Concepts in Insect-Pest Resistance

Abstract

Insects are usually specialized in their ability to attack their hosts or their parts. No insect is capable of attacking every species of hosts. Even the so-called polyphagous insect cannot feed on just any plant species. Even the oligophagous insects are restricted in their ability to utilize the varieties of one family of the host plant. Early literature contains several significant examples of differences in response to insect attack. The first mention of the possibility of resistance to the attack of hessian fly (Mayetiola destructor) was the Underhill variety of wheat in the year 1785. However, the first observations were published by Lindley (1831), Wickson (1886), Woodsworth (1891), and Kellner (1892). Snelling (1941b) reviewed the literature on this subject and observed that out of 567 references only 37 papers prior to 1920 dealt with plant resistance to insects. The publications in this field increased considerably after this period. According to him, plant resistance includes those characters which enable a plant to avoid, tolerate or recover from the attacks of insects under conditions that would cause greater injury to other plants of the same species.