Cholesterol oxidase interference on the emergence and viability of cotton boll weevil larvae

The aim of this work was to evaluate the influence of the enzyme cholesterol oxidase (Coase) on emergence and viability of larvae of the cotton boll weevil (Anthonomus grandis Boheman, 1843). A series of bioassays was performed with eggs and neonate larvae exposed to different enzyme concentrations in artificial diet. Larval survival was affected at all enzyme concentrations tested, and the six-day LD50 was 53 mug/mL (CI 95%: 43-59). Coase also interfered with hatching of larvae after eggs were floated for 15 min in Coase solution at different concentrations. Observations at the light and electronic microscopic level of midguts from larvae fed on artificial diet containing 53 mug/mL of Coase and collected at six days revealed highly vacuolated regions in the epithelial cells as well as partial degradation of the basal membrane and microvilli.

Mechanical damage in cotton buds caused by the boll weevil

The boll weevil (Anthonomus grandis Boheman) causes high levels of bud abscission in cotton plants due to feeding or oviposition punctures. It has been reported that abscission is mainly due to enzymes present in the insect's saliva, but mechanical damage could also contribute to square abscission. The objective of this paper was to undertake an analysis of the morphological damages caused by the insect in cotton squares using microscopy. Anthers and ovules are the main target of boll weevil feeding. The process initiates by perforation of young sepal and petal tissues and proceeds with subsequent alimentation on stamen and ovary leading to abscission of floral structures.

Effect of diameter of the cotton squares in the development of boll weevil

O objetivo deste trabalho foi estudar o efeito do diâmetro dos botões florais de algodoeiro na massa corporal de adultos do bicudo-do-algodoeiro, Anthonomus grandis Boheman (Coleoptera: Curculionidae). O experimento foi realizado em condições de campo e laboratório, em Jaboticabal (SP), Brasil. Foram realizadas seis amostragens, coletando-se ao acaso dez plantas nas cultivares Coodetec 405 e Fibermax 986, avaliando-se o número e o diâmetro de botões florais. Os botões florais com orifícios de oviposição foram individualizados em frascos e observados diariamente para a visualização da emergência dos adultos. Botões florais com maiores diâmetros proporcionam maior massa corporal de adultos de A. grandis recém-emergidos nas duas cultivares.

Between-season attraction of cotton boll weevil, Anthonomus grandis Boh. (Coleoptera: Curculionidae) adults by its aggregation pheromone

O presente estudo teve como objetivo investigar a atratividade do bicudo do algodoeiro ao seu feromônio de agregação em período de inverno. Foram utilizados dois campos experimentais no município de Casa Branca, SP. em cada um destes, foram estabelecidas três áreas separadas de aproximadamente 500 metros, sempre próximas à vegetação de refúgio. Cada área foi dividida em três sub-áreas ou blocos de 100 m² para receber a aplicação do feromônio (2,5 g por bloco). Foi realizada uma contagem de bicudos adultos no solo antes, e mais cinco após a aplicação de feromônio. em cada bloco, foram observadas dez parcelas aleatórias, para a avaliação dos bicudos. Os adultos de A. grandis foram atraídos imediatamente após a aplicação do feromônio, sendo capturados por mais de 14 dias após. O índice mais elevado de atração foi observado 24 horas após a aplicação. A utilização do feromônio de agregação durante o inverno, pode aumentar a ação reguladora exercida pelos inimigos naturais, devido ao aumento de disponibilidade de presas. Controle químico pode ser recomendado 24 horas após a aplicação de feromônio em pequenas parcelas, como uma estratégia para a supressão de adultos de Anthonomus grandis em período de entressafra.

PHEIDOLE ANTS AS POTENTIAL BIOLOGICAL-CONTROL AGENTS OF THE BOLL-WEEVIL, ANTHONOMUS-GRANDIS (COL, CURCULIONIDAE), IN SOUTHEAST BRAZIL

This study evaluates the potential of ants as natural biological control agents of the boil weevil (Anthonomus grandis), during the between-season period, in South-east Brazil. Active adults of Anthonomus were experimentally distributed on the ground of the cotton field. Results show that 20% of the adult Anthonomus are attacked and removed by foraging ants. The native ant Pheidole oliveirai was by far the most efficient predator, accounting for 94% of the predation on Anthonomus. Recruited workers of P. oliveirai were usually very fast at transporting the weevils to their nests. The potential benefit of suppressing overwintering adult Anthonomus during the between-season period is mainly that of reducing the risk of high level infestations during the next cropping cycle.

The boll weevil: how to control it.

"This edition replaces all previous editions of this publication. Because of changed insecticide recommendations, earlier copies are obsolete."

Boll weevil populations as affected by removal of shed cotton forms /

Mode of access: Internet.

Cotton boll weevil : Anthonomus grandis Boh. : Abstracts of research publications, 1843-1960 /

Includes index.

Boll weevil, Anthonomus grandis Boh., abstracts of research publications, 1961-65.

Continuation of Cotton boll weevil (Anthonomus grandis Boh.) abstracts of research publications, 1843-1960, by Henry A. Dunn, issued as Miscellaneous publication no. 985.

Ecological investigations of the boll weevil, Tallulah, Louisiana, 1915-1958 /

Literature cited: p. 19-20.

Chemosterilants screened against the boll weevil in dipping and feeding tests /

"In cooperation with Mississippi Agricultural Experiment Station."

The integration of selected boll weevil suppression techniques in an eradication experiment /

"In cooperation with Texas Agricultural Experiment Station."

Survival and preference of cotton boll weevil adults for alternative food sources.

2016

Cotton or boll weevils /

Cover title.

Within plant distribution of Anthonomus grandis (Coleoptera: Curculionidae) feeding and oviposition damages in cotton cultivars

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)