O objetivo deste trabalho foi determinar as doses de radiação gama que impedissem a emergência de adultos de Ceratitis capitata, a partir de ovos irradiados em dieta artificial e em frutos de manga. Quinhentos ovos de 6, 12, 24 e 48 horas de idade foram irradiados em cada dose. A infestação artificial de ovos ocorreu em mangas das cultivares Haden, Tommy Atkins ou Keitt. Um aumento da radioresistência de ovos foi observado durante o desenvolvimento embrionário, e para ovos de 48 horas em dieta artificial, foi estimado um Probit 9 de 24,67Gy. Não foi observada influência significativa dos frutos de manga na eficiência da irradiação dos ovos, quando comparada com os testes em dieta artificial.
The objective of this study was to establish gamma radiation doses required to prevent emergence of Ceratitis capitata (Wied.) adults, from irradiated eggs in artificial diet and mango fruits. Six-, twelve-, twenty-four- and fourty-eight-hour-old eggs were used. Artificial infestation by C. capitata was carried out in mangoes of `Haden', `Tommy Atkins' and `Keitt' cultivars. An increase of radiation resistance of C. capitata eggs was observed as a function of the embryonic development and a Probit 9 of 24.67Gy was estimated for 48-hour-old eggs in artificial diet. No significant influence of mango fruits was found on the efficacy of irradiation

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perplexansBlack streak disease of edible burdock (Arctiurn lappa L.) has been observed periodically in Hokkaido Prefecture, Japan since 1988. Symptoms appeared initially as small, dark brown to black spots on the leaf veins and petioles. The necrotic spots developed longitudinally along the leaf veins or petioles. Diseased leaf veins or petioles occasionally snapped off at the necrotic lesions. An Itersonilia sp. was isolated from rotting leaf veins and petioles. Laboratory inoculations of edible burdock seedlings using ballistospore suspensions produced typical symptoms observed in nature. The fungus had a feathery mycelium and developed a white to pale cream colony color. The mycelium was composed primarily of branched hyphae with clamp connections at the septa. Ballistospores, formed at the apex of inflated cells, were lunate, ovoid to pyriform. The fungus occasionally produced appressoria, chlamydospores and yeast cells. Based on the morphological characteristics, the causal agent was identified as Itersonilia perplexans Derx. Edible burdock strains were also pathogenic to chrysanthemum and caused petal blight. This report is the first of a foliar disease of edible burdock caused by I. perplexans in Japan.