A B S T R A C TBean weevil and maize weevil can cause considerable damage to stored grains. These insects are mainly controlled with synthetic chemical insecticides, which may bring serious problems to human and environmental health. Therefore, this study aimed to evaluate the efficiency of the essential oil of clove [Syzygium aromaticum (L.) Merrill & Perry (Myrtaceae) (origin: Bahia, season Sep.2014-Feb.2015] in the control of S. zeamais and A. obtectus under laboratory conditions. The essential oil was extracted through the classic hydrodistillation process and its chemical components were identified via gas chromatography. Oil efficiency was tested at the doses of 35, 17.9, 8.9, 3.6, 1.8, 0.4 and 0.2 µL g -1 (derived from a pilot study) for insect control and the LC 50 was determined. The results showed that eugenol was the major compound. The essential oil caused mortality of 100% for both species 48 h after treatment with the concentrations of 17.9 and 35 µL g Atividade inseticida do óleo essencial de cravo-da-índia sobre o caruncho-do-feijão e o gorgulho-do-milho R E S U M OO caruncho-do-feijão e o gorgulho do milho podem causar grandes prejuízos aos grãos armazenados. Entre as alternativas de controle está a utilização de óleos essenciais de plantas com propriedades inseticidas; objetivou-se, assim, avaliar a eficiência do óleo essencial de cravo-da-índia no controle de S. zeamais e A. obtectus em condições de laboratório. O óleo essencial foi extraído por processo clássico de hidrodestilação e seus constituintes químicos foram identificados por cromatografia gasosa. A eficiência deste óleo foi testada nas doses 35; 17,9; 8,9; 3,6; 1,8; 0,4 . A CL 50 para A. obtectus foi 9,45 µL g -1 contra 10,15 µL g -1 do S. zeamais. A utilização do óleo essencial de cravo-da-índia representa uma alternativa promissora a ser usada em condições de armazenagem para o manejo integrado de pragas de grãos armazenados.

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Temperature is a determining factor for the development and establishment potential of insect pests. The present study describes the impact of temperature (13, 18, 23, 25, 28, 30, and 33 °C) on the life cycle parameters and phenotypic plasticity of South American populations of Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) in the laboratory. Secondary objectives were to determine the lower thermal threshold and thermal constant to estimate the number of annual generations of the insect in small‐fruit‐producing regions in Brazil. The highest egg‐to‐adult survival was recorded at 23 and 25 °C. At 30 and 33 °C, no emergence of D. suzukii was observed. The egg‐to‐adult development time was shortest at 25 and 28 °C (ca. 10 days). The net reproductive rate (R0), and the intrinsic rate of population increase (rm) were highest at 23 and 25 °C. In contrast, temperatures of 13 and 28 °C generated largest and smallest body sizes, respectively, and caused reductions of 99 and 93% in R0. The estimated lower thermal threshold was 7.8 °C for egg‐to‐adult survival. The estimated thermal constant was 185.8 degree days, and the estimated annual number of generations of D. suzukii ranged from 17.1 in cold regions to 27.2 in warm regions. The results of the present study are important for understanding D. suzukii occurrence in the field, contributing to more informed and precise pest management.

Corn weevil (Sitophilus zeamais) may cause great losses in the crop and in stored corn grains. This insect is controlled with the use of chemical insecticides, which may cause serious damage to human health. One alternative of control is the use of inert dusts. The objective of this study was to evaluate the efficiency of inert dusts in the control of S. zeamais under laboratory conditions. The experiment was conducted in 2014, in a completely randomized design, and the treatments consisted of basalt dust with three different granulometries (A, B and C) and diatomaceous earth, each of which at the doses of 2 and 4 kg t-1 and a control (no application). Each treatment had four replicates, and the sample unit consisted of 20 g of corn grains infected with 10 adults of S. zeamais kept in temperature-controlled chamber at 25 °C, 70% RH and photophase of 12 h. The dust efficiency was calculated using the equation of Abbott. The mortality rate was higher with the use of diatomaceous earth, reaching 100% after 5 days of exposure and the percentage of control for basalt dusts, 29 days after treatment, was above 80%.

RESUMOO presente estudo teve como objetivo testar a eficiência do extrato supercrítico de Melia azedarach no controle de Sitophilus zeamais por meio do contato tarsal. Observou-se a sobrevivência dos insetos a cada 24 h após o início do experimento. Constatou-se que houve maior mortalidade de insetos nas primeiras 72 h. O tratamento que teve melhor desempenho considerando-se a relação tempo de ação e número de insetos mortos foi o de concentração 200 μL mL -1 . A concentração letal média que mata 50% da população (CL50) obtida após 96 h do tratamento foi de 165,52 μL mL -1 , indicando que a maior dose pode ser reduzida com resultados satisfatórios para as condições empregadas no estudo. O extrato de M. azedarach revelou-se efetivo no controle de S. zeamais em condições de laboratório. ABSTRACTThis study aimed to test the efficiency of the Melia azedarach supercritical extract in controlling Sitophilus zeamais through tarsal contact. The survival of insects was observed every 24 h after the experiment started. A higher mortality of insects was found during the first 72 h. The treatment that had the best performance considering the action time and the number of dead insects was that at 200 μL mL-1 concentration. The mean lethal concentration that kills 50% of the population (LC50) obtained after 96 h treatment was 165.52 µL ml-1, showing that the higher dose can be reduced with satisfactory results for the conditions used in this study. The extract of M. azedarach was effective in controlling S. zeamais under laboratory conditions.

Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) is a major fruit pest, which is basicaly controlled using insecticides, which represents a risk to benefi cial arthropods, human health and food contamination. The sterile insect technique (SIT) is a potential alternative tool for the management of this pest, however, only confl icting data is found regarding the optimal dose to achieve sterility. Thus, this study evaluated the effect of gamma radiation doses (0, 40, 50, 60 and 70 Gy) on male and female reproductive sterility, gonads morphometry, emergence, fl ight ability, and longevity under nutritional stress of A. fraterculus. Full female sterility was achieved at 50 Gy, while full male sterility was achieved at 70 Gy. Both ovarian and testicular sizes were affected by irradiation, while no infl uence was observed on the quality parameters evaluated. Our results suggest that 70 Gy applied 48 h before adult emergence can be used to sterilize A. fraterculus in a SIT programme.

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