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Abstract(s)
A mosca-branca-do-feijoeiro (Bemisia tabaci) e a traça-do-tomateiro (Tuta absoluta) são duas
pragas que assolam culturas de tomate (Solanum lycopersium) em todo o mundo. Mirídeos (Hemiptera:
Miridae) são usados como controlo biológico destas pragas. Estes insetos possuem comportamento
zoofitófago (alimentam-se de plantas e invertebrados), sendo, por isso, capazes de controlar as pragas
e, posteriormente, sobreviver na cultura. Contudo, a alimentação das plantas por parte dos mirídeos
causa, muitas vezes, estragos. Nesidiocoris tenuis, um dos mirídeos usados no controlo biológico,
provoca anéis necróticos no caule, podendo levar à rejeição do fruto. De forma a minimizar este
problema, podem ser colocadas outras espécies de plantas dentro da cultura ou na sua vizinhança,
denominadas plantas “insectário”, cujo papel é atraírem os mirídeos e servirem de alimento vegetal para
estes, prevenindo estragos no tomate. Neste estudo, testou-se o potencial de seis espécies de plantas
(alisso-doce, bocas-de-lobo, calêndula, facélia, tabaco e tomate) para servirem como plantas “insectário”
para duas espécies de mirídeos, Dicyphus cerastii e Nesidiocoris tenuis.
Das seis espécies de plantas testadas, o tomate foi a planta mais escolhida para postura, enquanto
o alisso-doce (Lobularia maritima) obteve os resultados mais baixos para ambos os mirídeos. Calêndula
(Calendula officinalis) mostrou ser um potencial hospedeiro de D. cerastii, visto ter tido o segundo
maior número de ninfas observadas desta espécie, por outro lado, N. tenuis preferiu o tabaco (Nicotiana
tabacum). Nas bocas-de-lobo (Antirrhinum cirrhigerum) obteve-se um número baixo de ninfas com D.
cerastii, mas um número mais alto com N. tenuis, o que indica que esta planta pode ser um potencial
hospedeiro para este último.
Mais estudos devem ser realizados e com um maior número de espécies de plantas para se
identificar as melhores plantas insectário para cada espécie de mirídeo. A flor deverá estar também
presente, pois esta tem um papel importante na atração dos insetos.
The silverleaf whitefly (Bemisia tabaci) and South American tomato leafminer (Tuta absoluta) are two pests that ravage tomato cultures around the world. Mirids (Hemiptera: Miridae) are used as biological control of these pests. These insects display zoophytophagous behaviour, meaning that they feed on both plants and insects alike. This allows them to control these pests and persist in the crop through plant feeding. However, this feeding behaviour damages the plants. Nesidiocoris tenuis, one of the species used in control programs, induces necrotic rings on the stem and it may even lead to flower or fruit abortion. Therefore, to minimize these damages, other plant species can be placed within the crop field or its margins. These plants are called “insectary” plants whose purpose is to attract the mirids and allow them to feed on the plants, keeping them away from the tomato plant in the absence of pests. In this study, we verified the potential of six different plant species (daisy, lacy phacelia, snapdragon, sweet-alyssum, tobacco and tomato) to serve as “insectary” plants for two mirid species, Dicyphus cerastii and Nesidiocoris tenuis. Tomato (Solanum lycopersium) proved to be the favourite plant to oviposit while sweet alyssum (Lobularia maritima) showed the worst results for both mirid species. Daisy (Calendula officinalis) was the second preferred plant for D. cerastii, while N. tenuis preferred tobacco (Nicotiana tabacum) as its second choice. Snapdragon (Antirrhinum cirrhigerum) had the second lowest number of nymphs for D. cerastii but the third highest for N. tenuis, which indicates this plant might be a potential insectary plant for the latter. Further studies need to be done to accurately assert a plant’s potential as an insectary plant. More species of plants should be tested with the presence of the plant’s own flowers since they play an important role in insect attraction.
The silverleaf whitefly (Bemisia tabaci) and South American tomato leafminer (Tuta absoluta) are two pests that ravage tomato cultures around the world. Mirids (Hemiptera: Miridae) are used as biological control of these pests. These insects display zoophytophagous behaviour, meaning that they feed on both plants and insects alike. This allows them to control these pests and persist in the crop through plant feeding. However, this feeding behaviour damages the plants. Nesidiocoris tenuis, one of the species used in control programs, induces necrotic rings on the stem and it may even lead to flower or fruit abortion. Therefore, to minimize these damages, other plant species can be placed within the crop field or its margins. These plants are called “insectary” plants whose purpose is to attract the mirids and allow them to feed on the plants, keeping them away from the tomato plant in the absence of pests. In this study, we verified the potential of six different plant species (daisy, lacy phacelia, snapdragon, sweet-alyssum, tobacco and tomato) to serve as “insectary” plants for two mirid species, Dicyphus cerastii and Nesidiocoris tenuis. Tomato (Solanum lycopersium) proved to be the favourite plant to oviposit while sweet alyssum (Lobularia maritima) showed the worst results for both mirid species. Daisy (Calendula officinalis) was the second preferred plant for D. cerastii, while N. tenuis preferred tobacco (Nicotiana tabacum) as its second choice. Snapdragon (Antirrhinum cirrhigerum) had the second lowest number of nymphs for D. cerastii but the third highest for N. tenuis, which indicates this plant might be a potential insectary plant for the latter. Further studies need to be done to accurately assert a plant’s potential as an insectary plant. More species of plants should be tested with the presence of the plant’s own flowers since they play an important role in insect attraction.
Description
Tese de Mestrado, Biologia Humana e Ambiente, 2022, Universidade de Lisboa, Faculdade de Ciências
Keywords
Controlo biológico Dicyphus cerastii Nesidiocoris tenuis Plantas insetário Teses de mestrado - 2023