Potencial do ácaro predador Protogamasellopsis zaheri (Rhodacaridae) no controle do fitonematoide Meloidogyne incognita (Meloidogynidae)
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Data
2023-02-16
Autores
Prado, Thais Juliane do
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Universidade Estadual Paulista (Unesp)
Resumo
O nematoide-das-galhas, Meloidogyne incognita (Kofoid & White), é um dos mais importantes itonematoides no mundo devido sua alta capacidade de parasitismo em diversos cultivos agrícolas e seu difícil controle. O controle biológico com ácaros predadores edáficos vem se mostrando uma opção no manejo de fitonematoides. O ácaro predador Protogamasellopsis zaheri Abo-Shnaf, Castilho & Moraes (Mesostigmata: Rhodacaridae), encontrado em diferentes regiões do Brasil, tem se mostrado promissor como agente de controle de M. incognita em laboratório. O objetivo da presente tese foi verificar o potencial do ácaro predador P. zaheri no manejo do fitonematoide, M. incognita, por meio de estudos em laboratório e casa de vegetação. Os objetivos específicos foram: 1) avaliar o ciclo de vida do predador ao se alimentar de ovos do fitonematoide, e verificar se é uma presa adequada ao seu desenvolvimento e reprodução; 2) avaliar o potencial de predação do predador sobre juvenis de segundo estádio (J2) do fitonematoide e sobre o nematoide de vida livre Rhabditella axei (Cobbold); 3) avaliar o potencial do predador como agente de controle biológico de M. incognita em tomateiro cultivado em casa-de-vegetação, com ou sem a liberação conjunta de R. axei; 4) verificar, em condições de laboratório, se produtos fitossanitários empregados em diferentes cultivos agrícolas são seletivos ou prejudiciais ao predador; e (5) prever possíveis variações no potencial do predador no controle do fitonematoide sob diferentes cenários de período de liberação e suplementação com nematoide de vida livre. Os resultados obtidos demostraram que: 1) O predador foi capaz de completar o seu ciclo de vida e se reproduzir ao se alimentar de ovos de M. incognita; 2) Uma fêmea de P. zaheri predou em média cerca de 318 J2 de M. incognita ou 72 machos adultos de R. axei por dia; 3) A liberação de P. zaheri em tomateiro infestados pelo parasito diminuiu a população de M. incognita em até 51%. A maior média de produção de frutos de tomate por planta foi observada no grupo de plantas em que o predador foi liberado juntamente com o nematoide de vida livre; 4) Dentre os produtos fitossanitários testados, os herbicidas Hexazinona, Indaziflam e Flumioxazina, e os inseticidas Bacillus thuringiensis (microbiológico) e Tiametoxam foram seletivos ao ácaro predador; 5) O cenário combinando uma única liberação precoce de P. zaheri com uma inoculação tardia de R. axei, duas semanas após, foi predito como o mais eficiente ao manejo do parasita assim como liberações periódicas do predador. O presente estudo adicionou novo suporte ao potencial de P. zaheri como agente de controle de M. incognita, principalmente quando utilizado nematoide vida livre como alimento suplementar para esse ácaro predador.
