Insects plant selection

Arnold TM, TargettNM, Tanner CE, Hatch WI, Ferrari KE (2001) Evidence for methyl jasmonate-induced phlorotannin production in Fucus vesiculosus (Phaeophyceae). J Phycol 37 1026-1029 Bemays EA, Chapman RF (1994) Host-plant selection by phytophagous insects. Chapman Hall, New York... 

Bernays, E. A. and Chapman, R. F. 1994. Host-Plant Selection by Phytophagous Insects. London Chapman Hall. 

The characteristic taste or smell of a food is used to signal an acceptable or non-accept-able food source. The evolution of the senses capable of detecting NP has long predated humans. For example, it is clear that many insect species select their food source, or the food source for their offspring (i.e., which plant is chosen to lay eggs on), partly on the basis of the NP composition (see Chapter 9). 

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... 

Leaf odours. The total essence which emanates from growing leaves is not solely constituted of straight chain alcohols and aldehydes. In the insect s selection of a host plant, species-specific components might be involved. The leek moth Acrolepiopsis assectella is attracted by thiosulfinates, compounds isolated from leek. Cis-3-hexen-1-ol was also shown to be attractive (27). 

In a similar fashion, if a recombinant or mutation occurred in a population of insects that enabled individuals to feed on some previously protected group of plants, selection would carry that line into a new adaptive zone (4). Here the new group would be able to diversify with little competition from other phytophagous insects. All in all, the diversity of plants would tend to augment the diversity of Insects and the diversity of phytophagous insects would tend to enhance the diversity of plants. 

There are a number of possibilities for using plant secondary chemistry to control herbivory in crop plants. One possibility is to select for insect resistant lines and though it has been done in only a few cases, select for specific allomones. There are, however, some potential problems with this approach. There is a cost for the production of the secondary compounds which may be useful for defense ( ). Insect resistant soybean cultivars produce lower yields of seeds and accumulate nitrogen at a slower rate than insect susceptible varieties in the absence of herbivores 3 ). Conversely, varieties of crop plants selected for high yield are often more susceptible to insects, pathogens, and weeds (35). 

Nordlund, D. A., Lewis, L. C. and Altieri, M. A. (1988). Influences of plant-produced allelochemicals on the host/prey selection behavior of entomophagous insects. In Novel Aspects of Insect-Plant Interactions, eds. P. Barbosa and D. Letourneau, pp. 65-90. New York John Wiley Sons. 

Wood DL (1972) Selection and colonization of ponderosa pine by bark beetles. In Van Emden HE (ed) R. E. S. Symposium No. 6. insect/plant relationships. Blackwell, Oxford... 

Bioactive Volatile Compounds from Plants, A.C.S. Symp. 525, Washington, DC, 1993. (b) E.A. Bernays and J.A.A. Renwick, Host-Plant Selection by Phytophagous Insects, Chapman Hall, New York, 1994. 

Allelochemicals are most notable in examples of host-plant and nonhost-plant selection, a process that is vital for phytophagous pest insects to locate food plants and avoid unsuitable or toxic hosts. Aphids have taxonomi-cally unrelated summer and winter hosts. The bird-cherry-oat aphid, Rhopalosiphum yadi. is able to detect species-specific odors from each of its hosts, the bird-cherry tree. Prunus padus, in winter and summer cereal crops. One such allelochemical from the winter host is methyl... 

In contrast to the leaf surfaces much more is known about the chemistry of the leaf interior, which is probably considerably more complex. These compounds representing nutrients, toxic allelochemicals and allelochemicals with a host plant sign character, influence feeding behavior (see Scriber, Chapter 7). As can be seen from Table 1.1, contact chemoreceptors for all types of compounds have been identified in a variety of insect species. With the exception of the two beetle larvae and the locust, all of the examples are lepidopteran larvae mainly because the two pairs of sensilla styloconica on the galea (maxilla) of these larvae can be investigated easily (Schoonhoven and Dethier, 1966). The relatively small number of contact chemoreceptors (four sensilla with four neurons) and their importance for food plant discrimination (Hanson and Dethier, 1973) make them ideal for the study of contact chemoreception in relation to host plant selection. 

Thorsteinson, A. J. (1953) The chemotactic basis of host plant selection in an oligophagous insect (Plutella maculipennis (Curt.)). Can, J, ZooL, 31, 52-72. 

Williams, K. S. and Gilbert, L. E. (1981) Insects as selective agents on plant vegetative morphology egg mimicry reduces egg laying by butterflies. Science, 212, 467-9. 

Bemays EA, Chapman RF (1994) Host-plant selection by phytophagous insects. Chapman Hall, New York... 

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