ABSTRACT:Several studies have reported the importance of phytophagy in the history of life from predator stinkbugs. However, knowledge of the nutrients acquired by these insects, from plant materials, is scarce. The phytophagy studies of zoophytophagous predators benefit biological control programs, making them more effective, since the best resources may be offered to these insects, increasing the potential for predation and, thus obtaining, success in pest control. Thus, this study investigated the development and zoophytophagy of predator Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) in eucalyptus seedlings, deficient in macronutrients. The experiment was conducted in a greenhouse and the treatments consisted of individual nitrogen omission, phosphorus, potassium, calcium, magnesium and sulfur nutrient solution, where the eucalyptus seedlings were being conducted. The pupae of Tenebrio molitor L. (Coleoptera: Teneobridae) were offered ad libitum. The results of this experiment demonstrated the importance of nutrition in plants for the development and predation of P. nigrispinus. The plants deficient in nitrogen and magnesium reduce the predation efficiency of this zoophytophagous. The omission of calcium, magnesium and sulfur adversely affected the development of this insect predator, extending its immature stages. The proper nutritional balance of the plants is essential for the success in biological control programs that use zoophytophagous predators.
The objective of this study was to model the spatio-temporal distribution of Digitaria insularis (D. insularis) and analyze the risk of selection of glyphosate-resistant biotypes in eucalyptus cultivation in Brazil. Global data on the distribution of the specie were collected and associated with their ideal growth characteristics. The models were generated using Climex software, providing a predictive modeling technique. Biological data, species distribution, and climatic parameters were used to predict and map potential areas for the species of interest through the combination of growth and stress indices, giving rise to the Ecoclimatic Index (EI). The spatial distribution of D. insularis is predominantly in South and Central America and southern North America. The model had a good fit with the collected data and predicted higher EI values for tropical and subtropical regions, as was the case in Brazil. Species growth can occur throughout the year, with lower rates in winter, mainly in the country’s southern regions. Brazil has high climatic suitability for the occurrence of Digitaria insularis. Due to the climate suitability evidenced by the models and the expressive use of the same active ingredient, there is a risk of selecting glyphosate-resistant Digitaria insularis biotypes in eucalyptus cultivation areas.
Insect pests are limiting factors to the expansion of Eucalyptus spp. plantations in Brazil. Aphids of the species Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae) are a key pests in different crops and may negatively affect the growth, development and survival of plants. This paper reports the first record of M. persicae in seedlings of Eucalyptus urophylla grown in a greenhouse in Diamantina, Minas Gerais state, Brazil. This finding suggests the implementation of an integrated management program for this aphid, in order to prevent it from becoming a pest in Eucalyptus .
-Podisus nigrispinus is a generalist predator naturally occurring in agricultural and forestry systems that effectively contributes to the population balance of phytophagous insects, especially defoliating caterpillars. Histological changes were evaluated in the salivary glands and midgut of P. nigrispinus caused by ingestion of systemic herbicide isoxaflutole. These predator females were fed with leaves of eucalyptus plants, Tenebrio molitor pupae or water, contaminated or not by herbicide. Salivary glands and midguts were dissected, processed and analyzed under a light microscope. Activity level and cell morphology of the salivary glands and midgut showed differences among insects fed on plants, contaminated water or pupae. The epithelia of the salivary gland and midgut of individuals which had no contact with the herbicide showed homogeneous cytoplasm, nucleus with predominance of decondensed chromatin and evident nucleoli, intense cell activity features. As for the insects in contact with contaminated food, they presented undeveloped nucleus and condensed chromatin. The luminal contents of the salivary glands in the contaminated insects had become more acidophilus than in insects without poisoning, as well as having heterogeneous and granular secretion, being more evident in the bioassay in which the insects fed on contaminated water. There was a marked morphological change in the midgut cells in contaminated insects. High degree of apoptosis, disorganization and secretory vacuoles in the epithelial cytoplasm were observed. The apical portion of the midgut cells proved undeveloped, irregular and partially destroyed. It is concluded that isoxaflutole causes morphological changes in the digestive system of the predator P. nigrispinus.Keywords: biological control, cell apoptosis, digestive system, morphological change, Podisus nigrispinus.
RESUMO -Podisus nigrispinus é um predador generalista de ocorrência natural em sistemas agrícolas e florestais que contribui de forma efetiva para o equilíbrio populacional dos insetos fitófagos, principalmente lagartas desfolhadoras. Avaliaram-se alterações histológicas nas glândulas salivares e no intestino médio de P. nigrispinus causadas após ingestão do herbicida sistêmico isoxaflutole. Fêmeas desse predador foram alimentadas com folhas de plantas de eucalipto, pupas de Tenebrio molitor ou água, contaminados ou não pelo herbicida. As glândulas salivares e o intestino médio foram dissecados, processados e analisados em microscópio de luz. O nível de atividade e a morfologia celular das glândulas salivares e do intestino médio apresentaram diferenças conforme a alimentação. Os epitélios da glândula salivar e do intestino médio de indivíduos que não tiveram contato com o herbicida apresentaram o citoplasma homogêneo, núcleos com predomínio de cromatina descondensada e nucléolos evidentes. Já os insetos que tiveram contato com o herbicida apresentaram
Planted forests include forests established through human planting or deliberate seeding. They are systems that offer us timber and non-timber forest products and ecosystem services, such as wildlife protection, carbon sequestration, soil, and watershed maintenance. Brazil has 7.6 million hectares of planted forests, with 72% of the total area occupied by Eucalyptus spp. A favorable climate and management and genetic improvement research are the main factors responsible for high productivity. In recent years, the expansion of planted areas has been accompanied by the commercial release of several pesticides, mainly herbicides. A recent change in the Brazilian legislation allows mixing phytosanitary products in a spray tank, having a new approach to managing pests, diseases, and weeds. Antagonism is the main risk of tank mixes, and to reduce the dangers associated with this practice, we review all products registered for growing Eucalyptus. This literature review aims to identify the effects of product mixtures registered for Eucalyptus reported for other crops. In addition, environmental and social risk assessment has been widely adopted to export wood and cellulose, making the results of this review an indispensable tool in identifying the nature and degree of risks associated with pesticides. The results classify the effects of the mixtures as an additive, antagonistic or synergistic. The use of pesticide tank mixtures has the potential for expansion. However, there are still challenges regarding variations in the effects and applications in different climatic conditions. Therefore, studies that prove efficient mixtures for the forest sector are essential and the training of human resources.
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