Technology.am (Nov 26, 2009) — When spider mites bother a bean plant, the plant responds by producing odors which draw rapacious mites. These predatory mites then eliminate the spider mite population, consequently performing as a sort of defender for the plant. Nevertheless, if the plant is concurrently attacked by whiteflies, insects that are associated to aphids, the plant becomes less eye-catching to the predatory mites and thus more susceptible to spider mites.
Jointly with German colleagues, researchers from the Laboratory of Entomology at Wageningen University, The Netherlands, published this breakthrough in the highly regarded journal Proceedings of the National Academy of Sciences.
The research team considered the strength of the plant’s “cry for help” throughout a chemical analysis of the plant odor blend and found that one of the odor components (beta-ocimene) is created in much lesser quantities if the plant is not simply attacked by spider mites, but in addition by whiteflies. The making of the odor decreases given that of a lesser expression rate of the plant gene that code for a vital enzyme in the production chain.
This latest advance demonstrates that there are in addition herbivores that can hinder with a plant’s “cry for help”, probably since the whiteflies try to interfere with the plant’s defense system. Spider mites too manufacture more offspring on a plant under attack by whiteflies. For a spider mite, there are thus two reasons why a bean plant which is being attacked by whiteflies is superior to a bean plant that is not being attacked: more offspring and fewer bodyguards. It is thus no surprise that the researchers found that the spider mite prefer plants infested with whiteflies above plants without them.
The outcome of this study is significant for integrated crop protection in which a mixture of methods can be used to battle different pests infesting a crop. Integrated crop protection offers efficient potential for environmentally safe pest control, and is based on solid information of the crop system and its multifaceted of enemies. Once it becomes understandable which insects weaken plant defense systems and which reinforce them, more alert research on environmentally-safe pest control will be likely, and people will no longer be caught off guard by unanticipated hindrance from some pest species.