Biological activity of essential oils from seven Azorean plants against Pseudaletia unipuncta (Lepidoptera: Noctuidae)

Abstract

Ten essential oils from seven Azorean plant species were evaluated for their insecticidal, ovicidal, feeding‐deterrence and growth inhibition activities against Pseudaletia unipuncta. The oils of Laurus azorica (leaves), and Juniperus brevifolia (leaves) showed strong moderate insecticidal effect on fourth‐instar larvae causing 93.3% and 46.7% mortality, respectively. Juniperus brevifolia (leaves), L. azorica (leaves), Persea indica (leaves), Hedychium gardnerianum (leaves) and Pittosporum undulatum (fruits and leaves) significantly affected the hatching of P. unipuncta eggs (<8% eclosions). Five oils showed significant feeding deterrent activities (L. azorica, 92.4%, J. brevifolia, 93.6%, P. undulatum leaves, 95.5% and fruits, 83.8% and H. gardnerianum, 88.2%). All of the essential oils tested, significantly inhibited the larval growth after 5 days of feeding on the treated diet. Essential oils from L. azorica and J. brevifolia were the most potent growth inhibitors among the oils tested, producing a decrease in the initial larva weight (−14.8 and −14.5 mg, respectively). Our results indicate that L. azorica (leaves), J. brevifolia (leaves), P. indica (leaves), H. gardnerianum (leaves), and P. undulatum (leaves and fruits) can be exploited for the development of bioactive compounds as a new source of agrochemicals. Further emphasis on isolation and identification of active constituents can be useful to develop new environment‐friendly insect control agents.

Chemical Composition and Larvicidal Activities of the Himalayan Cedar,Cedrus deodaraEssential Oil and Its Fractions Against the Diamondback Moth,Plutella xylostella

“…In another study, essential oils of Thymus vulgaris (LC 50 = 4.8 mg/ml), Syzygium aromaticum (LC 50 = 6.0 mg/ml), Cymbopogon citrates (LC 50 = 7.7 mg/ml), Cinnamomum cassia (LC 50 = 8.5 mg/ml), Cymbopogon nardus (LC 50 = 10.1 mg/ml) were found toxic to T. ni larvae in residual bioassays ( Jiang et al 2010 ). Laurus azorica and Juniperus brevifolia leaf essential oil caused 93.3% and 46.7% mortality of fourth-instar larvae of the armyworm, Pseudaletia unipuncta , and all essential oils significantly inhibited larval growth after five days of feeding on the treatment diet ( Rosa et al 2010 ).…”

Contact and Repellent Activities of the Essential Oil from Juniperus formosana against Two Stored Product Insects

“…oryzae [20,21], T . castaneum [21,22], Pseudaletia unipuncta [23], Xenopsylla cheopis [24], Resseliella oculiperda [25], Reticulitermes speratus [26] and Acanthoscelides obtectus [27]. However, there is no reporting on the insecticidal or repellent activity of the essential oil from J. formosana against T. castaneum and L. bostrychophila .…”

Activities of Apiaceae essential oils and volatile compounds on hatchability, development, reproduction and nutrition of Pseudaletia unipuncta (Lepidoptera: Noctuidae)

“…Mythimna) unipuncta, Haworth 1809 (Lepidoptera: Noctuidae), also known as the true armyworm, is a seasonal and migrant noctuid which cause considerable plant damage in small grain crops (namely barley, oats, rice, rye and wheat), sugarcane, maize and forage grasses (Silva et al, 2003). A variety of extracts and allelochemicals from several botanical origins have been previously tested for their antifeedant and crop protection potential against P. unipuncta and other important phytophagous insects (Akhtar and Isman, 2004;Akhtar et al, 2008;Isman et al, 2008;Rosa et al, 2010). In general, the evaluation of plants extracts activities against many lepidopterous insects are centered on acute toxicity tests or feeding-deterrence assays, for estimation of the respective lethal and deterrent doses.…”