Mestrado em Agronomia (EA)
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Navegando Mestrado em Agronomia (EA) por Por Orientador "Barrigossi, José Alexandre Freitas"
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Item Resistência a inseticidas em populações de percevejo-do-colmo do arroz Tibraca limbativentris (hemiptera: pentatomidae)(Universidade Federal de Goiás, 2016-09-13) Maciel, Diogo Nery; Fragoso, Daniel de Brito; http://lattes.cnpq.br/4162628180188621; Barrigossi, José Alexandre Freitas; http://lattes.cnpq.br/5377957113836597; Barrigossi, José Alexandre de Freitas; Fragoso, Daniel de Brito; Aguiar, Raimundo Wagner de Souza; Araújo, Leila Garcês deThe increase in insecticide application for control the rice stalk stink bug Tibraca limbativentris Stal (Hemiptera: Pentatomidae) in irrigated rice in Brazil, has been reported by producers as responsible for loss of effectiveness of some insecticides commonly used to manage this insect and this is the base of this investigation. The insecticides used in this study were: bifenthrin, carbosulfan, etophenprox, λ-cyhalothrin, and thiametoxam. Six populations of insects were collected in producing areas of the states of Tocantins, Goiás and Santa Catarina, Brazil. Insect adults of each population were submitted to discriminant concentrations (LC95s) previously determined for the population collected in natural habitat in Santo Antônio de Goiás, and used as standard susceptible population. The frequency of individuals resistant in the population of Formoso do Araguaia was 76% for carbosulfan, 86% for bifenthrin, 72% for etofenprox, 80% for L-cyalothrin, and 80% for thyamethoxam. Although the frequencies of resistant individuals can be considered low to moderate, it is first report of resistance of T. limbativentris to insecticides. These results indicate the resistance development to other insecticides with different mode of actions, with emphasis to the stink bug populations of Formoso do Araguaia-TO. These results also indicates a possible occurrence of crossed a resistance or multiple in that population.Item Influência de semioquímicos emitidos por plantas de arroz no comportamento de Tibraca limbativentris, Glyphepomis spinosa (Heteroptera: Pentatomidae) e Telenomus podisi (Hymenoptera: platygastridae)(Universidade Federal de Goiás, 2018-04-18) Ulhoa, Lucas Adjuto; Moraes, Maria Carolina Blassioli; http://lattes.cnpq.br/6269532115803649; Barrigossi, José Alexandre Freitas; http://lattes.cnpq.br/5377957113836597; Barrigossi, José Alexandre Freitas; Magalhães, Diego Martins; Laumann, Raul AlbertoTibraca limbativentris Stål is one of the stink bugs most harmful to rice cultivation in Brazil, mainly in irrigated environment. Glyphepomis spinosa Campos & Grazia is a stink bug of secondary economic importance, but often occurs in rice fields in the Midwestern and Northern regions of Brazil. To defend against these stink bugs, plants can emit volatile organic compounds that act directly as repellent or as toxic substances, or indirectly, by attracting natural enemies. Studies on chemical communication between insects and plants are fundamental to understand the host searching process, and can be used to manage insect pests and natural enemies in the field. The objectives of this work were to identify the constitutive and herbivore - induced volatile organic compounds emitted by rice and to evaluate the influence of these volatiles on the searching behavior of the stink bugs T. limbativentris and G. spinosa and their natural enemy, the egg parasitoid Telenomus podisi Ashmead. The volatiles were collected from rice (BRS Pampa) without injury and with injury imposed by two virgin females (adults) of T. limbativentris and G. spinosa, for up to 144 hours. The samples were analyzed by gas chromatography coupled to a flame ionization detector (CG-FID) and gas chromatography coupled to mass spectrometry (GC-MS). The responses of virgin and mated females of T. limbativentris and G. spinosa and virgin females of T. podisi were evaluated in a "Y-tube" olfactometer. The rice plants responded to injury producing volatiles, especially the sesquiterpenoids. Virgin females of T. limbativentris preferred heathy plants and air (control without plants) than by injured plants. Virgin females of G. spinosa females preferred air than by injured plants. The egg parasitoids T. podisi preferred injured plants by T. limbativentris than by healthy plants. T. podisi also preferred injured plants by G. spinosa than by air. The results show that rice plants release defense compounds that act directly repelling the stink bugs T. limbativentris and G. spinosa and indirectly attracting the natural enemy T. podisi.