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Efeito de extrato aquoso de Strychnos pseudoquina A. St. Hil sobre Spodoptera frugiperda J.E. Smith, 1797 (Lepidoptera: Noctuidae)

Fri, 21 Jul 2023 00:00:00 GMT

Título: Efeito de extrato aquoso de Strychnos pseudoquina A. St. Hil sobre Spodoptera frugiperda J.E. Smith, 1797 (Lepidoptera: Noctuidae) Autor(es): Cavalcante, Elivelto da Silva Primeiro Orientador: Silva, Rosilda Mara Mussury Franco Abstract: The fall armyworm (Spodoptera frugiperda (J.E. Smith, 1797)) (Lepidoptera: Noctuidae) is a major pest of maize (Zea mays L.) cultivation. This cereal holds significant economic importance and is a staple in human and animal diets across all continents. In Brazil, controlling this pest has become a challenge for both small and large-scale producers. Botanical extracts are important tools in pest management, offering a sustainable and environmentally friendly approach to safeguarding agricultural crops and preserving biodiversity. The Brazilian flora provides a wide variety of plants that could be important for the production of bioinsecticides. Thus, the aim of this study was to evaluate the insecticidal potential of aqueous extracts from false quina (Strychnos pseudoquina A. St. Hil) on the biology of S. frugiperda fed on an artificial diet and on maize leaves. To achieve this, we tested the hypotheses that "the aqueous extract of S. pseudoquina may be effective in controlling S. frugiperda, with the effects of this extract in an experiment conducted with maize leaves interfering more with the life cycle of this insect than in an experiment with artificial diet." Therefore, experiments were conducted with S. frugiperda subjected to feeding on the diets; we used different concentrations (control, 5%, and 10%) of aqueous extract of S. pseudoquina, where the results obtained from the concentrations of 5% and 10% compared to the control were increased larval longevity, reductions in pupal biomass, feeding, number of days ovipositing, number, and viability of eggs, and consequently, reduction of individuals in the second generation. Therefore, we suggest that the extract of S. pseudoquina may be a viable additional alternative for use in family and organic farming; however, it is recommended that field tests be conducted using other parts of the plant and different extraction methods, which may maximize insecticidal activity as well as allow the assessment of effects on non-target organisms. Editor: Universidade Federal da Grande Dourados Tipo: Dissertação

Como o inseticida Fipronil pode impactar colônias da vespa social Polybia paulista

Fri, 07 Mar 2025 00:00:00 GMT

Título: Como o inseticida Fipronil pode impactar colônias da vespa social Polybia paulista Autor(es): Oliveira, Vinicius Edson Soares de Primeiro Orientador: Antonialli Junior, William Fernando Abstract: Phenylpyrazoles (fipronil) are a group of insecticides widely used for managing insects considered agricultural pests, due to their neurotoxic action and systemic effects on plants. However, there are no studies investigating the consequences of their use on social wasp colonies. Social wasps are generalist predators and play an important role in biological control of pest insects. In addition, they provide pollination services and may even surpass bees in both abundance and species richness as floral visitors. However, by visiting and consuming floral resources, they are also exposed to insecticides used in crops, thereby entering the same contamination pathways as bees. The objective of this study was to identify the median lethal concentration and evaluate the effects of exposure to sublethal concentrations on the survival of foragers of the social wasp Polybia paulista to the insecticide fipronil. To obtain the median lethal concentration (LC₅₀), the wasps were exposed to different concentrations of fipronil, and the LC₅₀ obtained was subsequently used as a reference for obtaining the sublethal concentrations. For survival analysis, groups of control wasps and groups of wasps exposed to sublethal concentrations were monitored until death, and the median lethal time (LT₅₀) was then calculated. The LC₅₀ after 24 hours was 0.890 ng a.i./μL (~890 ppb). Wasps exposed to any of the sublethal concentrations survived for a significantly shorter time than those in the control group. Therefore, we conclude that exposure to fipronil affects the survival of P. paulista foragers as much as the neonicotinoid insecticide thiamethoxam, and that social wasps may be as susceptible, or even more susceptible, to fipronil contamination than other commonly studied non-target insects. Editor: Universidade Federal da Grande Dourados Tipo: Dissertação

