Herein we discuss the interactions of selected species of phytophagous stink bug observed on leguminous (Fabaceae) crops in the Neotropics (Neotropical Region) with their associated plants. We included the following pentatomid species: Nezara viridula (L.), Piezodorus guildinii (Westwood), Euschistus heros (F.), Edessa meditabunda (F.), Dichelops furcatus (F.), Dichelops melacanthus (Dallas), and Thyanta perditor (F.). Based on a literature review, a list of plants on which these stink bug species were intercepted is included, indicating the reproductive hosts, i.e., plants on which bug can complete development, and incidental records, i.e., plants on which bugs are found occasionally. The change in feeding habits (from fruits/seeds of preferred host plants) to less preferred vegetative structures (stems/leaves of less preferred associated plants) for feeding or shelter, due to change in the landscape by intense multiple cropping and no-tillage cultivation systems is discussed.

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The lesser mealworm, Alphitobius diaperinus (Panzer), is an insect that lives in poultry houses, and high infestations may cause economic losses to producers. The control of this insect is usually done with insecticides; however, many of these chemicals have no effect on lesser mealworm. Therefore, control alternatives are needed. The aim of this study was to evaluate the influence of Cunila angustifolia (Benth) oil on larvae and adults of A. diaperinus. In vitro tests used larvae and adults of A. diaperinus distributed in petri dishes with 0, 1, 5, and 10% of oil in a single dose. In vivo tests were performed in poultry houses with five treatments: 0, 5, and 10% and chemical insecticide (cypermethrin) in a single application, and a group with 5% of oil applied twice 15 d apart. In vitro, oil bioactivity showed an efficacy of 100% both for larvae and adults, when tested at concentrations of 5 and 10%. A reduced number of larvae were observed using 1% of oil; however, it was not effective against adults as compared with the control group. In vivo, the oil effectiveness against lesser mealworm was verified by larva and adult reduction in all concentrations compared with control (0%) throughout the experiments, with better efficacy when used at 5% with two applications. Therefore, we concluded that the oil of C. angustifolia has larvicidal and insecticidal effect against A. diaperinus larvae and adults, in vitro and in vivo.

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ResumoA bioatividade de Cabralea canjerana (Vell.) Mart., espécie arbórea, comum na região Oeste de Santa Catarina, foi testada frente ao Acanthoscelides obtectus Say (Coleptera: Bruchidae), uma importante praga que danifica o grão do feijão. No experimento foram utilizados 10 insetos adultos, colocados em placas de Petry revestidas de papel filtro, onde foram adicionadas alíquotas de extrato bruto, fração hexânica, clorofórmica, acetato de etila e óleo essencial de folhas de C. canjerana nas concentração de 10%, 5% e 1%. O resultado em laboratório demonstrou eficiência de 100% para o extrato bruto (concentração 1%), seguido da fração hexânica (concentração 1%) com eficiência de 84,2%. As frações acetato de etila, clorofórmica e óleo essencial foram as que apresentaram as menores eficiências no controle do Acanthoscelides obtectus. Unitermos: caruncho do feijão, controle de pragas, plantas inseticidas AbstractBioactivity of Cabralea canjerana (Vell.) Mart. (Meliaceae) in the control of Acanthoscelides obtectus (Coleoptera, Bruchidae) in the laboratory. The bioactivity of Cabralea canjerana (Vell.) Mart, a common tree species in the western region of Santa Catarina, was tested with Acanthoscelides obtectus Say (Coleptera: Bruchidae), an important insect-pest that can cause damage to bean seeds. In the experiment, 10 adult insects were put onto Petry dishes lined with filter paper, to wich where was add aliquots of crude extract, hexanic, chloroformic, ethyl acetate fractions and essential oil of Cabralea canjerana leaves, concentrated in 10%, 5% and 1%, were added. The results in the laboratory showed 100% efficiency of the crude extract (concentration 1%), followed by the hexanic fraction (concentration 1%) with 84.2%. The ethyl acetate, chloroformic fractions and essential oil showed lower efficiency in the control of Acanthoscelides obtectus.