Synergistic Toxicity Interactions between Plant Essential Oil Components against the Common Bed Bug (Cimex lectularius L.)

Abstract

Management of the common bed bug (Cimex lectularius L.) necessitates the use of multiple control techniques. In addition to synthetic pesticides and mechanical interventions, plant-derived essential oils represent one of the control options. Mixtures of two or more essential oil components (monoterpenoids) exhibit synergistic toxicity effects against insects due to increased cuticular penetration. Monoterpenoids, such as carvacrol, eugenol and thymol, are neurologically active and inhibit the nerve firing activity of C. lectularius. However, the effects of mixtures of these monoterpenoids on their toxicity and neuroinhibitory potential against C. lectularius are not known. In this study, the toxicity levels of a tertiary mixture of carvacrol, eugenol and thymol (1:1:1 ratio) and a binary mixture of synthetic insecticides, bifenthrin and imidacloprid (1:1 ratio) were evaluated against C. lectularius through topical bioassays and electrophysiology experiments. Both a mixture of monoterpenoids and the mixture of synthetic insecticides exhibited synergistic effects in topical bioassays. In electrophysiology experiments, the monoterpenoid mixture led to greater neuroinhibitory effects, whereas a mixture of synthetic insecticides caused higher neuroexcitatory effects in comparison to single compounds. This study shows evidence for neurological mechanisms of synergistic interactions between monoterpenoids and provides information regarding the utilization of natural compound mixtures for C. lectularius management.

Potential of Essential Oils from Anise, Dill and Fennel Seeds for the Gypsy Moth Control

“…Studies on the structure-function relationship of EO constituents point out that molecular shape, degree of saturation, volatility and type of functional groups contribute to the efficacy of natural insecticides [ 102 ]. Besides, it has been well documented that EO compounds act in synergy and affect multiple targets in pest insects [ 93 , 94 , 103 , 104 , 105 ].…”

Behavioral and Antennal Responses of Tribolium confusum to Varronia globosa Essential Oil and Its Main Constituents: Perspective for Their Use as Repellent

“…The main chemical classes of volatile organic compounds present in plant essential oils are terpenes, phenol-derived aromatic components and aliphatic components, and their bioactivity is frequently a result of synergy among constituents [ 12 ]. Recently, synergistic effects of essential oil compounds or mixtures of essential oils have been demonstrated for various types of bioactivity, including antioxidant, antimicrobial, and insecticide effects [ 13 , 14 , 15 ].…”

Effects of Chemical Insecticide Residues and Household Surface Type on a Beauveria bassiana-Based Biopesticide (Aprehend®) for Bed Bug Management

“…The only exception to this may be prior use of EcoRaider, which did impact both viability and efficacy of Aprehend even when the residues were three weeks old. This is unfortunate, since recent research into essential oils for bed bug control has demonstrated their potential utility as alternatives to conventional chemicals for bed bug control and resistance management [ 6 , 8 ]. Unlike their observed synergistic effect with chemical insecticides [ 30 ], essential oils appear to have a detrimental impact on B. bassiana spores.…”

“…Biopesticide products are of growing interest [ 4 ]. Botanical and non-chemical control methods such as the use of natural compound mixtures [ 6 , 7 , 8 ], microbial control using Serratia marcescens , Pseudomonas fluorescens , and Bacillus thuringiensis israelensis [ 9 ] and the use of entomopathogenic fungi like Metarhizium anisopliae [ 10 , 11 ] and Beauveria bassiana [ 12 , 13 , 14 , 15 ] are being investigated.…”