On ecological fitting, plant–insect associations, herbivore host shifts, and host plant selection

"Pests soon colonize plants that are cultivated extensively, plant species recruit different pest species in different regions, and associations of insects with plants are often more casual, fortuitous, and labile than those usually interpreted as coevolutionary." ( Strong 1979 , pp. 89)

"…  when a parasite arrives in a new habitat, it will feed on those species whose defense traits it can circumvent because of the abilities it carries at the time. Such a parasite cannot be distinguished from one that evolved the ability to circumvent a defense while in trophic contact with its host." ( Janzen 1980 , pp. 611)

"We believe that a reasonable null hypothesis  …  is that many associations between insects and plants can occur without much evolution…" (Rey, McCoy and Strong 1981, pp. 620)

"The main role of secondary plant substances in insect/host plant relationships is that they form the 'fingerprint'  …  by which the insect recognizes the plants  …  The recognition of a plant as host is unrelated to whether the plant and the insect have evolved together or whether they meet for the first time in their evolutionary history." ( Jermy 1984 , pp. 620)