Biological Control of Echinothrips americanus Morgan (Thysanoptera: Thripidae) in Sweet Pepper Using the Predatory Thrips Franklinothrips vespiformis Crawford (Thysanoptera: Aeolothripidae)

Echinothrips americanus Morgan (Thysanoptera: Thripidae), also known as poinsettia thrips, has invaded several parts of the world becoming an important pest in many vegetable and ornamental crops. While biological control methods using predatory mites and bugs have been effective against flower-dwelling thrips, they have shown limited success against leaf-dwelling thrips like E. americanus. Franklinothrips vespiformis Crawford (Thysanoptera: Aeolothripidae) is a leaf-dwelling predatory thrips that may offer a more effective solution due to its overlapping habitat with E. americanus which increases the likelihood of predator–prey interactions. This study aimed to evaluate the potential of F. vespiformis for controlling E. americanus populations in sweet pepper under greenhouse conditions. We also investigated whether supplementing the releases of the predator with Artemia franciscana Kellogg (Branchiopoda: Artemiidae) cysts would enhance the pest control efficacy of F. vespiformis. Our results showed a 93% decrease in the total E. americanus population with releases of F. vespiformis alone and a 98% decrease when the releases of F. vespiformis were supplemented with A. franciscana cysts, both of which were statistically significant compared to the control treatment. There was no significant difference between the two F. vespiformis treatments. Similarly, the abundance of both adults and immature stages of E. americanus was significantly reduced in the presence of F. vespiformis, regardless of the addition of supplementary food. Overall, these findings highlight the potential of F. vespiformis for the biological control of E. americanus and probably other leaf-dwelling thrip pests in sweet pepper.