Insecticidal Activity of Compounds of Plant Origin on Mahanarva spectabilis (Hemiptera: Cercopidae)

Abstract

The damage caused by spittlebugs varies according to the species of grass, and the losses can reach alarming levels. Measures for population control are currently restricted to the use of resistant grasses and the diversification of pastures. Therefore, alternative control measures are necessary, such as the use of botanical insecticides. The aim of this study was to evaluate the insecticidal activities of thymol, carvacrol, eugenol, cinnamaldehyde, and trans-anethole on Mahanarva spectabilis eggs, nymphs, and adults under laboratory conditions. In the egg tests, treatments with eugenol, carvacrol, and thymol showed the highest mortalities, presenting efficiencies higher than 85% after 48 h of application. In the nymph tests, the treatments with thymol and carvacrol at 2.5% and eugenol at 2.0% and 2.5% showed intermediate efficiencies, with values above 61%. The highest mortality was observed in the treatment with trans-anethole at 2.5%, with an efficiency of 95%. In the tests with adults, only treatment with trans-anethole at 2.5% obtained an efficiency reaching 90%; in the other treatments, the efficiency did not exceed 51%. These results showed that, at these concentrations, trans-anethole presents a high rate of insecticidal activity on M. spectabilis nymphs and adults and, therefore, is recommended as a potential natural insecticide for the control of this pest.

Susceptibility of Four Species of Aphids in Wheat to Seven Insecticides and Its Relationship to Detoxifying Enzymes

“…Imidacloprid, the first commercialized insecticide of this class with high effectiveness against several sucking pests ( Tomizawa and Casida, 2003 ; Lu et al, 2016 ), and it has been used as a seed treatment for controlling grain aphids in recent years ( Miao et al, 2014 ). However, concerning the environmental impacts and resistance, the application of botanical insecticides such as abamectin, matrine and rotenone has been augmented ( Dias et al, 2019 ; Jesser et al, 2020 ). New types of insecticides provide more choices for pest management, but the effectiveness needs further studies.…”

Biofoam of Spittlebug, Poophilus costalis (Walker): Preferential Sites, Temperature Regulation, Chemical Composition and Antimicrobial Activity

“…Several methods including the use of synthetic chemical insecticides and biopesticides have been used to control this pest [ 6 ]. However, the foaming substance produced by the spittlebug nymphs, which protects them against predators and parasitoids and acts as thermal insulation [ 9 ], is an important obstacle in their management [ 10 ]. Indeed, the chemical composition of and beneficial organisms contained in the foam produced by spittlebugs protect the nymphs [ 11 , 12 ].…”

Allelopathic, Phytotoxic, and Insecticidal Effects of Thymus proximus Serg. Essential Oil and Its Major Constituents

“…Park et al ( 2017 ) measured the insecticidal activity of thymol, carvacrol, citral, 2-isopropylphenol, 3-isopropylphenol, and 4-isopropylphenol against Pochazia shantungensis adults, and their LC 50 values were 28.52, 56.74, 89.12, 71.41, 82.49, and 111.28 mg/L, respectively. Dias et al ( 2019 ) evaluated the toxicity of thymol, cinnamaldehyde, carvacrol, eugenol, and trans-anethole on Mahanarva spectabilis eggs, nymphs, and adults, and they found that treatments with eugenol, carvacrol, and thymol showed the highest mortalities, presenting efficiencies higher than 85% after 48 h of application. Traboulsi et al ( 2002 ) found that the compounds thymol, carvacrol, (1R)-(+)-α-pinene, and (1S)-(–)-α-pinene showed potent toxicity (LC 50 36–49 mg/L), whereas menthone, 1,8-cineole, linalool, and terpineol (LC 50 156–194 mg/L) were less toxic to the mosquito Culex pipiens molestus.…”