Field evaluation of selected botanicals and commercial synthetic insecticides against Thrips tabaci Lindeman (Thysanoptera: Thripidae) populations and predators in onion field plots

• Neem, Datura & Biter apple extracts showed good mortality of onion thrips.
• Botanicals had negligible impact on predators compared to synthetic insecticides.
• Acephate, spirotetramat and spinetoram provided excellent mortality of onion thrips.
• Weekly treatment of botanicals or insecticides against thrips is recommended.
• Botanicals or insecticides treated fields provided higher yields of onion.

The effectiveness of three botanical insecticides (neem, datura and bitter apple), and three new chemistry synthetic insecticides (acephate, spirotetramat and spinetoram) against onion thrips (Thrips tabaci) was evaluated in experimental field plots at university of Sargodha, Pakistan. The influence of these botanical and chemical insecticides on natural predators and crop yield was simultaneously investigated. All the botanicals and chemical insecticides tested caused significant reductions (45–70%) in thrips populations; the botanicals gave more than 60% control of thrips, while among chemical insecticides, acephate was found to be the most effective followed by spirotetramat and spinetoram, respectively, and these insecticides gave better control than the botanicals. The adverse effects of the botanicals on predator populations were negligible compared to the chemical insecticides. All chemical treatments resulted in a significantly higher yield compared to the untreated control. The botanicals and chemical insecticides became less effective by 7 days after treatment. Therefore, it is recommended that treatment with botanical or chemical insecticides should be repeated weekly consecutively at least three times to keep thrips populations below economic injury levels until crop maturity.