title: Locomotory and physiological responses induced by clove and cinnamon essential oils in the maize weevil Sitophilus zeamais.
abstract: Plant essential oils have been suggested as a suitable alternative for controlling stored pests worldwide. However, very little is known about the physiological or behavioral responses induced by these compounds in insect populations that are resistant to traditional insecticides. Thus, this investigation evaluated the toxicity (including the impacts on population growth) as well as the locomotory and respiratory responses induced by clove, Syzygium aromaticum L., and cinnamon, Cinnamomum zeylanicum L., essential oils in Brazilian populations of the maize weevil Sitophilus zeamais. We used populations that are resistant to phosphine and pyrethroids (PyPhR), only resistant to pyrethroids (PyR1 and PyR2) or susceptible to both insecticide types (SUS). The PyPhR population was more tolerant to cinnamon essential oil, and its population growth rate was less affected by both oil types. Insects from this population reduced their respiratory rates (i.e., CO2 production) after being exposed to both oil types and avoided (in free choice-experiments) or reduced their mobility on essential oil-treated surfaces. The PyR1 and PyR2 populations reduced their respiratory rates, avoided (without changing their locomotory behavior in no-choice experiments) essential oil-treated surfaces and their population growth rates were severely affected by both oil types. Individuals from SUS population increased their mobility on surfaces that were treated with both oil types and showed the highest levels of susceptibility to these oils. Our findings indicate that S. zeamais populations that are resistant to traditional insecticides might have distinct but possibly overlapping mechanisms to mitigate the actions of essential oils and traditional insecticides.
authors.affiliation: Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil.
authors.forename: Yenis Del Carmen
authors.initials: Ydel C
authors.lastname: Gonzales Correa
authors.affiliation: Departamento de Engenharia Agrícola, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil. Electronic address: lfaroni@ufv.br.
authors.forename: Lêda R A
authors.initials: LR
authors.lastname: Faroni
authors.affiliation: Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil; Science without Border Associate Researcher, Programa de Pós-Graduação em Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil.
authors.forename: Khalid
authors.initials: K
authors.lastname: Haddi
authors.affiliation: Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil. Electronic address: eugenio@ufv.br.
authors.forename: Eugênio E
authors.initials: EE
authors.lastname: Oliveira
authors.affiliation: Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil.
authors.forename: Eliseu José G
authors.initials: EJ
authors.lastname: Pereira
mesh_terms: D000818:Animals; D002935:Cinnamomum zeylanicum / Q000737:chemistry*; D007306:Insecticides / Q000494:pharmacology*; D008124:Locomotion / Q000187:drug effects; D009822:Oils, Volatile / Q000494:pharmacology*; D010571:Pest Control; D010935:Plant Diseases / Q000469:parasitology; D010938:Plant Oils / Q000494:pharmacology*; D027842:Syzygium / Q000737:chemistry*; D048889:Weevils / Q000187:drug effects* / Q000502:physiology; D003313:Zea mays / Q000469:parasitology*
chemical_list: D007306:Insecticides; D009822:Oils, Volatile; D010938:Plant Oils
keywords: Botanical insecticides; Cinnamomum zeylanicum; Insect body mass; Respiratory rates; Syzygium aromaticum