Eficiência de fungos entomopatogênicos no controle de moscas das-frutas (Diptera: Tephritidae) e gorgulho-da-goiaba (Coleoptera: Curculionidae) em plantio comercial de goiabeira Psidium guajava L. 1753 (Myrtaceae)

Thu, 10 Jul 2025 00:00:00 GMT

Título: Eficiência de fungos entomopatogênicos no controle de moscas das-frutas (Diptera: Tephritidae) e gorgulho-da-goiaba (Coleoptera: Curculionidae) em plantio comercial de goiabeira Psidium guajava L. 1753 (Myrtaceae) Autor(es): Oliveira, Inessa Steffany Torres de Primeiro Orientador: Loureiro, Elisângela de Souza Abstract: Fruit flies (Diptera: Tephritoidea) and the guava weevil Conotrachelus psidii (Coleoptera: Curculionidae) are considered the main pests of Psidium guajava fruits. Faced with increasing restrictions on the use of chemical products, due to toxicity to human health and insect resistance to insecticides, the search for sustainable alternatives for pest control has intensified. It is emphasized that the control of insect pests in guava cultivation is essential for its economic viability. In this context, the objective of this research was to evaluate, in a commercial guava plantation, the action of two registered bioinsecticides Metarril®, active ingredient Metarhizium anisopliae, and Boveril®, active ingredient Beauveria bassiana), in the control of emergent of Anastrepha species (Diptera: Tephritidae) and Conotrachelus psidii (Coleoptera: Curculionidae) in soil sprayed with the fungi entomopathogenic. The two experiments were conducted in a commercial guava tree orchard, located in the district of Santa Terezinha, Itaporã, Mato Grosso do Sul, Brazil. To facilitate pest species contact with the fungi, each inoculum was incorporated into water containing a compatible adjuvant and sprayed onto the soil surface every seven days. The experimental design was a complete randomized block with 7 treatments and 4 replications, totaling 28 plots. Each plot was represented by a single plant. The treatments used were: Control (T), Metarril® with 1 application (Ma 1), Boveril® with 1 application (Bb 1), Metarril® with 2 applications (Ma 2), Boveril® with 2 applications (Bb 2), Metarril® with 3 applications (Ma 3), and Boveril® with 3 applications (Bb 3). The fungi were applied to the soil as a suspension, with varying numbers of applications, and the emergence of adults was monitored in cages. Newly emerged fruit fly and guava weevil adults were collected and transported to the Frugivorous Insects Laboratory at the Universidade Federal da Grande Dourados. Mortality data were subjected to Bayesian analysis (using Jamovi, Jasp, and R software). Control efficiency was calculated using Abbott's formula. For fruit flies: Both fungi were efficient, causing mortality of fruit flies. Metarhizium anisopliae demonstrated superiority in mortality over the control (BF₁₀ = 6.63), and B. bassiana also showed higher mortality (BF₁₀ = 1.65). Three applications showed strong evidence of superiority compared to no application (BF₁₀ = 6.19). However, comparisons between 1, 2, and 3 applications did not reveal statistically strong differences in mortality (BF₁₀ < 1). The highest control efficiency for M. anisopliae was 53.9% with 1 application. For B. bassiana, the highest efficiency was 50.6%, achieved with 2 and 3 applications. The efficiency of the fungi was lower in 2021 compared to 2022. For the guava weevil, both fungi were more effective than the control. B. bassiana stood out with very strong evidence of superiority over the control (BF₁₀ = 33.69). M. anisopliae was also effective, but with weaker evidence over the control (BF₁₀ = 1.59). Bayesian evidence for a substantial difference between the fungi was anecdotal (BF₁₀ = 1.31 for B. bassiana vs. M. anisopliae), indicating that both are viable, with B. bassiana numerically superior. There was no strong statistical evidence of difference in efficacy between 1, 2, or 3 applications among themselves (BF₁₀ < 1). The comparison between the control and 3 applications showed the strongest evidence (BF₁₀ = 3.86). In terms of efficiency, 2 and 3 applications of B. bassiana provided the highest efficiency (73.3%). M. anisopliae achieved its highest efficiency (58.6%) with only one application. Both fungi, M. anisopliae and B. bassiana, demonstrated potential to control both the species of fruit flies and the guava weevil, with adult mortality being influenced by the type of fungus and by the number of applications. Soil-based control with entomopathogenic fungi of these newly emerged pests species is viable in the field, constituting a tool for Integrated Pest Management (IPM) in fruit growing. Editor: Universidade Federal da Grande Dourados Tipo: Tese

