Host-Plant Suitability

Abstract

The previous chapter has dealt with host plant finding and assessing. Here I will concentrate on the suitability of plants for the growth of phytophagous insects. The various plant characteristics, insect characteristics, and environmental factors influencing post-ingestive suitability for the growth of immature insects has been reviewed recently (Scriber and Slansky, 1981). The nutritional ecology of insects involves basic nutrition (requirements, concentrations and proportions; see Gordon, 1972), the dietetics (allelochemics, food consumption, behavior, and regulatory physiology; see Beck and Reese, 1976; Slansky and Scriber, 1984), and especially the ecological and evolutionary ramifications of these interactions (see Townsend and Calow, 1981; Slansky, 1982). Insect adaptations to plant chemical quality (i.e., spatial, temporal, or taxonomic differences) may be behavioral, physiological, or ecological. These adaptations include heritable and inducible detoxication mechanisms, homeostatic tradeoffs in rates and efficiencies, and must be interpreted in the light of the local plant resources available and the insect’s guild and life cycle. Feeding preferences and the degree of feeding specialization actually realized for an insect herbivore will be determined by its evolutionary history, its present ecological opportunities and restrictions, and its behavioral and physiological flexibility (Fox and Morrow, 1981; Scriber, 1983).