A terrific pest insect, the termite, has become the leading target for some interesting experimental researches. The termites every year gnaw away more than $1 billion in structural damage despite an ever growing array of insect control techniques. This kind of problems have press researchers to completely change their strategy in their struggle against these insects, because the neurotoxic chemicals, frequently used till now to control insects, can frequently harm other similar organism because of, the nervous systems are frequently at least a little bit alike. For this reason 'the trend in insect control is to find methods that eliminate the problematic insect without affecting anything else in the environment,' said Michael Scharf, an entomologist with the University of Florida’s Institute of Food and Agricultural Sciences. 'What could possibly be more specific than genes that are unique to the insect itself?' So the termite genome is now the target of the most recent studies.
In a paper published online this week in the journal 'Insect Biochemistry and Molecular Biology', Scharf, along with colleagues Xuguo Zhou, Faith Oi and graduate student Marsha Wheeler, describes the effects of a mixture that, when consumed by termites, causes them to be deformed after molting. This mixture acts on a specific gene of termite genome and this fact make this new strategy the most effective and environmentally friendly.
The active agent in this 'genetic pesticide' is a small strip of RNA , since certain lower life organisms seem to be able to absorb RNA by simply consuming it. The RNA easily absorbed interacts with messenger-RNA (m-RNA) in the termite genome, preventing it to transcript the genetic message of a targetted portion of the DNA code. RNA interference techniques are commonly used to discover what a gene does into an organism by 'silencing' it and seeing what happens. In this way we can kill a little insect without any risk not only for humans but also for mice.
Despite certain pests’ susceptibility to RNA interference, any marketable genetic pesticide is still many years away from development, Scharf said.
Anyway when and if these new generation of agrochemicals will be into use they may solve the major problem of modern insecticides: they can prevent the development of insect resistance to toxins that, in other case, can frequently occur using those agrochemicals affecting insect nervous system. Besides it may be too much expensive go on rotating continuously between crop pesticides. When pests grow resistance and farmers don't rotate these products, they sometimes compensate by using more of the toxins, which can pollute groundwater and contaminate the surrounding areas.
The type of changes required to adapt the insects to genetic pesticides would be much more difficult for farm pests to overcome. And even if they did, there are thousands of genes within an insect’s genome that could be similarly targeted.
Further interest in the research to sequence the termite entire genome we can find in the U.S. Department of Energy. They hope it will be shed light on biological processes that could help researchers find ways to break down woody cellulosic materials into alternative fuels such as ethanol.
Source: University of Florida’s Institute of Food and Agricultural Sciences, May 28, 2008
Author: Luca Federico Fianchini, Jun 30, 2008