Violet LED light enhances the recruitment of a thrip predator in open fields.
The predatory bug Orius sauteri is an indigenous natural enemy of thrips and whiteflies in Asian countries. To put these bugs to practical use in pest management, methods to attract and retain the bugs in agricultural fields are needed. We previously showed that violet light (405 nm) attracts O. sauteri selectively. Many thrips and whiteflies are attracted to UV or green light. In this study, we examined the effect of violet-LED illumination on O. sauteri in pesticide-free eggplant (Solanum melongena L.) cultivation. In three cultivation trials, the density of O. sauteri on eggplant leaves was consistently higher in the illuminated plots; at least twice that of the non-illuminated plots. Simultaneously, the density of thrips declined markedly to less than half that of the non-illuminated plots. We identified three positive effects of violet light including an "immediate-effect" on predator attraction, a "persistent-effect" on predator reproduction, and a "secondary-effect" on the food web structure. Our results showed that illumination with violet light provides a powerful tool for integrated pest management. This is the first report on the use of illumination to manipulate the behavior of natural enemies.
Institute of Agrobiological Sciences, NARO; Ohwashi 1-2, Tsukuba, Ibaraki 305-8634, Japan.|Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Takumi
T
Ogino
Institute of Agrobiological Sciences, NARO; Ohwashi 1-2, Tsukuba, Ibaraki 305-8634, Japan.
Takuya
T
Uehara
Institute of Agrobiological Sciences, NARO; Ohwashi 1-2, Tsukuba, Ibaraki 305-8634, Japan.
Masahiko
M
Muraji
Institute of Agrobiological Sciences, NARO; Ohwashi 1-2, Tsukuba, Ibaraki 305-8634, Japan.
Terumi
T
Yamaguchi
SHIGRAY Inc., Sumida, Tokyo, Japan.
Takahisa
T
Ichihashi
SHIGRAY Inc., Sumida, Tokyo, Japan.
Takahiro
T
Suzuki
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Yooichi
Y
Kainoh
Institute of Agrobiological Sciences, NARO; Ohwashi 1-2, Tsukuba, Ibaraki 305-8634, Japan.
Masami
M
Shimoda
D000818:Animals; D005247:Feeding Behavior / Q000528:radiation effects; D020387:Food Chain; D020062:Heteroptera / Q000502:physiology; D006790:Host-Parasite Interactions / Q000528:radiation effects; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D010572:Pest Control, Biological / Q000379:methods; D018515:Plant Leaves / Q000469:parasitology; D011157:Population Dynamics; D011235:Predatory Behavior / Q000528:radiation effects*; D012666:Semiconductors; D032323:Solanum melongena / Q000469:parasitology; D061149:Thysanoptera / Q000502:physiology*