# Prey-mediated effects of Mpp51Aa2-producing cotton on longevity and reproduction of Orius majusculus

## TL;DR

This study examines how Bt cotton producing Mpp51Aa2 affects the lifespan and reproduction of the beneficial predator Orius majusculus when fed different prey types.

## Contribution

The study reveals that prey type mediates the impact of Bt protein on non-target predators.

## Key findings

- Feeding on Bt cotton spider mites reduced the longevity and fecundity of O. majusculus.
- Feeding on Bt cotton larvae of S. littoralis had no adverse effects on predator longevity or reproduction.
- A diverse prey diet likely reduces Bt protein exposure to non-target predators in the field.

## Abstract

Genetically engineered (GE) cotton event MON 88702, producing Mpp51Aa2 (previously mCry51Aa2) from Bacillus thuringiensis (Bt), controls sucking pests, such as Lygus spp. (Hemiptera: Miridae) and thrips (Thysanoptera). Ingesting high doses of the insecticidal protein resulted in adverse effects on life table parameters of beneficial, predatory Orius spp. (Hemiptera: Anthocoridae). This triggered laboratory studies with more realistic food treatments, including different combinations of prey types with and without Bt protein to further characterize risks to this important group of non-target organisms. In this work, exclusive feeding of frozen spider mites (Tetranychus urticae, Acari: Tetranychidae) from Bt cotton confirmed adverse effects on longevity and fecundity of O. majusculus adults. Alternate feeding of Bt protein-containing spider mites and Bt-free Ephestia kuehniella (Lepidoptera: Pyralidae) eggs mitigated effects on longevity, but not on fecundity. When living larvae of Spodoptera littoralis (Lepidoptera: Noctuidae) from Bt cotton were fed to the predators, however, no effects on longevity and reproduction of female O. majusculus were observed, despite the fact that Bt protein concentrations in larvae were almost as high as concentrations in spider mites. When a diverse mix of prey species with various Bt protein concentrations is consumed in the field, it is unlikely that exposure of Orius spp. to Mpp51Aa2 is high enough to exert adverse effects on predator populations. MON 88702 cotton may thus be a valuable tool for integrated management of sucking pests.

The online version contains supplementary material available at 10.1007/s11248-024-00378-w.