Infestation level of fruit flies in the boundary zone in Rio Grande do Sul, BrazilFruit flies are considered the major pests of fruit worldwide. Tefritids and lonchaeids are major pests in this group of insects. However, little information exists regarding the potential for harm of lonchaeids. The aim of this study was to identify the infestation levels of fruit flies in the boundary zone of Rio Grande do Sul with Argentina and Uruguay. The study was conducted in 2011 and 2012 in Itaqui, Quaraí, Santana do Livramento and Uruguaiana, RS. Fruits were collected from19 exotic and native plant species, and the infestation levels in pupae/kg of fruit and pupae/ fruit were calculated. The highest rate of Ceratitis capitata infestation occurred in nectarine, with 72.01 pupae/kg and 2.51 pupae/fruit. Anastrepha fraterculus showed high levels in cherry, corresponding to 57.57 pupae/kg and 0.23 pupae/fruit. Lonchaeids were represented by Neosilba and Lonchaea, infesting papaya and star fruits, respectively. In the studied municipalities of Rio Grande do Sul, the following species of fruit flies occurred: C. capitata, A. fraterculus, Neosilba zadolicha and Lonchaea sp.

The Brazil’s economy is supported by agribusiness, however, the continuous cycle of food production and favorable climate contributes to the incidence of pest insects all year round. The fall armyworm Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) is considered the main insect in the corn crop, due to voracity of the caterpillars and occurrence throughout the crop cycle. Therefore, the chemical control has been demanded considerably, causing emergence of populations resistant to the different products, as well as implications in the environment. Thus, studies are needed to evaluate the efficiency of chemical insecticide control according to the susceptibility and the stages of biological development of the pest. The objective of this work was to evaluate the performance of isolated and combined insecticides for the control of S. frugiperda caterpillars under laboratory conditions. In the residual and direct contact bioassays, 8 treatments with 5 replications were used in a completely randomized design, performed with 2nd and 5th instar. The results showed that by residual contact after 72 hours, clofenapir + zeta-cypermethrin treatment had 100% efficacy in the mortality of both instars. When applied via direct contact 72 hours later, the combined treatments showed an efficiency above 80%. However, for an integrated pest management program, where it was recommended the association of different control tactics, the management of insecticides with clofenapir + zeta-cypermethrin was effective with 100% control efficiency in both instars.

Helicoverpa armigera (Hübner, 1805) and Spodoptera frugiperda (Smith, 1797) are polyphagous pests of great agricultural importance in subtropical and temperate climate regions. The usual management of production areas in the southern region of Brazil occurs after the harvesting of summer crops, and the areas are sown with pasture. Thus, forages recommended for grazing are azevém (Lolium multiflorum Lam.) and cornichão (Lotus corniculatus L.) due to their nutritional benefits, good palatability, regrowth, and hardiness. Considering the high degree of polyphagia of H. armigera and S. frugiperda, and the impact of maintaining continuous feeding areas (green bridges) in the management of these species, this work aimed to evaluate the development of H. armigera and S. frugiperda fed leaves of azevém and cornichão under laboratory conditions. The insects were collected in the city of Capão do Leão/RS in corn and soybean plantations. For each forage species, 130 newly hatched caterpillars were each placed in autoclaved glass tubes, with one-third of the tube length containing forage. The tubes were capped with waterproof cotton and placed in a climate-controlled room at 25 ± 1°C, 70 ± 10% relative humidity, and a 12-h photophase. The food was replenished daily until the caterpillars entered the pupae stage. The pupae were sexed and weighed, and the newly emerged adults were placed in pairs in PVC cages, lined with white A4 sulfite paper. The papers used as a laying substrate were removed and changed daily, and eggs were counted. The number of instars was determined by the linearized Dyar rule model. The complete randomization design was employed for the variables biological cycle length and viability of egg, caterpillar, pre-pupa, pupa, adult, and pre-oviposition phases and weight of caterpillars on the 14th day and pupae after 24 h. Based on the results obtained, a fertility life table was prepared. H. armigera did not complete the cycle, with only three instars and a duration of 22.1 and 24.6 days in azevém and cornichão, respectively. When evaluated in S. frugiperda caterpillars, development in forage species was observed, with five and six instars and duration of 51.7 and 45.1 days in azevém and cornichão, respectively. The azevém was distinguished by interference in the development cycle of the species, reducing the effect of the green bridge. In addition, surviving insects were susceptible to the effects of the agroecosystem due to the low-quality food source.

