Soil-plant-gall relationships: from gall development to ecological patterns.

The adaptive nature of the galler habit has been tentatively explained by the nutrition, microenvironment, and enemy hypotheses. Soil attributes have direct relationships with these three hypotheses at the cellular and macroecological scales, but their influence has been restricted previously to effects on the nutritional status of the host plant on gall richness and abundance. Herein, we discuss the ionome patterns within gall tissues and their significance for gall development, physiology, structure, and for the nutrition of the gallers. Previous ecological and chemical quantification focused extensively on nitrogen and carbon contents, evoking the carbon-nutrient defence hypothesis as an explanation for establishing the plant-gall interaction. Different elements are involved in cell wall composition dynamics, antioxidant activity, and regulation of plant-gall water dynamics. An overview of the different soil-plant-gall relationships highlights the complexity of the nutritional requirements of gallers, which are strongly influenced by environmental soil traits. Soil and plant chemical profiles interact to determine the outcome of plant-herbivore interactions and need to be addressed by considering not only the soil features and galler nutrition but also the host plant's physiological traits. The quantitative and qualitative results for iron metabolism in gall tissues, as well as the roles of iron as an essential element in the physiology and reproduction of gallers suggest that it may represent a key nutritional resource, aligning with the nutrition hypothesis, and providing an integrative explanation for higher gall diversity in iron-rich soils.

Larval Rearing and Nutrition of the Polyphagous Tephritid Pest Anastrepha ludens on Artificial Diets with Calcium Alginate, Agar, or Carrageenan as Gelling Agents at Various Concentrations and across Extreme Larval Density Conditions.

Research on larval rearing and nutrition of tephritid flies on artificial diets is key for the sterile insect technique. Here, we examined the effects of the type of gel (calcium alginate, agar, or carrageenan), at varying percentages in artificial diets for the polyphagous pest Anastrepha ludens, on the physicochemical and nutritional traits of the diets, and the effects of the type of gel, the gel content and the larval density (larvae/g of diet) used in production, quality parameters for mass-reared tephritids, diet removal (an indirect estimation of diet consumption), and nutritional traits of flies. Regardless of the gel content, calcium alginate diets were firmer and more resistant to penetration than the agar and carrageenan diets. The larval recovery, pupation, pupal weight, and flight ability of A. ludens were lower in calcium alginate diets than in agar and carrageenan diets. Diet removal was higher in calcium alginate diets; however, low levels of ammonium and high levels of uric acid in excretions from larvae on these diets suggest an alteration in protein metabolism. The firmness and penetration resistance characteristics of calcium alginate diets may have limited movement and feeding of larvae, but this could be overcome by the collective feeding of large groups of larvae. Our findings provide insights into the mechanism governing gel-diet rearing systems for A. ludens.

A soybean trypsin inhibitor reduces the resistance to transgenic maize in a population of Spodoptera frugiperda (Lepidoptera: Noctuidae).

Lepidopteran pests have been successfully managed by the adoption of insect resistant transgenic plants expressing Cry and/or Vip insecticidal proteins derived from Bacillus thuringiensis (Bt plants). Among such pests, Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) is highlighted for its destructive potential in maize crops and for cases of field-evolved resistance to Bt plants. Cry insecticidal proteins expressed in Bt plants are known for their interaction with insect midgut receptors and subsequent midgut cell disruption that leads to target pest death. In the midgut of lepidopteran larval pests such as S. frugiperda, serine proteases are important in dietary protein digestion and activation or degradation of insecticidal proteins. This work was conducted to evaluate if the use of a soybean trypsin inhibitor (SBTI) could disrupt the development of a Bt-susceptible and a Bt-resistant population of S. frugiperda ingesting Bt (expressing Cry1F, Cry1A.105, and Cry2Ab2 Cry proteins) and non-Bt maize plants. The SBTI was produced and purified using recombinant expression in E. coli followed by purification in Ni-Sepharose. Bioassays using non-Bt maize leaves indicated that the development of susceptible and resistant populations of S. frugiperda was not influenced by the ingestion of SBTI. However, when the resistant population consumed Bt maize plants amended with SBTI, high mortality along with a reduction in larval weight and reduced activity of digestive trypsins were observed. Although the mode of action was not elucidated, it is possible that the consumption of SBTI increased susceptibility to Bt maize in the resistant population of S. frugiperda.

