should have very different exposures to plant allomones compared to phloem-sucking homopterans and hemipterans. The possible differences in metabolic mechanisms within chewing and sucking arthropods in response to their phytochemical niches are discussed in this review.