How many Orius laevigatus are needed for effective western flower thrips, Frankliniella occidentalis, management in sweet pepper?

Frankliniella occidentalis (Pergande) is a primary pest of greenhouse crops worldwide, in organic and integrated pest management control practices, Orius spp. are frequently released for thrips control. However, Orius spp. are relatively expensive to produce. More cost-efficient rearing systems and reduced release rate might reduce the expense. In these trials, we released Orius laevigatus (Fieber) at different rates with or without simultaneous release the predatory mite Amblyseius swirskii Athias-Henriot, another known thrips predator, which is less expensive to rear. There was no significant difference in the number of O. laevigatus recovered in which either 2 or 6 individuals were released per square meter, and there was no difference in thrips control among any of the release strategies using O. laevigatus, suggesting that a reduced release rate can maintain effective thrips control. There was no significant difference in the quality or quantity of the pepper yield between treatments in which either 2 or 6 Orius/m2 or Orius plus A. swirskii were released.

► We compared two release rates of Orius, in the presence of A. swirskii, for the control of thrips.
► There was no significant difference in the number of Orius recovered between the two release rates.
► Thrips control and pepper yield and quality was equally good between the two release rates.
► We recommend a reduced release rate of Orius laevigatus.