Optimization of Methodology for Rearing Spodoptera albula on Artificial Diet.

Advances in techniques for rearing insects on artificial diets are fundamental to solving issues of basic and applied entomology. In this study, we evaluated the development of Spodoptera albula (Walker) (Lepidoptera: Noctuidae) on three artificial diets used for other species of Lepidoptera, at three larval densities, and two densities of adult couples housed in oviposition cages of two sizes, with the aim of optimizing methodology for rearing S. albula in the laboratory. Biological parameters were recorded from S. albula, and a fitness index was calculated based on the larval survival and duration and weight of pupae. The total and daily oviposition was recorded using 5 or 10 adult couples of S. albula housed in two cage sizes. Concentrations of total nitrogen and protein in the tested diets were determined. Development of S. albula was completed in all artificial diets; however, the diet used for rearing Anticarsia gemmatalis (Hübner) larvae was the most suitable for S. albula, yielding intermediate development time and higher survival relative to the other diets. Individualization of larvae favored S. albula development by producing overall greater weights of larvae and pupae, higher survival rates, and longer adult longevity. Cage size and number of couples per cage did not influence S. albula fecundity in the experiment conditions. Spodoptera albula can be satisfactorily reared on the artificial diet used for A. gemmatalis, using one larva per tube, and either density of adults at any cage size. Additional amendments are needed in the rearing methodology to achieve optimal conditions for larval development to adulthood.

A dieta alimentar da presa Tenebrio molitor (Coleoptera: Tenebrionidae) pode afetar o desenvolvimento do predador Podisus nigrispinus (Heteroptera: Pentatomidae)? / Can the diet of the prey Tenebrio molitor (Coleoptera: Tenebrionidae) affect the development of the predator Podisus nigrispinus (Heteroptera: Pentatomidae)?

Inimigos naturais são importantes para o controle de pragas em culturas agrícolas e florestais. A criação de insetos predadores em biofábricas deve ser de baixo custo para serem utilizados em programas de Manejo Integrado de Pragas (MIP). O objetivo deste trabalho foi avaliar o desenvolvimento de Podisus nigrispinus Dallas, 1851 (Heteroptera: Pentatomidae), alimentado com larvas de Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae), criadas com as seguintes dietas: farelo de trigo, ração triturada ou peletizada para aves poedeiras e fubá de milho. Foram obtidos os parâmetros de desenvolvimento e reprodução necessários para calcular a tabela de vida do predador. Os parâmetros da tabela de vida revelaram crescimento populacional em todos os tratamentos. No entanto, a taxa líquida de reprodução (Ro) de P. nigrispinus foi menor quando alimentados com larvas de T. molitor criadas com fubá de milho, mostrando ser a alimentação menos adequada para esse predador. Por proporcionar maior número total de ovos, o farelo de trigo constituiu a melhor dieta para P. nigrispinus. Estudos sobre dietas de presas alternativas são importantes, pois podem favorecer a nutrição de inimigos naturais e, consequentemente, melhorar o desempenho das criações massais em laboratório.(AU)

Natural enemies are important for controlling pests in agricultural and forestry culture. The reproductions of predatory insects in biofactories should have low cost to be used in Integrated Pest Management Program (IPM). The objective of this study was to evaluate the development of Podisus nigrispinus Dallas, 1851 (Heteroptera: Pentatomidae) fed with Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae). The larvae of T. molitor were created with the following diets: wheat bran, shredded or pelleted poultry feed layers and corn meal. Parameters for the development and reproduction of the P. nigrispinus were obtained. Parameters of the life table show population growth in all treatments. However, the net rate of reproduction (Ro) of P. nigrispinus was lower when they were fed with larvae of T. molitor created with corn meal, which proved to be the least adequate food for this predator. By providing a larger total number of eggs, wheat bran was the best diet for P. nigrispinus. Studies on alternative prey diets are important as they may favor the nutrition of natural enemies and, consequently, improve the performance in laboratory rearing.(AU)

A dieta alimentar da presa Tenebrio molitor (Coleoptera: Tenebrionidae) pode afetar o desenvolvimento do predador Podisus nigrispinus (Heteroptera: Pentatomidae)? / Can the diet of the prey Tenebrio molitor (Coleoptera: Tenebrionidae) affect the development of the predator Podisus nigrispinus (Heteroptera: Pentatomidae)?

