Resumo -O objetivo deste trabalho foi avaliar a preferência alimentar de adultos do bicudo-do-algodoeiro, Anthonomus grandis Boheman, 1843 (Coleoptera: Curculionidae), por duas cultivares de algodão (Gossypium hirsutum L.) com frutos de diferentes idades. Foram realizados quatro experimentos em laboratório, avaliando-se o número de orifícios de alimentação. Maçãs de 2, 8 e 12 dias de idade, das cultivares IAC-20 e Reba P288, foram oferecidas aos insetos, confinados em recipientes, com opção de escolha quanto à idade e cultivar (primeiro experimento), sem opção de escolha quanto à idade e cultivar (segundo experimento), sem opção de escolha quanto à cultivar e com opção quanto a idade (terceiro experimento) e sem opção quanto à idade e com opção de escolha quanto à cultivar (quarto experimento). Observou-se preferência por maçãs da cultivar IAC-20 com dois dias de idade, com uma redução de danos de 23,53% e 78,43%, respectivamente, aos oito e aos doze dias de idade.Termos para indexação: Anthonomus grandis, Gossypium hirsutum, pragas de plantas, dano, algodão. Boll weevil feeding preference for fruits of cotton cultivars at different agesAbstract -The objective of this work was to assess the boll weevil, Anthonomus grandis Boheman, 1843 (Coleoptera: Curculionidae) feeding preference for fruits of two cotton cultivars at different ages. The number of feeding holes was assessed in four laboratory experiments. Cotton bolls from cultivars IAC-20 and Reba P288, at the age of 2, 8 and 12 days were offered to the insects, confined in recipients, with (first experiment) and without (second experiment) possibilities of choice both age and cultivar; without possibilities of choice concerning cultivar and with possibilities of choice concerning age (third experiment); without possibility of choice concerning age and with possibility of choice concerning cultivar (fourth experiment). Boll weevil showed preference for the fruits of IAC-20 cultivar. Insect fed more frequently on fruits at the age of two days, with damage reduction of 23.53% and 78.43% on fruits at the age of 8 and 12 days, respectively.

The black angico (Anadenanthera macrocarpa) contains some phenolic compounds, such as flavonoids and tannins, which are considered as secondary metabolites with antimicrobial properties and can be used in the nematodes management. The experimental design was completely randomized in a factorial (2 x 5) + 1 (leaf and bark x concentrations (20, 40, 60, 80 and 100 g L -1 ) + control water-only), with five replications. The cotton seedlings were inoculated with suspension of 4,400 juveniles and eggs of M. incognita. The extracts were applied on soil in a total of 100 mL per pot, in four installments of 25 mL each, in intervals of 15 days . After 60 days of the extracts application, agronomic parameters and parasitism characterist ics were evaluated. Plant height and fresh mass of aerial part presented considerable gain with application of leaf extracts. All extracts, regardless of concentration, showed independent suppressive effect to M. incognita. The black angico extracts presented potential capacity to control gall nematodes by the presence of metabolite compounds that affect the plants protection. These results reinforce the need of further studies regarding the isolation of chemical compounds with nematicide action.

Vinasse, a byproduct result of the process of distillation and fermentation of sugar cane in the ethanol production, stands out for high availability and nutritional alternative source in pest control. The objective of this study was to evaluate the vinasse potential applied to soil, aiming at the control of Pratylenchus brachyurus in soybean crop. The experimental design was a completely randomized factorial (2 × 11), consisting of two forms of application of vinasse (single and divided into two), in eleven concentrations (0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100%), with five replications. The soybean plants were inoculated with a suspension of 4,000 eggs/juveniles of P. brachyurus. 60 days after the first application of vinasse, agronomic variables and parasitism were evaluated. The single vinasse application promoted greater growth and root development. Regarding the nematodes parasitism, the application divided was more efficient in the reduction of juveniles in the root and soil, where the concentrations of vinasse enough to reduce the population of 50% (CL50) of the nematodes were 10.22% and 16.64%, respectively. Whereas, for the other variables such as: nematodes per gram of roots (73.97%), eggs in the root (86%) and total nematodes in roots and soil (67.90%), the greatest reduction was observed in the 20% concentration of vinasse. Therefore, vinasse shows potential as a nematicide, as well as excellent organic fertilizer.

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