Fumigant toxicity of volatile natural products from Korean spices and medicinal plants towards the rice weevil, Sitophilus oryzae (L)

Abstract

The fumigant toxicity of various volatile constituents of essential oils extracted from sixteen Korean spices and medicinal plants towards the rice weevil, Sitophilus oryzae L (Coleoptera: Curculionidae), was determined. The most potent toxicity was found in the essential oil from Mentha arvensis L. var piperascens (LC50 = 45.5 microliters litre-1 air). GC-MS analysis of essential oil from M arvensis showed it to be rich in menthol (63.2%), menthone (13.1%) and limonene (1.5%), followed in abundance by beta-pinene (0.7%), alpha-pinene (0.6%) and linalool (0.2%). Treatment of S oryzae with each of these terpenes showed menthone to be most active (LC50 = 12.7 microliters litre-1 air) followed by linalool (LC50 = 39.2 microliters litre-1 air) and alpha-pinene (LC50 = 54.9 microliters litre-1 air). Studies on inhibition of acetylcholinesterase activity of S oryzae showed menthone to have a nine-fold lower inhibitory effect than menthol, despite menthone being 8.1-fold more toxic than menthol to the rice weevil. Different modes of toxicity of these monoterpenes towards S oryzae are discussed.

Essential oils as biological alternatives to protect date palm (Phoenix dactylifera L.) against Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae)

“…has been previously reported by several authors (Lee et al, 2001a;Hori, 2003;Prajapati et al, 2005;Pavela, 2009) of monoterpenoids and sesquiterpenes (Kiran and Devi, 2007). The essential oils of T. capitatus, R. officinalis, and P. halepensis contains mainly monoterpenes such as carvacrol, 1,8-cineole, α-pinene, camphor, borneol, β-myrcene and sesquiterpenes such as (Z)-caryophyllene, which are known to possess insecticidal activity (Lee et al, 2001b;Rozman et al, 2007;Kordali et al, 2008;Silva et al, 2008;Lucia et al, 2009;Qin et al, 2010) (Table 1).…”

Phytochemicals from Ficus sycomorus L. leaves act as insecticides and acaricides

“…Toxicity in the fumigation bioassays most likely was attributed to penetrate the oil vapors in the respiratory (Ma´rio et al, 2012). The insecticidal varied with insect species, oil concentrations, exposure time and chemical composition of the oil, which in turn depends on the source, season and ecological conditions, method of extraction, time of extraction and plant part used (Lee et al, 2001). Akhtar and Isman (2004) showed that Zanthoxylum alatum was the most potent as a feeding deterrent and repellent, and also caused the highest mortality of Pieris brassiceae larvae.…”

Control of papaya fruits anthracnose by essential oil of Ricinus communis

“…Many studies have pointed out the possibility to use the plant essential oils in plant pathology for the control of pathogenic microorganisms (Smith et al 2000;Lo Cantore et al 2004). These essential oils contain a variety of chemicals, including terpenoids which are known to be involved in the plant defense mechanism against the plant enemies ( Lee et al 2001). For this reason, these compounds have been tested against several phytopathological agents.…”