Life cycle and host-dependent rearing efficiency of Thrips tabaci on onion and runner bean

Onions are the second most widely produced vegetable globally, after tomatoes and are vulnerable to both biotic and abiotic stresses. Among the key pests, Thrips tabaci is a polyphagous species that poses a major threat to onion production, causing direct damage and acting as a vector for tospoviruses. This study used ITS2-based PCR and Sanger sequencing to molecularly confirm the identity of field-collected T. tabaci, showing 100 % identity with reference T. tabaci sequences. The life cycle of T. tabaci was evaluated under controlled conditions on onion (Allium cepa) and runner bean (Phaseolus coccineus). Developmental parameters including egg, nymphal, pupal stages and adult longevity, were recorded on both hosts. Development was significantly faster on runner bean leaves (29.33 ± 5.58 days), while adult longevity was greater on onion leaves (20.07 ± 5.10 days). Mass rearing trials on single-host systems showed that onion leaves supported a higher multiplication fold (4.34 ± 0.63) compared with bean leaves (2.75 ± 0.50) when 100 adults were released. This indicates that the onion is more suitable for oviposition and overall colony buildup than the runner bean under controlled conditions. These findings show how the life cycle of T. tabaci can be regulated by its host. Collectively, onion favoured oviposition and overall colony build-up, while runner bean accelerated immature development-complementary traits that can be leveraged for laboratory culture and bioassay logistics.