Desenvolvimento biológico de Lasioderma serricorne (Coleoptera: Anobiidae) em substratos de armazenamento submetido a diferentes condições térmicas

Tue, 26 Aug 2025 00:00:00 GMT

Título: Desenvolvimento biológico de Lasioderma serricorne (Coleoptera: Anobiidae) em substratos de armazenamento submetido a diferentes condições térmicas Autor(es): Oliveira, Gisele Silva de Primeiro Orientador: Fernandes, Marcos Gino Abstract: Grain storage is a highly important stage in the agricultural production chain, constantly challenged by infestations of insect pests that result in significant economic and sanitary losses. Lasioderma serricorne (Fabricius, 1792) (Coleoptera: Anobiidae), commonly known as the cigarette beetle, stands out as a cosmopolitan pest of high economic importance due to its broad ecological plasticity and polyphagous feeding behavior. The traditional management of this species has relied on phosphine fumigation; however, repeated and improper use has led to the emergence of resistant populations, limiting its effectiveness and highlighting the need for alternative strategies. Among these alternatives, thermal control arises as a promising option, though the use of extreme temperatures presents both technical and economic limitations. Despite advances in understanding the biology of L. serricorne, little is still known about the combined physicochemical effects of economically significant food substrates and moderate temperatures on its biological development. The objective of this study was to evaluate the combined effects of different food substrates (flours and whole grains) and moderate thermal conditions (15 °C, 20 °C, and 30 °C) on the biological development of L. serricorne, in order to provide technical support for sustainable strategies of integrated pest management in storage environments. The experiments were conducted under laboratory conditions in a completely randomized design with a 4×3 factorial arrangement (four substrates × three temperatures) and three replications per treatment. For each experimental unit, 100 g of the respective substrate were placed in 300 mL plastic containers, maintained at the three specific temperatures under a relative humidity of 70 ± 2% and a 12-hour photoperiod. Each container was infested with 100 four-day-old adults of L. serricorne, kept closed for 15 days to allow oviposition. After this period, adults were removed, and daily evaluations were carried out until larval viability was detected; pupal development, adult emergence, and longevity were then assessed every other day. For longevity tests, five emerged adults were individualized in Eppendorf tubes without substrate and monitored until death. Data were subjected to ANOVA, and means were compared using Tukey’s test (p ≤ 0.05). The results showed that temperatures of 15 °C and 20 °C were effective in controlling the pest, whereas 30 °C significantly favored insect development. Rice and corn flours yielded the highest number of hatched larvae (6.02 ± 96.37 and 5.66 ± 95.85, respectively), pupal development (30.06 ± 0.54 and 15.00 ± 2.89), and adult emergence (4.84 ± 0.73 and 13.67 ± 3.48) at 30 °C across all assessments. Soy flour exhibited the lowest larval viability (2.82 ± 15.85) and no pupal development or adult emergence at any tested temperature. Whole grains showed drastically reduced development compared to their corresponding flours, with maximum larval viability values of only 0.36 ± 0.58 for soybean grain at 30 °C. Adult longevity was highest in rice and wheat flours (18 days) at 30 °C, whereas in corn grain at 20 °C, it reached 48 ± 12 days. These findings suggest that grain physical integrity and the choice of less favorable substrates are complementary strategies for integrated management of L. serricorne. Thus, maintaining grain integrity represents an accessible control measure when combined with temperature management. Flours, particularly rice flour, pose a significantly higher infestation risk than the original grains, as milling transforms a resistant product into a highly susceptible one. Soybeans and soybean flour proved to be resistant substrates, offering a low-risk storage option. Temperature control must be applied cautiously, since moderate temperatures (20 °C) may extend adult longevity. For small producers and units with limited infrastructure, preventive and low-cost measures such as maintaining grain integrity and avoiding the joint storage of grains and flours are recommended, representing an effective approach to reduce post-harvest losses and strengthen food security. Editor: Universidade Federal da Grande Dourados Tipo: Dissertação