San Francisco – spiders have rarely been taken into account in the search for bioinsecticides. An error now shows how: In the venom of a tarantula Australian researchers have tracked a highly effective insecticide. The peptide-1 Cast OAIP better than many synthetic insecticides against cotton capsule owls, the scientists report in the journal “PLoS One”. The moth in southern countries mitigate the cotton and corn harvest. OAIP-1 was discovered in the venom of the tarantula Selenotypus plumipes, one with 16 cm leg span of the largest arachnids Australia.
spiders are the biggest natural resource for acting against insect toxins, the team writes to Glenn King and Maggie Hardy of the University of Queensland (St. Lucia / Australia). However, these spiders would usually inject into their prey – there is therefore no selection pressure for a toxic effect when taken orally. However, insecticides are usually so common that they are eaten by pests.
Assuming the spider poisons had no effect anyway, if they only eaten by insects and these are not injected, was not even tested their effectiveness, the researchers explain. Now analyzed the toxic cocktail of tarantula on what substances also affect the oral route against plant pests.Many pests resistant to conventional agents
OAIP-1 in the diet therefore died not only cotton capsule owls, but also termites (Coptotermes acinaciformis) and mealworms (Tenebrio molitor). At the molecular level, the peptide resembles the so-called pyrethroids, synthetic insecticides that act rapidly and in low doses. It can be produced synthetically in the laboratory and was testing at temperatures up to 30 degrees for a week at least remained stable, according to the study. Feasible to use in combination preparations or in transgenic plants is.
insects reduce annual crop yields around the world ten to 14 percent, the researchers write. When storing an additional nine to 20 percent were lost due to pests. Although there are now new methods such as the use of transgenic plants, but synthetic insecticides dominated on. Most substances but to put on a few points in the insect metabolism. More than 500 species of arthropods – including the major pests – were therefore become resistant to one or more insecticide classes
In the past ten years have therefore been increasing interest in bioinsecticides derived from microbes, insects or even spiders. They often worked specifically on individual species, the production costs are comparatively low and it offers the opportunity to infiltrate the underlying genetic information in plants. As an example, the soil bacterium called Bacillus thuringiensis, Bt toxins which are used for pest control in agriculture and forestry – and against mosquitoes
track of the news
Help Get hold of free news services:
- everything from the category Science
- Twitter | RSS
- everything from the category Nature
- everything about agriculture