title: Toxicity of Piper aduncum (Piperaceae) Essential Oil Against Euschistus heros (F.) (Hemiptera: Pentatomidae) and Non-Effect on Egg Parasitoids.
abstract: Plant essential oils have been recognized as significant natural resources for insecticides. Herein, we have assessed the toxicity of the essential oil of Piper aduncum (Piperaceae) against Euschistus heros (F.) (Hemiptera: Pentatomidae), a key soybean pest in Neotropical America. In addition, we have assessed its effect on the performance of egg parasitoids. The essential oil was obtained from the leaves of P. aduncum via hydrodistillation. Subsequently, bioassays of the concentration response to eggs (contact and immersion methods), nymphs, and adults (topical application) were conducted, to assess the lethal effects on the stink bug. We also evaluated the performance of parasitism and adult emergence of egg parasitoids, when the host eggs were treated with essential oil. In the egg bioassay, both exposure methods were efficient for unviable eggs (immersion LC50= 15.64 mg mL-1; contact LC50= 21.29 mg mL-1), with the highlight on the immersion method. The bioassay with nymphs indicated a higher toxicity of essential oil, with lower concentrations (LC50= 11.37 mg mL-1) being required to cause the death of insects. For adults, a reduction in survival of insects was observed, and consequently, there was a reduction in the number of individuals in the next generation. Although the essential oil was toxic to E. heros, it exhibited lower toxicity for egg parasitoids, as there was no effect on parasitism and the emergence of wasps. We discuss likely explanations for such selectivity. In summary, we found that the essential oil was promising for the control of E. heros, because it caused deleterious effects at all development stages of the stink bug and had no effect on parasitism and emergence of the egg parasitoids, which suggested compatibility with biological control.
authors.affiliation: Dept of Entomology, Univ Federal de Viçosa, Viçosa, MG, Brasil. leonardo.turchen@ufv.br.|Depto de Entomologia, Programa de Pós Graduação em Entomologia, Univ Federal de Viçosa, Viçosa, MG, 36570-000, Brasil. leonardo.turchen@ufv.br.
authors.forename: L M
authors.initials: LM
authors.lastname: Turchen
authors.affiliation: Dept of Agronomy, Univ do Estado de Mato Grosso, Tangará da Serra, MT, Brasil.
authors.forename: L P
authors.initials: LP
authors.lastname: Piton
authors.affiliation: Dept of Chemistry, Univ Federal do Mato Grosso, Cuiabá, MT, Brasil.
authors.forename: E L
authors.initials: EL
authors.lastname: Dall'Oglio
authors.affiliation: Dept of Agronomy, Univ do Estado de Mato Grosso, Tangará da Serra, MT, Brasil.
authors.forename: A R
authors.initials: AR
authors.lastname: Butnariu
authors.affiliation: Dept of Agronomy, Univ do Estado de Mato Grosso, Tangará da Serra, MT, Brasil.
authors.forename: M J B
authors.initials: MJ
authors.lastname: Pereira
mesh_terms: D000818:Animals; D006430:Hemiptera / Q000254:growth & development / Q000469:parasitology; D020062:Heteroptera; D009758:Nymph; D009822:Oils, Volatile / Q000494:pharmacology*; D010571:Pest Control; D031701:Piper / Q000737:chemistry*; D014863:Wasps / Q000472:pathogenicity
chemical_list: D009822:Oils, Volatile
keywords: Biological control; brown stink bug; phytoinsecticide; selectivity; sustainable pest control