Alternative treatments in bean seeds for repelling Acanthoscelides obtectus (SAY)

Abstract

The objectives of this study were to evaluate treatments with alternative products for repelling bean weevils, and to assess their influence on the physiological quality of Phaseolus vulgaris seeds. The experiment was carried out in a completely randomized design, with four replications, in a two-factorial scheme (10x4). It comprised 10 treatments: Piper nigrum, diatomaceous earth and kaolin (4 g/kg of seed); Cinnamomum zeylanicum, Citrus sinensis and Eucalyptus sp. (1% of the seed weight); Azadirachta indica oil (3 mL/kg of seed); Gastoxin (6 g/t of seed); PET container; control; and the storage times of 0, 25, 50, and 75 days. The variables seed moisture content, germination, emergence speed, mean emergence time, weight of one thousand seeds, seed infestation, and repellency were evaluated. The treatments with kaolin and A. indica had a repellent effect at first, but they lost effectiveness by the end of the storage period. The products based on C. zeylanicum and Eucalyptus sp. did not have such impact during early periods of storage, albeit repellency grew with time. On the other hand, C. sinensis and diatom-based products were repellents, both at the beginning and at the end of storage. The treatments with diatomaceous earth, kaolin, P. nigrum, C. zeylanicum, Eucalyptus sp., A. indica, and PET container all proved to be effective in reducing bean weevil infestation, without negatively impacting the physiological quality of the seeds.

Toxic, Oviposition Deterrent and Oxidative Stress Effects of Thymus vulgaris Essential Oil against Acanthoscelides obtectus

“…Previous studies of EO effects in A. obtectus have involved EOs isolated from plants belonging to families of Amaranthaceae [58], Asteraceae [59], Cupressaceae [60], Lamiaceae [61][62][63], Lauraceae [64], Meliaceae [65], Myrtaceae [60,62,64,66], Piperaceae [65], Poaceae [67], Rutaceae [68]. In the present study we examined how thyme EO (Thymus vulgaris L., Lamiaceae, thymol chemotype) applied by contact affected A. obtectus mortality, F1 progeny production and choice of seeds for oviposition.…”

Ferulago campestris Essential Oil as Active Ingredient in Chitosan Seed-Coating: Chemical Analyses, Allelopathic Effects, and Protective Activity against the Common Bean Pest Acanthoscelides obtectus

“…Without any treatment, the A. obtectus populations grow exponentially and could completely destroy the stored beans [17]. The most common method to control weevil in beans for human consumption is by phosphine or pyrethroids [18]. As regards the seeds for sowing, the complete control of bruchids can be achieved by an insecticide coating of the stored seeds.…”

The effect of photoperiod on development time, sex ratio and fecundity of Acanthoscelides obtectus Say (Coleoptera: Bruchidae)

“…Recently, as a result of the increase in ecological awareness, biological control methods have begun to be used which can be an alternative to chemical control (Oliveira et al 2018). Success in biological control depends on the determination of control strategies and timing.…”