This study assesses the feasibility of using natural enemies for the control of Acanthoscelides obtectus Say and Zabrotes subfasciatus Boheman (Coleoptera: Chrysomelidae), key pests of stored dried beans, Phaseolus vulgaris L. (Fabales: Fabaceae). The predatory mites Blattisocius tarsalis Berlese (Acari: Ascidae) and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) were able to prey on A. obtectus eggs, reducing the bruchid population by more than 60% under both controlled and warehouse conditions. Therefore, they show good potential as biological agents for controlling this pest. The larval parasitoids Anisopteromalus calandrae Howard and Lariophagus distinguendus Förster (Hymenoptera: Pteromalidae) were both moderately effective (34–38% reduction) at suppressing A. obtectus populations, but when A. calandrae was combined with B. tarsalis, a significant improvement in control efficacy (81% reduction in emergence) was observed. Therefore, the release of A. calandrae combined with B. tarsalis seems to be a promising strategy for controlling A. obtectus. Neither B. tarsalis nor A. swirskii were able to prey on Z. subfasciatus eggs. Only the parasitoid A. calandrae was moderately effective (39% reduction) at supressing Z. subfasciatus populations. Further testing is needed to identify other natural enemies that can complement the action of A. calandrae in reducing Z. subfasciatus populations.
Bibliographical noteFunding Information:
This research was funded by the Instituto Nacional de Investaciones Agrarias (INIA) of the Spanish Ministry of Economy and Competitiveness (grants RTA2014-00006-C02-01 and RTI2018-095526-R-100) and by the CERCA Program (Centres de Recerca de Catalunya, Spain) of the Generalitat de Catalunya. The first author is grateful to the Consejo Nacional de Ciencia y Tecnología (CONACYT México) for his scholarship. We thank the company AGROBIO S.L. for providing the predatory mites used in these experiments.
© 2020, International Organization for Biological Control (IOBC).
- Bruchid weevils
- Egg predators
- Larval parasitoids
- Stored products