Inimigos naturais são importantes para o controle de pragas em culturas agrícolas e florestais. A criação de insetos predadores em biofábricas deve ser de baixo custo para serem utilizados em programas de Manejo Integrado de Pragas (MIP). O objetivo deste trabalho foi avaliar o desenvolvimento de Podisus nigrispinus Dallas, 1851 (Heteroptera: Pentatomidae), alimentado com larvas de Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae), criadas com as seguintes dietas: farelo de trigo, ração triturada ou peletizada para aves poedeiras e fubá de milho. Foram obtidos os parâmetros de desenvolvimento e reprodução necessários para calcular a tabela de vida do predador. Os parâmetros da tabela de vida revelaram crescimento populacional em todos os tratamentos. No entanto, a taxa líquida de reprodução (Ro) de P. nigrispinus foi menor quando alimentados com larvas de T. molitor criadas com fubá de milho, mostrando ser a alimentação menos adequada para esse predador. Por proporcionar maior número total de ovos, o farelo de trigo constituiu a melhor dieta para P. nigrispinus. Estudos sobre dietas de presas alternativas são importantes, pois podem favorecer a nutrição de inimigos naturais e, consequentemente, melhorar o desempenho das criações massais em laboratório.(AU)

Natural enemies are important for controlling pests in agricultural and forestry culture. The reproductions of predatory insects in biofactories should have low cost to be used in Integrated Pest Management Program (IPM). The objective of this study was to evaluate the development of Podisus nigrispinus Dallas, 1851 (Heteroptera: Pentatomidae) fed with Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae). The larvae of T. molitor were created with the following diets: wheat bran, shredded or pelleted poultry feed layers and corn meal. Parameters for the development and reproduction of the P. nigrispinus were obtained. Parameters of the life table show population growth in all treatments. However, the net rate of reproduction (Ro) of P. nigrispinus was lower when they were fed with larvae of T. molitor created with corn meal, which proved to be the least adequate food for this predator. By providing a larger total number of eggs, wheat bran was the best diet for P. nigrispinus. Studies on alternative prey diets are important as they may favor the nutrition of natural enemies and, consequently, improve the performance in laboratory rearing.(AU)

New protein sources in adults diet for mass-rearing of Anastrepha fraterculus (Diptera:Tephritidae)

The aim of this study was to find alternatives to reduce the cost of mass production of the South American fruit fly (A. fraterculus) by looking for locally available products as protein source in the diet of adults to replace the imported product without changing the quality parameters. Two yeast from a Brazilian company were evaluated. The quality parameters showed that the imported hydrolyzed yeast used in the adult diet could be perfectly replaced by the local products tested, with a reduction of over 80% of the cost of the diet. The quality of the produced insects remained the same and there were improvements in some quality parameters such as the volume of eggs produced, number of adults flying and longevity under the stress.

Sexually differentiated flight responses of the Mexican bean beetle to larval and adult nutrition.

Flight of male and female Mexican bean beetle adults was examined in laboratory tests. The experimental design made it possible to examine flight behavior not only with respect to different types of hosts (young vs senescent common bean foliage) but also with respect to effects due to their utilization during particular stages of beetle development. The median flight time of males was significantly affected by the adult host, but not by the juvenile host; whereas, the median flight time of females tended to be more affected by the juvenile than by the adult host. These different effects of hosts on the flight times of males and females resulted in sexual dimorphism in flight when the sexes were fed senescent foliage as adults. Although age significantly affected the flight time of both males and females, the reproductive status of females did not affect their flight times. The significance of these results are discussed with respect to the influence of the nutritional complexity of habitats on life history strategies and population dynamics.