Ovicidal and Physiological Effects of Essential Oils Extracted from Six Medicinal Plants on the Elm Leaf Beetle, Xanthogaleruca luteola (Mull.)

Bita Valizadeh,Patcharin Krutmuang,Jalal Jalali Sendi,Marziyeh Oftadeh,Asgar Ebadollahi

doi:10.3390/agronomy11102015

Abstract

Plant essential oils may serve as safe alternatives to detrimental synthetic pesticides due to relatively lower side effects on the environment and non-targeted organisms. The current study was conducted to investigate the ovicidal toxicity and physiological disruptions of six medicinal plant essential oils, including Artemisia annua L., Lavandula angustifolia Mill., Origanum vulgare L., Rosmarinus officinalis Spenn., Satureja hortensis L., and Thymus vulgaris L., on elm leaf beetle Xanthogaleruca luteola (Mull.). The LC50 (Lethal Concentration to kill 50% of tested insects) values of 122.8, 287.5, 152.8, 180.6, 315.9, and 1366.2 ppm were recorded for T. vulgaris, L. angustifolia, A. annua, S. hortensis, R. officinalis, and O. vulgare, respectively, 72 h after treatment of 3-day-old eggs of the pest. Significant decreases in the amounts of glucose, protein, and triglyceride macromolecules were also observed after treatment. The application of essential oils derived from T. vulgaris, A. annua, and S. hortensis at 400 ppm revealed 100% ovicidal activity. Accordingly, tested essential oils, particularly the essential oil of T. vulgaris, have been promising potential as biorational insecticides in the management of X. luteola.

Highlights

The elm leaf beetle, Xanthogaleruca luteola Müller (Coleoptera: Chrysomelidae), is a defoliating pest of elm trees (Ulmus spp.) widely distributed in Europe, North Africa, Asia, Australia, and temperate areas in North and South America [1]
Since elm trees are widely planted in cities and suburbs, the excessive use of chemical pesticides to protect them from the population impact of X. luteola leads to municipal environment pollution, interruption of ecological balance, the mortality of non-target organisms, development of insecticide resistance, as well as toxic waste [3,4]
Some essential oils (EOs), such as thyme, should be applied at suitable times and with the concentrations recommended to reduce the inhibitory impacts on the hive

Summary

Introduction

The elm leaf beetle, Xanthogaleruca luteola Müller (Coleoptera: Chrysomelidae), is a defoliating pest of elm trees (Ulmus spp.) widely distributed in Europe, North Africa, Asia, Australia, and temperate areas in North and South America [1]. The eggs of elm leaf beetle are bright yellow and laid in clusters, averaging 14–20 eggs per cluster, that are mainly located on the underside of a leaf. Both larvae and adults of X. luteola feed on the emergent leaves. The larvae of the elm leaf beetle can feed on elm leaves for 2–4 weeks, undergo three instars, and cause more damage than adults by skeletonizing the leaf surface [2]. Severe infestations by elm leaf beetle larvae can cause physiological stress, defoliation of trees, and enhance the susceptibility of host plants to other pests and diseases [3]. Since elm trees are widely planted in cities and suburbs, the excessive use of chemical pesticides to protect them from the population impact of X. luteola leads to municipal environment pollution, interruption of ecological balance, the mortality of non-target organisms, development of insecticide resistance, as well as toxic waste [3,4]

Methods

Results

Conclusion