Dispersal of aphids, whiteflies and their natural enemies under photoselective nets

Abstract

Integrated Pest Management of insects includes several control tactics, such as the use of photoselective nets, which may reduce the flight activity of insects. Limiting the dispersal of pests such as aphids and whiteflies is important because of their major role as vectors of plant viruses, while a minor impact on natural enemies is desired. In this study, we examined for the first time the dispersal ability of three vector species, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) and Myzus persicae (Sulzer) (Hemiptera: Aphididae), in cages covered with photoselective nets. Contrary to the results obtained with aphids, the ability of the whitefly B. tabaci, to reach the target plant was reduced by photoselective nets. In a second set of experiments, the impact of UV-absorbing nets on the visual cues of two important predator species, Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae), was evaluated. The anthocorid was caught in higher numbers in traps placed under regular nets, whereas the mites preferably chose environments in which the UV radiation was attenuated. We have observed a wide range of effects that impedes generalization, although photoselective nets have a positive effect on pest management of whiteflies and aphids under protected environments.

Management of Air-Borne Viruses by “Optical Barriers” in Protected Agriculture and Open-Field Crops

“…Results from experiments carried out in cages covered with UV-absorbing nets showed that visual cues in Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) may be disturbed under UV-absorbing covers, inducing a reduction in dispersal. UV-deficient environments formed under photoselective screens seem to be attractive for Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) (Legarrea, Weintraub, et al, 2012). It was suggested that the predatory mite attempts to avoid UV-B radiation that may reduce survival, egg laying, and hatching, as has been found for other predatory mite species (Onzo, Sabelis, & Hanna, 2010).…”

“…CYSDV incidence under the UV-absorbing films was 2% compared to 14% under an ordinary film (Mizrahi et al, 1998). Infection rates of the nonpersistent viruses Cucumber mosaic virus (CMV) and Lettuce mosaic virus were lower under UV-absorbing screens, probably due to the lower population density and dispersal rate of the aphid vector M. euphorbiae (Legarrea, Betancourtb, et al, 2012;Legarrea, Weintraub, Plaza, Viñuela, & Fereres, 2012).…”

Compatibilidad de Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) y Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae), importantes enemigos naturales de la mosca blanca Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) en cultivos hortícolas, con nuevas barreras físicas selectivas y modernos plaguicidas

“…A pesar de que existen estudios que afirman que el uso de barreras fotoselectivas es compatible con algunas especies de organismos de control biológico, como Orius laevigatus (Fieber) (Heteroptera: Anthocoridae), Aphidius colemani Viereck, Aphidius ervi Haliday, Aphidius matricariae (Haliday) (Hymenoptera: Braconidae), Diglyphus isaea Walker (Hymenoptera: Eulophidae) y E. formosa (Chyzik et al, 2003;Chiel et al, 2006;Doukas & Payne, 2007c;Legarrea et al, 2012aLegarrea et al, , 2014, éstas pueden tener un efecto negativo en algunas especies como E. mundus, al interferir con su orientación, lo que ocasiona una disminución de la depredación y la parasitación de los insectos plaga (Chiel et al, 2006).…”

“…Numerosos autores han puesto de manifiesto el excelente control de dichas barreras sobre distintas plagas tales como pulgones, moscas blancas, trips, ácaros y minadores de hojas, así como de los virus transmitidos por las mismas (Antignus et al, 1996(Antignus et al, , 1998(Antignus et al, , 2001Chyzik et al, 2003;Fereres et al, 2003;Kumar & Poehling, 2006;Doukas & Payne, 2007b;Legarrea et al, 2012aLegarrea et al, , 2012b.…”

“…Aunque la compatibilidad de las barreras fotoselectivas con agentes de biocontrol ha sido demostrada por diversos autores (Chyzik et al, 2003;Chiel et al, 2006;Doukas & Payne, 2007c;Legarrea et al, 2012aLegarrea et al, , 2014, éstas pueden interferir negativamente en la orientación de algunas especies de insectos útiles que basan su localización de presas principalmente en estímulos visuales, disminuyendo el control de plaga que estos insectos pueden llevar a cabo (Chiel et al, 2006;Legarrea et al, 2012a).…”