Brazil, in lowland environment, corn has the potential for crop rotation with irrigated rice to minimizing infestations of red rice. The use of resistant cultivars associated to the use of insecticides are the main methods of control of the fall armyworm, Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae). However, there are lack of field studies that assess the crop’s production chain. The objective of this study was to evaluate the performance of corn cultivar, the conventional AG 9045 and the isogenic AG 9045 PRO2 Bt on the control of S. frugiperda, as well as to analyze the cost of production in the lowland environment. The cultivars were sown in the 2014/2015 and 2015/2016 harvests with adopted spacing of 0.7 meters and length of 5 meters. The application of insecticides was performed when the index of 10% of plants attacked by S. frugiperda was reached. Percentage (%) of attacked plants, corn productivity (kg ha-1) and cost of production (US$ ha-1) were evaluated. In the final analysis, the AG 9045 PRO2 isogenic Bt in conjunction to the chlorfenapyr + zeta-cypermethrin treatment show better efficiency on the control of S. frugiperda caterpillars, by a combination of two different control methods and active principles in the control of S. frugiperda, higher productivity indexes (3,155.58 kg ha-1) and profitability (-112.08 US$ ha-1).

The soybean is the main agricultural product produced in Brazil. Among the States, Rio Grande do Sul was the third largest producer in the 2017/2018 harvest. However, insects interfere on the productivity and provide an increase in the cost of production. The velvetbean caterpillar, Anticarsia gemmatalis (Hübner, 1818) (Lepidoptera: Eribidae) is considered one of the main leaf stripper caterpillars. The occurrence can completely fade, reflected in the grain yield. The chemical method is the main control adopted, however, due to the inadequate management of the crop, failures are observed frequently on the field. In this context, the insecticide management is considered an alternative, still little adopted, due to a lack of knowledge between the movement action and the susceptibility of the insect. Therefore, the objective was to evaluate the performance of insecticides used in the soybean crop for the control of A. gemmatalis under laboratory conditions. In the residual and direct contact bioassays, eight treatments with five replicates were used in a completely randomized design, with 2nd and 5th instar caterpillars of A. gemmatalis. The results showed that by residual contact during 24 hours, all the treatments with exception of the control had effectiveness in both instar mortality. The treatments flubendiamide + zeta-cypermethrin and zeta-cypermethrin after four hours application reached 100% of effectiveness. Thus, aiming an integrated pest management program, where it advocated the association of different control tactics, the insecticide management with flubendiamide + zeta-cypermethrin were effective with 100% of control efficiency in both instars.

Soybean crop represents a large economic share in the Brazilian agricultural production. In Rio Grande do Sul (RS), with each new crop cycle there is an increase in the area under cultivation. In the lowland environment, the crop covers 5.4 million hectares, corresponding to about 20% of the State total area. Using transgenic cultivars whose main advantage is controlling target insects, as well as the reduced number of insecticide applications throughout the crop can be a viable alternative. However, the high cost of transgenic seed is considered as the main disadvantage in adopting this technology. The objective of this study was to evaluate the performance of cultivars RR1 and RR2 in relation to the occurrence of caterpillars and stink bugs, as well as to evaluate the production cost. The experiment was set up at Embrapa Clima Temperado in the crop seasons of 2014/2015 and 2015/2016, with conventional cultivars (BMX Potência (RR1 6.7)) and Bt isolines (BMX Ponta (IPRO 6.6)) and BMX Vanguarda (IPRO 6.0)). BMX Potência cultivar showed a higher incidence of defoliating caterpillars and Nezara viridula stinkbug, but it is the most indicated cultivar, among those evaluated, for the south lowland environment of RS, due to its yield and profitability.

Objetivou-se com esse trabalho, abordar a educação ambiental no ensino médio, estimulando a preservação, conscientização e busca pelo conhecimento, através da problematização de temáticas ambientais locais. Realizou-se um Painel com a temática: “Impacto da agropecuária no meio ambiente em Itaqui - RS”, em que foram proferidas palestras técnicas e educativas para alunos do ensino médio, em três escolas estaduais do município de Itaqui/RS, abordando os seguintes temas: “arenização”, “impacto do uso de agrotóxicos na lavoura arrozeira”, “casca de arroz” e “desperdício de alimentos”. Os resultados obtidos mostraram que 34 a 56% dos entrevistados não conheciam os assuntos e 95 a 100% afirmaram que a comunidade deveria ter conhecimento sobre os temas, por serem os principais problemas ambientais da região. Os alunos participaram com questionamentos referentes aos temas abordados durante e após as apresentações, obtendo conhecimento mais amplo sobre conservação e preservação do meio ambiente e sobre a realidade do município.