ECOLOGICAL BIOCHEMISTRY - Study Guide - V. M. Isaenko 2005

Chapter 6. ECOLOGICAL AND BIOCHEMICAL INTERACTIONS AMONG ANIMALS

6.3. Interactions between animals of different species

6.3.3. Kairomones

As previously noted, kairomones are substances that are perceived by recipient organisms as beneficial. In predator-prey interactions, kairomones are substances produced by prey animals that benefit the predators. At the same time, predator-derived substances can warn a potential prey of a predator's presence, thereby allowing the prey to avoid it.

According to their mode of action, kairomones can be classified into: 1) feeding attractants; 2) adaptation stimulators; 3) chemosignals that warn the recipient of danger from the Organism emitting these signals; and 4) growth factor stimulators.

One manifestation of kairomone interaction can be observed in the relationship between larvae of the corn earworm Heliothis zea and females of Microplitis croceipes, a parasitoid species targeting H. zea larvae. It has been shown that tannin compounds present in the cuticle of Heliothis zea larvae stimulate the reproductive activity of Microplitis croceipes females. 13-methylhentriacontane has been identified as one of the potential active components. Furthermore, volatile chemicals emitted by female Heliothis zea have been found to increase the oviposition rate of this lepidopteran.

Another example is the bark beetle sex pheromone brevicomin, which is utilized by the predatory beetle Thanasimus dubius to locate its prey. It appears that the pheromones of certain insects can occasionally function simultaneously as kairomones for their predators and parasites.

Kairomones can also be employed by potential prey to detect predators. For instance, chemical substances released by predatory starfish trigger escape responses in a range of marine organisms, such as Dendraster excentricus, Pecten, and Nassa.

There are numerous other Examples of kairomone action in invertebrates and vertebrates. Some of these are summarized in Table 6.4.

Class="center">Table 6.4

SOME ANIMAL KAIROMONES (after Telytchenko and Ostroumov, modified)

In aquatic organisms (such as crustaceans, gastropods, etc.) acting as potential prey, predator exometabolite-kairomones can induce The Development of morphological defensive structures and other inducible defense mechanisms (such as spine formation).