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Predação de larvas de traça-do-tomateiro pelos mirídeos Dicyphus cerastii e Nesidiocoris tenuis
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Resumo(s)
A traça-do-tomateiro, Phthorimaea absoluta Meyrick (Lepidoptera: Gelechiidae), é uma praga invasora que se posicionou rapidamente como praga-chave na bacia do Mediterrâneo, pelo seu potencial para destruir até 100% da produção de tomate, pela reprodução rápida e capacidade de adquirir rapidamente resistência a inseticidas. Uma gestão adequada deste inimigo exige a integração de meios de proteção, sendo o uso de mirídeos predadores (Hemiptera; Miridae) da tribo Dicyphini uma ferramenta valiosa, especialmente em cultura protegida. Estes mirídeos são predadores generalistas que suplementam a sua dieta com a alimentação em tecidos vegetais, o que lhes confere resiliência e a capacidade de se estabelecerem na cultura mesmo em condições de escassez de presas, mas que pode, no entanto, causar estragos substanciais na cultura.
Esta dissertação teve como objetivo comparar a eficácia no consumo de larvas de P. absoluta de dois mirídeos predadores, Nesidiocoris tenuis (Reuter), usado comercialmente para largadas em estufa, e Dicyphus cerastii Wagner, de ocorrência espontânea na Península Ibérica.
Comparou-se a eficácia entre fêmeas adultas e ninfas de D. cerastii e entre fêmeas adultas de D. cerastii e de N. tenuis, para todos os instares larvares de P. absoluta, e para as posições da larva, dentro e fora da mina. Não se verificaram diferenças significativas nos níveis de predação entre as espécies de predador, mas verificaram-se diferenças significativas na predação dentro versus fora da mina e entre instares larvares, para todos os predadores, sendo que a predação é atenuada pela proteção conferida pela mina e pelo aumento do tamanho da presa. Houve clara preferência pelo instar L1 e por larvas fora da mina, para todos os predadores avaliados. O tamanho ligeiramente superior de D. cerastii não se revelou vantajoso no consumo de presas de maior tamanho quando comparado com N. tenuis. Os predadores foram igualmente eficazes no consumo de larvas, mas a eficácia das duas espécies foi baixa.
The tomato leafminer, Phthorimaea absoluta Meyrick (Lepidoptera: Gelechiidae), is an invasive pest which quickly became a key pest in the Mediterranean basin, due to it’s potential to destroy up to 100% of the tomato yield, fast reproduction and ability to quickly develop insecticide resistance. Adequate management of this pest requires the implementation of integrated protection measures and the deployment of generalist predatory mirids (Hemiptera: Miridae) from the Dicyphini tribe is a valuable tool, especially in protected crops. These mirids supplement their diet by feeding on plant tissues, which grants them more resilience and the ability to establish in the crop even in conditions of prey scarcity; however, this behaviuor can cause substantial damage to the crop. This dissertation aimed to compare the efficacy of two predator mirids on their consumption of P. absoluta larvae: Nesidiocoris tenuis (Reuter), commercially used in augmentative releases in greenhouses, and Dicyphus cerastii Wagner, naturally occurring in the Iberian Peninsula. We compared the efficacy between D. cerastii adult females and nymphs and between adult females of D. cerastii and N. tenuis, for all instars of P. absoluta larvae and for the larvae’s position either inside or outside a mine. No difference was found in predation levels between these predator species in the same conditions. Differences were found between the positions inside versus outside the mine and between larval instars, within all predator categories. All predators showed clear preference for smaller larvae and larvae outside the mine. D. cerastii is slightly bigger than N. tenuis but this didn’t prove advantageous in the consumption of larger prey. All predators proved similarly effective in P. absoluta larvae consumption, but both species presented low efficacy.
The tomato leafminer, Phthorimaea absoluta Meyrick (Lepidoptera: Gelechiidae), is an invasive pest which quickly became a key pest in the Mediterranean basin, due to it’s potential to destroy up to 100% of the tomato yield, fast reproduction and ability to quickly develop insecticide resistance. Adequate management of this pest requires the implementation of integrated protection measures and the deployment of generalist predatory mirids (Hemiptera: Miridae) from the Dicyphini tribe is a valuable tool, especially in protected crops. These mirids supplement their diet by feeding on plant tissues, which grants them more resilience and the ability to establish in the crop even in conditions of prey scarcity; however, this behaviuor can cause substantial damage to the crop. This dissertation aimed to compare the efficacy of two predator mirids on their consumption of P. absoluta larvae: Nesidiocoris tenuis (Reuter), commercially used in augmentative releases in greenhouses, and Dicyphus cerastii Wagner, naturally occurring in the Iberian Peninsula. We compared the efficacy between D. cerastii adult females and nymphs and between adult females of D. cerastii and N. tenuis, for all instars of P. absoluta larvae and for the larvae’s position either inside or outside a mine. No difference was found in predation levels between these predator species in the same conditions. Differences were found between the positions inside versus outside the mine and between larval instars, within all predator categories. All predators showed clear preference for smaller larvae and larvae outside the mine. D. cerastii is slightly bigger than N. tenuis but this didn’t prove advantageous in the consumption of larger prey. All predators proved similarly effective in P. absoluta larvae consumption, but both species presented low efficacy.
Descrição
Mestrado em Engenharia Agronómica – Proteção de Plantas / Instituto Superior de Agronomia, Universidade de Lisboa
Palavras-chave
Phthorimaea absoluta tuta absoluta proteção biológica Dicyphini biological control
Contexto Educativo
Citação
Bernardo, I.M.C. Predação de larvas de traça-do-tomateiro pelos mirídeos Dicyphus cerastii e Nesidiocoris tenuis. Lisboa: ISA, 2024, 82 p. Dissertação de Mestrado
Editora
Instituto Superior de Agronomia, Universidade de Lisboa