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

10 páginas, 6 tablas y 2 figuras

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.

We would like to thank Rafi Mori for his technical assistance; Polysack Plastics Industries Ltd and Meteor Agricultural Nets Ltd for kindly providing the nets of study. We are indebted with Arnon Karnieli and Joaquín Campos for measuring the transmission properties of the nets. Besides, we would like to thank two anonymous reviewers and Patrick De Clercq (Handling Editor of BioControl) for their contribution to improve previous versions of the manuscript. Saioa Legarrea was financially supported by a scholarship I3PBPD-2006 and the work was funded by the Spanish Ministry of Science and Innovation (Research Grant, PET2006_0021; AGL2007-66399-C03-01/02).

Peer reviewed