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Brazilian forest producers have developed integrated management programs to increase the effectiveness of the control of leaf-cutting ants of the genera Atta and Acromyrmex. These measures reduced the costs and quantity of insecticides used in the plantations. Such integrated management programs are based on monitoring the ant nests, as well as the need and timing of the control methods. Chemical control employing baits is the most commonly used method, however, biological, mechanical and cultural control methods, besides plant resistance, can reduce the quantity of chemicals applied in the plantations.

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The reproductive potential and longevity of Podisus nigrispinus (Dallas) were determined under laboratory conditions at a constant temperature of 25°C. The data were used to calculate life‐fertility tables and rates of increase. The fecundity plateau of P. nigrispinus lasted 18 days, and during this period mean fecundity was 8.89 eggs per female per day. It started at the eighth day of age and ended at the 18th day of age. The declining fecundity period started at 18 days of age and ended with the death of the females. The female of P. nigrispinus oviposited a mean of 188.54 eggs, and had a mean longevity of 31.21 days. The gross reproductive rate (GRR) was 104.374 females/female; the net reproductive rate (Ro) was 31.945 females/female; the generation time was 47.390 days; the doubling time was 9.480 days; the intrinsic rate of increase (rm) was 0.073, and the finite rate of increase (λ) was 1.076. The predator population increased by 16.61 adult progeny per female per generation in the laboratory.

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Este trabalho objetivou determinar o método de correção de estande mais adequado aos dados de produtividade na cultura do milho, na avaliação de 33 cultivares, em oito ambientes. Os métodos avaliados foram: sem correção, regra de três, método de Zuber, covariância de estande médio, covariância de estande ideal, o método proposto por Cruz, o método proposto por Vencovsky & Cruz, e o proposto neste trabalho, de correção estratificada com base no agrupamento de cultivares, para a característica estande, pelo teste de Scott & Knott. O método proposto neste trabalho, o de covariância de estande ideal e o de Vencovsky & Cruz foram mais adequados para essa correção, pois apresentaram baixos valores de coeficiente de variação e altos valores de F, confirmados pelos baixos valores de Pi e Pi multivariado na análise conjunta. Os métodos de regra de três e o proposto por Cruz apresentaram as maiores médias de produção, o que superestima o valor real da produção média. O método proposto neste trabalho foi eficiente em corrigir as cultivares, uma vez que as cultivares mais produtivas foram também as de maior potencial em deixar descendentes, medido pelo estande médio.

Development of Thyrinteina arnobia Stoll (Lepidoptera: Geometridae) on leaves of Eucalyptus urophylla and Psidium guajava ABSTRACT -The development of Thyrinteina arnobia Stoll (Lepidoptera: Geometridae) caterpillars fed either on Eucalyptus urophylla or Psidium guajava (Myrtaceae) leaves was studied in laboratory. The first instar was the most critical for survival of this insect in both diets. Shortest larval period (27 days) was obtained for males on guava leaves, with the longest one for caterpillars which originated females or males with E. urophylla leaves (37 days). No insects feeding on guava leaves which originated males reached six instar while the sexual ratio with this diet was 0.6. With E. urophylla leaves, 58.3% of males presented six instars with a sexual ratio of 0.3. The width of head capsules of the caterpillars, for both sexes, was significantly different in both diets, being bigger for those fed with guava leaves, with rates of 4.3; 6.2; 10.0 and 13.0%, from the second to the fifth instar, respectively. This rate reached 28.0% in the sixth instar, corresponding to an increase of 113.0% in relation to the previous instar, indicating that individuals fed on guava leaves are stronger and more vigorous than those fed on E. urophylla. Largest width of the head capsule was associated to high viability and short duration of the larval period for individuals fed on guava leaves what suggests that this diet is more suitable for rearing this insect. T. arnobia is a native pest of guava and probably it is not adapted to feed on Eucalyptus yet.