Host selection chemical factors

The selection or avoidance of potential host plants by phytophagous Insects Is guided by a complex combination of physical and chemical stimuli. Color, shape and olfactory cues may play a role In the Initial orientation, whereas acceptance or rejection of a plant depends on texture as well as chemical stimulants or deterrents. Initiation of feeding Is stimulated or deterred by the presence or absence of specific chemicals or groups of chemicals, many of which have been Identified. The selection of a suitable plant for ovlposltlon Is also crucial for survival of the progeny of most herbivorous Insects, but the chemical factors Involved are known In relatively few cases. Ovlposltlon stimulants and deterrents often appear to be quite different from the chemicals that elicit or Inhibit feeding responses of larvae. 

The subject of host selection has been reviewed in depth by several authors (, ), and the chemical factors... 

The behavior of Insects In selecting a host plant for food and shelter is affected by a wide array of physical and chemical stimuli. Chemicals that play a role in resistance mechanisms may interfere with an Insect s orientation, inhibit feeding, or deter ovipositlon. Most of the known mechanisms of resistance involve feeding deterrents, but the most vulnerable phase of the Insect life cycle may prove to be ovipositlon. Environmental factors may influence the ability... 

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