The root-knot nematode, Meloidogyne incognita (Kofoid & White), is one of the most important nematodes in the world due to its high capacity of parasitism in several agricultural crops and its difficult control. The biological control of plantparasitic nematode with edaphic predatory mites has been proving to be an option. The predatory mite Protogamaselopsis zaheri Abo-Shnaf, Castilho & Moraes (Mesostigmata: Rhodacaridae), found in different parts of Brazil, has shown promise as a control agent for M. incognita in laboratory studies. The aim of this thesis was to verify the potential of the predatory mite P. zaheri in the management of the plantnematode M. incognita through laboratory and greenhouse studies. The specific objectives were: 1) to evaluate the life cycle of the predator when feeding on M. incognita egg’s and determine if it is a suitable prey for its development and reproduction; 2) to assess the predation potential of the predator on second-stage juveniles of M. incognita (J2) and the free-living nematode Rhabditella axei (Cobbold); 3) to evaluate the potential of the predator as a biological control agent of M. incognita in tomato plants grown in a greenhouse, with or without the simultaneous release of R. axei; 4) to verify, under laboratory conditions, whether phytosanitary products used in different agricultural crops are selective or harmful to the predator; and 5) to predict possible variations in the potential of the predator for controlling the plant-parasitic nematode under different scenarios of release period and supplementation with freeliving nematodes. The results demonstrated that: 1) The predator was able to complete its life cycle and reproduce when feeding on M. incognita eggs; 2) A female P. zaheri preyed on average about 318 J2 of M. incognita or 72 adult males of R. axei per day; 3) The release of P. zaheri in tomato plants infested by M. incognita decreased the population of the nematode by up to 51%. The highest average production of tomato fruits per plant was observed in the group of plants in which the predator was released together with the free-living nematode; 4) Among the tested phytosanitary products, the herbicides Hexazinone, Indaziflam, and Flumioxazin, and the insecticides Bacillus thuringiensis (microbiological) and Thiamethoxam were selective to the predator mite; 5) The scenario combining a single early release of P. zaheri with a late inoculation of R. axei, two weeks later, was predicted to be the most efficient for nematode management, as well as periodic releases of the predator. This study provided additional evidence to support the potential of P. zaheri as a biological control agent of M. incognita, especially when supplemented with free-living nematodes as a food source for this predatory mite.
The root-knot nematode, Meloidogyne incognita (Kofoid & White), is one of the most important nematodes in the world due to its high capacity of parasitism in several agricultural crops and its difficult control. The biological control of plantparasitic nematode with edaphic predatory mites has been proving to be an option. The predatory mite Protogamaselopsis zaheri Abo-Shnaf, Castilho & Moraes (Mesostigmata: Rhodacaridae), found in different parts of Brazil, has shown promise as a control agent for M. incognita in laboratory studies. The aim of this thesis was to verify the potential of the predatory mite P. zaheri in the management of the plantnematode M. incognita through laboratory and greenhouse studies. The specific objectives were: 1) to evaluate the life cycle of the predator when feeding on M. incognita egg’s and determine if it is a suitable prey for its development and reproduction; 2) to assess the predation potential of the predator on second-stage juveniles of M. incognita (J2) and the free-living nematode Rhabditella axei (Cobbold); 3) to evaluate the potential of the predator as a biological control agent of M. incognita in tomato plants grown in a greenhouse, with or without the simultaneous release of R. axei; 4) to verify, under laboratory conditions, whether phytosanitary products used in different agricultural crops are selective or harmful to the predator; and 5) to predict possible variations in the potential of the predator for controlling the plant-parasitic nematode under different scenarios of release period and supplementation with freeliving nematodes. The results demonstrated that: 1) The predator was able to complete its life cycle and reproduce when feeding on M. incognita eggs; 2) A female P. zaheri preyed on average about 318 J2 of M. incognita or 72 adult males of R. axei per day; 3) The release of P. zaheri in tomato plants infested by M. incognita decreased the population of the nematode by up to 51%. The highest average production of tomato fruits per plant was observed in the group of plants in which the predator was released together with the free-living nematode; 4) Among the tested phytosanitary products, the herbicides Hexazinone, Indaziflam, and Flumioxazin, and the insecticides Bacillus thuringiensis (microbiological) and Thiamethoxam were selective to the predator mite; 5) The scenario combining a single early release of P. zaheri with a late inoculation of R. axei, two weeks later, was predicted to be the most efficient for nematode management, as well as periodic releases of the predator. This study provided additional evidence to support the potential of P. zaheri as a biological control agent of M. incognita, especially when supplemented with free-living nematodes as a food source for this predatory mite.
Descrição
Palavras-chave
Ácaro de solo, Controle biológico, Dinâmica populacional, Mesostigmata, Nematoide de vida livre, Seletividade