Eugenol diffusion coefficient and its potential to control Sitophilus zeamais in rice

Abstract

Given the insecticidal potential of eugenol as a fumigant, this work aimed to determine the diffusion coefficient of eugenol emanating from a pure standard solution (99%), as well as from clove essential oil ( Eugenia caryophillata Thunb. (Myrtaceae)) through rice grain; to chemically analyse the volatile composition of commercially available eugenol and clove essential oil; and to evaluate the mortality of Sitophilus zeamais Motschulsky (Coleoptera: curculionidae) after exposure to eugenol inside a test chamber filled with rice. The solid phase microextraction method of extracting and quantifying eugenol by gas chromatography presented a good analytical response for the quantification of the analyte. There was no significant difference between the diffusion coefficient of eugenol diffusing from pure eugenol or from clove essential oil. The diffusion coefficient of eugenol through rice with the conditions herein adopted is 1.09 × 10 −3 cm 2 s −1 . The characterization of clove essential oil confirmed the presence of eugenol as its major component (74.25%). A difference was observed in the composition of the distinct phases evaluated. The exposure of adult S. zeamais to diffused eugenol from pure eugenol over seven days resulted in significantly higher mortality rates (~37%) than eugenol diffused from clove essential oil (~11%). No differences in mortality rates were observed in individuals placed at different positions inside the test chamber during eugenol fumigation.

Tradescantia pallida L. (Commelinaceae) influences the activity of oviposition and feeding of Plutella xylostella (Lepidoptera: Plutellidae)

“…Despite being efficient in most situations, synthetic insecticides can cause environmental and food contamination, in addition to contributing to biological imbalance due to the elimination of non-target organisms (Hernández & Vendramim, 1996;Valadares et al 2020). Therefore, the use of plant extracts, associated with other practices, is an option for integrated pest management as they are obtained from renewable sources (reflecting on the low financial cost) and effectiveness in low concentrations (Ware & Whitacre 2004;Koul et al 2008;Prates et al 2019) and in line with global interdisciplinary sustainability requirements (Cook et al, 2004). In this work, we emphasize the ovipotential and phagodeterrent action of T. pallida extract 10% under laboratory conditions, and we encourage future fieldwork to investigate the results under natural conditions.…”

Optimal Extraction of Ocimum basilicum Essential Oil by Association of Ultrasound and Hydrodistillation and Its Potential as a Biopesticide Against a Major Stored Grains Pest

“…The bioactivity of essential oils in pest management of stored grains is linked not only to their lethality, but also to behavioural changes aiming the increase in food safety and quality [ 33 , 36 , 37 , 38 ]. Together with other factors, like the diffusion of volatile components [ 39 , 40 ] and the persistence of components after application [ 41 ], the compositition of essential oils is important to predict its bioactivity.…”

The complete mitochondrial genome of the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae)

“…zeamais (Motschulsky, 1855) (Coleoptera: Curculionidae), which is a common pest of stored product and has a worldwide distribution, cause the greatest levels of damage to stored grain and threaten the food security (Ojo et al 2016). There have been many reports on biological characteristics, seasonal dynamics and biological control of the weevils (Haddi et al 2018;Prates et al 2019). However, genetic characteristics can be applied to phylogenetic analyses to estimate the evolutionary genomics based on comparisons of the mitochondrial genomes (Zhao et al 2018;Wang et al 2019).…”