Host-Plant Suitability

Feeny (1976) and Rhoades and Cates (1976) proposed the concept of plant apparency to explain the complex mechanisms which govern insect-plant interactions (see also Gilbert, 1979). Although the ecological and evolutionary suitability of a plant will depend upon its apparency to insect herbivores, the 

Chemical Ecology of Insects. Edited by William J. Bell and Ring T. Card6 1984 Chapman and Hall Ltd. 

The objective of this chapter is to describe larval digestive efficiency and growth performance of phytophagous insects in relation to the chemical composition of their foodplants, and to discuss various insect adaptations (primarily behavioral and biochemical) which may improve the suitability of plant tissues for larval survival and growth. A physiological efficiency model is presented in relation to ecological and evolutionary interpretations of insect-plant interactions, with particular emphasis on a feeding specialization hypothesis. 

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The host plants suitable for Armenian cochineal grow only in Armenia and Azerbaijan, particularly on the soil of flat valleys, e.g. along the banks of the Araxes river up to the north and east of Mount Ararat (10). 

Host plant suitability involves various plant characteristics and insect herbivore adaptations as well as modification of both the plant and the insect by abiotic and biotic factors in their commimity. The post-ingestive growth performance of Lepidoptera (and perhaps most other leaf-chewing insects as well) is determined to a large extent by plant chemical quality (i.e., nutrients and allelo-chemics) and can be indexed by leaf water-nitrogen composition. 

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