Monitoramento de parasitoides de lagartas de Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) em municípios de Minas Gerais, Brasil.

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Survey of ear flies (Diptera, Ulidiiae) in maize (Zea mays L.) and a new record of Euxesta mazorca Steyskal in Brazil.

Survey of ear flies (Diptera, Ulidiidae) in maize (Zea mays L.) and a new record of Euxesta mazorca Steyskal in Brazil. Species of Euxesta (Diptera, Ulidiidae), known as silk flies or ear flies, are becoming increasingly important as maize insect pests in South America, although very little is known about them in Brazil. The larvae of some species of this genus initially damage female reproductive tissues, and then the developing kernels on the ear. As a result of feeding, fermentation and associated odors cause complete loss of the grain because it is no longer fit for human or livestock consumption. The main objective of th is work was to evaluate the incidence of Euxesta spp. in Brazilian maize fields and to determine the most prevalent species using two different hydrolyzed protein foods attractants, BioAnastrepha® (hydrolyzed maize protein) and Torula, placed inside McPhail traps. The two species identified were E. eluta Loew and E. mazorca Steyskal, the latter being a new record from Brazil. Between the two species, E. eluta was the more abundant in maize fields. Both attractants were efficient in capturing the two species. However, BioAnastrepha® captured significantly more insects than Torula. Levantamento de mosca-da-espiga (Diptera: Ulidiidae) em milho (Zea mays L.) e primeiro relato de ocorrência de Euxesta mazorca Steyskal no Brasil. Espécies de Euxesta (Diptera, Ulidiidae), conhecidas como moscas do cabelo ou moscas da espiga estão aumentando em importância nas culturas de milho em diferentes países, embora muito pouco se conheça sobre elas no Brasil. As larvas das espécies representativas de Ulidiidae inicialmente danificam a parte reprodutiva feminina da planta e depois os grãos em desenvolvimento. Como resultado da alimentação das larvas ocorre fermentação e odor forte tornando a espiga inapropriada para o consumo humano ou animal. O principal objetivo deste trabalho foi avaliar a incidência de espécies de Euxesta em áreas de produção de milho e identificar as espécies predominantes usando dois atraentes alimentares diferentes à base de proteínas hidrolisáveis, BioAnastrepha® (proteína hidrolisável de milho) e Torula, colocados no interior de armadilha McPhail. As duas espécies identificadas foram E. eluta Loew and E. mazorca Steyskal, registrada pela primeira vez no Brasil. Entre as espécies, E. eluta foi predominante no milho. Ambos os atraentes foram eficientes na captura das duas espécies. No entanto, as armadilhas com BioAnastrepha® capturaram significativamente mais insetos do que aquelas com Torula

A diamond detector based dosimetric system for instantaneous dose rate measurements in FLASH electron beams

Objective. A reliable determination of the instantaneous dose rate (I-DR) delivered in FLASH radiotherapy treatments is believed to be crucial to assess the so-called FLASH effect in preclinical and biological studies. At present, no detectors nor real-time procedures are available to do that in ultra high dose rate (UH-DR) electron beams, typically consisting of μs pulses characterized by I-DRs of the order of MGy/s. A dosimetric system is proposed possibly overcoming the above reported limitation, based on the recently developed flashDiamond (fD) detector (model 60025, PTW-Freiburg, Germany). Approach. A dosimetric system is proposed, based on a flashDiamond detector prototype, properly modified and adapted for very fast signal transmission. It was used in combination with a fast transimpedance amplifier and a digital oscilloscope to record the temporal traces of the pulses delivered by an ElectronFlash linac (SIT S.p.A., Italy). The proposed dosimetric systems was investigated in terms of the temporal characteristics of its response and the capability to measure the absolute delivered dose and instantaneous dose rate (I-DR). A ‘standard’ flashDiamond was also investigated and its response compared with the one of the specifically designed prototype. Main results. Temporal traces recorded in several UH-DR irradiation conditions showed very good signal to noise ratios and rise and decay times of the order of a few tens ns, faster than the ones obtained by the current transformer embedded in the linac head. By analyzing such signals, a calibration coefficient was derived for the fD prototype and found to be in agreement within 1% with the one obtained under reference 60Co irradiation. I-DRs as high as about 2 MGy s−1 were detected without any undesired saturation effect. Absolute dose per pulse values extracted by integrating the I-DR signals were found to be linear up to at least 7.13 Gy and in very good agreement with the ones obtained by connecting the fD to a UNIDOS electrometer (PTW-Freiburg, Germany). A good short term reproducibility of the linac output was observed, characterized by a pulse-to-pulse variation coefficient of 0.9%. Negligible differences were observed when replacing the fD prototype with a standard one, with the only exception of a somewhat slower response time for the latter detector type. Significance. The proposed fD-based system was demonstrated to be a suitable tool for a thorough characterization of UH-DR beams, providing accurate and reliable time resolved I-DR measurements from which absolute dose values can be straightforwardly derived