Smallanthus sonchifolius as a trap plant for Bemisia tabaci: host preference, host suitability, and semi-field...

This study aimed to identify promising trap plants for Bemisia tabaci among five host plants by integrating laboratory host preference and host suitability with semi-field population suppression under protected tomato cultivation.

Laboratory assays assessed adult settling and oviposition preference and the survival and development of B. tabaci on the five plants. A greenhouse trial then evaluated whether planting these plants around protected tomato reduced B. tabaci densities on the main crop.

55.33% of female and 54.17% of male B. tabaci adults chose Smallanthus sonchifolius, whereas less than 10% of adults chose Phaseolus vulgaris and Nicotiana tabacum. The number of eggs laid by B. tabaci adults on S. sonchifolius reached 260.30 per plant, which was significantly higher than those on other plants. Considering the entire stage from egg to adult, the survival rate of B. tabaci on S. sonchifolius was highest (53.33%); and lowest on N. tabacum (23.83%). The development time of B. tabaci egg to nymph was longest on N. tabacum (33.45 days), and shortest on S. sonchifolius (21.78 days). The lifespan of adults was longest on S. sonchifolius (24.03 days), and shorter on N. tabacum (15.33 days). In a semi-field greenhouse trial, planting S. sonchifolius as a trap plant significantly reduced B. tabaci population on tomato plants under protected cultivation, with adult densities below 400 individuals per 100 cm² leaf and nymph densities below 550 individuals per 100 cm² leaf.

In summary, B. tabaci showed a strong settling and oviposition preference for S. sonchifolius, and this plant may have potential as an attractive trap plant for ecological management of B. tabaci, provided that B. tabaci on the trap plants is controlled promptly to prevent the plants from becoming a population source.