Acylsugar tomato lines suppress whiteflies and Amblyseius swirskii establishment

Abstract

AbstractPlant defense traits such as trichomes along with biocontrol agents may provide alternatives to insecticide use in tomatoes, Solanum lycopersicum L. (Solanaceae). However, plant‐herbivore‐natural enemy interactions are not always complementary. In a series of greenhouse and field experiments, we explored whether augmented defense traits (i.e., production of acylsugars) in tomato plants could reduce sweet potato whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), populations and aid the establishment of the predatory mite Amblyseius swirskii Athias‐Henriot (Acari: Phytoseiidae). In the field experiment, commercial tomato cultivars and acylsugar‐producing tomato lines received no predatory mites or mites released via three methods: dusting on top, dusting on bottom, or slow‐release sachets. In the first greenhouse experiment, predatory mites were released onto the commercial and acylsugar‐producing tomato plants via sachets. In the second greenhouse experiment using a similar design, we augmented the mite diet with an alternative non‐prey resource (i.e., cattail pollen). Our results indicated that acylsugar‐producing tomato plants supported significantly fewer whiteflies than the commercial lines in all experiments. However, in the field, despite lower whitefly numbers, Tomato yellow leaf curl virus (TYLCV) (Geminiviridae, Begomovirus) was detected at higher frequencies in acylsugar‐producing lines. Few mites were recovered from all commercial and acylsugar‐producing lines in the field or greenhouse experiments suggesting A. swirskii does not establish well on tomatoes, and acylsugar lines successfully decreased whitefly populations but not a viral disease transmitted even at low whitefly abundance.