Essential Oils from Six Herbal Plants for Biocontrol of the Maize Weevil

Abstract

<jats:p>Essential oils from sweet basil (<jats:italic>Ocimum basilicum</jats:italic> L.), holy basil (<jats:italic>O. americanum</jats:italic> L.), hairy basil (<jats:italic>O. tenuiflorum</jats:italic> L.), lime (<jats:italic>Citrus aurantifolia</jats:italic> Swingle), kaffir lime (<jats:italic>C. hystrix</jats:italic> DC.), and clove (<jats:italic>Eugenia caryophyllus</jats:italic> L.) were isolated by simultaneous distillation extraction. Toxicity assays against the maize weevil (<jats:italic>Sitophilus zeamais</jats:italic> Motschulsky) using 30 to 120 μL oil extract from the six plants on 70-mm-diameter filter paper discs resulted in 100% weevil mortality within the 5-h assay period. On rice samples, sweet basil oil extract was the most effective, resulting in 96% to 100% mortality regardless of oil extract volume on the first day during the 5-day assay period. Probit analysis showed that sweet basil oil extract applied on grains had four to five times lower LD<jats:sub>50</jats:sub> (lethal dose to kill 50% of the weevils) and two to three times lower LD<jats:sub>99</jats:sub> values than the remaining oil extracts. Repellency assay using 1 to 8 μL oil extract showed a different trend, because hairy basil was the most effective among treatments. Based on the effective control of the maize weevil by the oil extracted from herbal plants, such oil extracts could be useful in stored agricultural products and plant protection and reduce the risk associated with synthetic insecticides.</jats:p>

EVALUATION OF SOME PLANT EXTRACTS AGAINST MAIZE WEEVIL, Sitophilus zeamais (COLEOPTERA: CURCULIONIDAE) UNDER LABORATORY CONDITIONS

“…Mwangangi and Mutisya (2013) used O. basilicum extract against maize weevil and confirmed that O. basilicum extract has potential to control this pest effectively. Kerdchoechuen et al (2010) reported that sweet O. basilicum oil extract can caused 96 to 100% mortality of maize weevil, 5 days after application. It is concluded from current study, plant extracts have a potential to control maize weevil without causing lethal effects on stored commodity and environment and safer for health.…”

Volatile Compounds in Citrus Essential Oils: A Comprehensive Review

“…In fact, medium polarity solvents (diethyl ether, dichloromethane or ethyl acetate) extract more polar and higher MW compounds such as hexadecanal (Naef and Velluz, 2001; Gancel et al, 2002; Chisholm et al, 2003a,b; Cannon et al, 2015), squalene (Cheong et al, 2011b; Jiang et al, 2011), linoleic acid (Cheong et al, 2011b, 2012; Jiang et al, 2011), heptadecanoic acid (Delort and Jaquier, 2009; Jiang et al, 2011) or neophytadiene (Delort and Jaquier, 2009; Delort et al, 2015) than distillation or cold press extraction, and it fails to extract many monoterpene and sesquiterpene compounds which are characteristic of Citrus EOs (Jiang et al, 2011). Moreover, there are other minority extraction methods that use also organic solvents such as simultaneous distillation and extraction (SDE) (Akakabe et al, 2008; Kerdchoechuen et al, 2010; Sun et al, 2014a), microwave-assisted extraction (MAE) (Sun et al, 2014a; Liu et al, 2015), and ultrasonic-assisted extraction (UAE) (Alissandrakis et al, 2003; Darjazi, 2011b; Liu et al, 2012; Sun et al, 2014a; Zhang et al, 2017).…”

Toxicity of the essential oil of basil cultivars and hybrids and its repellent effect on stored grain pests

“…Some authors have reported the toxicity of O. basilicum essential oil on C. maculatus (KEITA et al, 2000;PASCUAL-VILLALOBOS et al, 2003;ALVES et al, 2015) and S. zeamais (MATTA et al, 2010). However, no study has analyzed the toxicity of the essential oils of the hybrids tested in this work against C. maculatus and S. zeamais.…”

“…The toxicity of basil essential oil has already been confirmed against Acanthoscelides obtectus (MAZZONETTO; VENDRAMIM, 2003), Callosobruchus maculatus (PASCUAL-VILLALOBOS et al, 2003), Rhyzopertha dominica (LÓPEZ et al, 2008), Sitophilus zeamais (ASAWALAM et al, 2008;MATTA et al, 2010), Tribolium castaneum (MISHRA et al, 2012), Zabrotes subfasciatus (FRANÇA et al, 2012), and Sitophilus oryzae (POPOVIĆ et al, 2006). However, no research has been carried out against C. maculatus and S. zeamais and the essential oil of basil hybrids using cultivars Sweet Dani, Maria Bonita, Genovese, and Cinnamom.…”