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Jatropha curcas L. has been studied with the aim of attending the bioenergy demand in Brazil. In this study, the time of occurrence, the severity, and the control of powdery mildew and rust in a commercial crop were investigated. During the evaluation period, powdery mildew was first observed soon after the onset of the raining period in October. Rust was first observed in April. Metarhizium anisopliae. Azadirachta indica oil, J. curcas oil, and the fungicide triadimenol were efficient in controlling powdery mildew. None of these products nor potassium silicate did control rust. RESUMO Jatropha curcas L. tem sido estudada com o objetivo de atender a demanda por bioenergia no Brasil. Neste trabalho estudou-se a época de ocorrência, a severidade e o controle do oídio e da ferrugem numa lavoura comercial. Durante o período de avaliação, o oídio foi observado pela primeira vez logo após o início do período de chuvas em outubro. A ferrugem foi observada pela primeira vez em abril. Metarhizium anisopliae, óleo de Azadirachta indica, óleo de J. curcas e o fungicida triadimenol foram eficientes no controle do oídio. Nenhum desses produtos nem silicato de potássio controlaram a ferrugem.

Helicoverpa armigera (Hubner, 1805) (Lepidoptera: Noctuidae) is an insect pest that attacks several cultures and has been a cause of concern in Brazil. The objective of this study was to evaluate parasitism in pupae and caterpillars of H. armigera by Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae), in laboratory, as well as checking if T. howardi parasitoid has the ability to locate and infect H. armigera. In the laboratory, pupae of H. armigera and Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) were exposed to 15 T. howardi females for 24 hours. Third, fourth and fifth instars of H. armigera were exposed to three T. howardi females for 24 hours. In the field experiment, cages were installed. Ten caterpillars of the fifth instar of H. armigera were released in each cage and waited for the necessary period for them to soak in the soil. After this period, 150 T. howardi females were released in each of four cages and in one cage there was no release of parasitoids. In the laboratory, the percentage of parasitized and emergent pupae was 100% in both hosts. The life cycle of T. howardi in H. armigera pupae was 15 days, and for D. saccharalis it was 16 days. The progeny was significantly larger for the host H. armigera (689.00) compared to D. saccharalis (358.27). The sex ratio was 0.91 and 0.87 for H. armigera and D. saccharalis, respectively. The longevity of males (25.60 days) and females (26.95 days) in the treatment with H. armigera differed from the treatment with D. saccharalis, which was 21.70 days for males and 22.95 days for females. For the experiment with H. armigera caterpillars, it was found that only two caterpillars from the fifth instar were parasitized with emergence of parasitoids in the pupal phase, with a progeny of 81 individuals; egg-adult cycle was 19.5 days; sex ratio of 0.88; male longevity was 19.6 days and for females 20.3 days. Despite the high rate of parasitism of T. howardi in H. armigera pupae in the laboratory, the same did not occur for caterpillars. In the field evaluation, of the total of 50 caterpillars released in the cages, 34 pupae were collected. Of these, 31 pupae had emergence of the H. armigera moth. No parasitism by T. howardi was found in H. armigera pupae. Further studies should be conducted to evaluate T. howardi parasitism in H. armigera pupae under field conditions.

Managing Helicoverpa armigera is still a major challenge for Brazilian farmers, due to limited information available about chemicals and biological control of this pest in Brazil. This study focused on evaluating the biological aspects of Podisus nigrispinus fed with H. armigera, under laboratory conditions, as well as verifying the capacity of the P. nigrispinus in preying on caterpillars of H. armigera in the field, in soybean crops. The experiments were conducted in laboratory under controlled temperature conditions of 25±2 ºC, relative humidity (RH) 60±10% and 14-hour photophase, as well as in the field, at the experimental station of Fundação MS in Maracaju, MS. In the laboratory, second instar nymphs of P. nigrispinus were placed in plastic jars and fed with H. armigera larvae or Tenebrio molitor larvae throughout the nymphal phase. When they reach adulthood, 15 couples were formed, remaining with the same prey of the previous phase. For the field trial, soybean plants were caged, and inside these cages were released eight quarter-instar H. armigera caterpillars. Subsequently, in each cage were released an adult female or a fifth instar nymph, and after 24 hours, the number of prey caterpillars were assessed. Predator nymphal duration was shorter in treatment with H. armigera than with T. molitor. Nymphal viability was similar between treatments. Adult females and males fed with H. armigera presented greater body mass than those fed with T. molitor. The number of postures per female and the number of eggs per female were similar between treatments. The incubation period of eggs was longer for treatment with H. armigera, differing statistically from treatment with T. molitor. Eggs from treatment with H. armigera showed similar viability to treatment with T. molitor, not differing statistically. Females and males under treatment with H. armigera showed longer longevity compared to treatment with T. molitor. Adult females preyed on average 2.26 caterpillars within 24 hours and fifth instar nymphs preyed on 1.73 caterpillars/day. P. nigrispinus showed better development when fed with H. armigera, demonstrating that it can be used as an alternative host for breeding this predator. The predator showed satisfactory performance for predation rate/day. Release of fifth instar nymphs and adult females of P. nigrispinus may reduce the pest population in relation to the absence of the predator under field conditions, an important alternative to be used in H. armigera integrated management programs.

The aim of this study was to evaluate the non-preference for oviposition Vatiga illudens (Drake, 1922) (Hemiptera: Tingidae) in cassava cultivars. The following cultivars were compared: Kiriris, N-25, Fecula Branca, IAC 90, M Ecu 72 and IAC 576, preference tests for oviposition were conducted, with a choice test in semi-field conditions. An adult double V. illudens was released in the leaves of cassava of their cultivars. Allowed to feeding and oviposition of these insects for 72 hours. We evaluated the number of eggs / female / leaf, the number of droppings / couple / sheet and the preference index for oviposition. The cultivar M Ecu 72 demonstrated to be highly resistant to cassava lace bug. This study showed that there are resistance mechanisms to V. illudens in cassava cultivars, which justifies the new studies on these cultivars in breeding programs, aiming to control this pest and identification of such mechanisms.