To lower mosquito exposure in malaria-prone places there are two basic pesticide use strategies. The half-century old approach - a remnant of 1950's era thinking - is to spray entire towns, as well as the surrounding countryside, with a pesticide such as DDT or pyrethrin.
Washingon DC-area Think tanks seem enamored of those spray-glory days, in spite of the fact that it would be a logistical impossibility and far too costly to repeat the Bald Eagle extirpating performance for the many thousands of poor communities in developing nations where malaria is a serious threat.
The contemporary strategy is targeted pesticide application, interrupting the exposure where it counts most - at home - and leaving the wildlife and farm animals alone. Pyrethrin-soaked bed nets have long been used to protect sleeping children; but, not everyone has a "bed" and the nets are too expensive for people on a subsistence income. Plus, just as happened with DDT, widespread spraying with pyrethrin has selected for resistant mosquitos.
Now, via SciDev.net comes news of promising results from field trials of carbamate-impregnated polypropylene, non-woven fabric or "sheeting" as it is being called.We're not talking Ralph Lauren wallpaper over drywall. The impregnated sheeting is hung against interior walls, where mosquitoes prefer to light. Paired with pyrethroid treated bet nets, the long observed trend toward pyrethroid resistance is overcome. From the original research report in Malaria Journal:
The experimental hut trial showed that the combination of carbamate-treated PPW and a pyrethroid-treated bed net was extremely effective in terms of mortality and inhibition of blood feeding of pyrethroid-resistant An. gambiae. This efficacy was found to be proportional to the total surface of the walls. This combination showed a moderate effect against wild populations of Cx. quinquefasciatus, which were strongly resistant to pyrethroid.
Targeting strategy highlights.
I'm writing this in Think Tank-ready bullet points. But, still anticipate being attacked for posting the facts.
- Mosquitos expose themselves to carbamate directly, when they land on fabric.
- Kids and pets not exposed.
- Fish, wildlife, and domestic animals not exposed.
- Minimum area covered so money not wasted.
- No spray equipment needed by homeowner.
- No pesticide spillage.
- Less likely to cause resistance in outdoor insects, which are left unexposed
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