111 research outputs found

    Distribution of insect pests and their natural enemies in a barley pile

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    The distribution and abundance of stored product pests and their natural enemies infesting the upper layer of a barley pile was assessed in this study. Sampling was carried out on a monthly basis from February to December 2009. Insects were sampled with a grain trier and pitfall traps. Yellow sticky traps were also used to capture flying insects. Most abundantly captured species were, in order of abundance: Rhyzopertha dominica, Sitophilus granarius, and Latheticus oryzae. Fewer individuals of other species were occasionally captured, such as Cryptolestes ferrugineus, Oryzaephilus surinamensis, Lasioderma serricorne and Stegobium paniceum. Concerning Hymenoptera, the species Anisopteromalus calandrae and Cephalonomia waterstoni were abundantly captured with yellow and pitfall traps, while lower numbers were captured with the grain trier trap. Comparing pitfall and grain trier captures, in the former one, natural enemies were abundantly captured, whilst captures with the grain trier were punctual. The predator Withius piger (Pseudoscorpionida: Withiidae) was captured both with grain trier and pitfall traps. Its captures peaked in August-September. The abundance of coleopteran pests varied among the different depths sampled and the time of the year. The highest captures of pests occurred in March and May; the natural enemy A. calandrae peaked in April, and C. waterstoni was scarcely captured. The three species of natural enemies were occasionally found in the deepest samples, thus, they were able to penetrate around 80-cm deep in the grain searching for their hosts.Keywords: Grain, Sampling, Biological control, Host finding

    The use of carbon dioxide in big bags and containers for the control of pest in food products

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    Modified atmospheres (MA) based on high carbon dioxide (CO2) contents offer an alternative to synthetic chemical fumigation for insect pest control in food commodities during storage and shipment processes. The present study aimed to establish the efficacy of using CO2 in big bags and containers to prevent pests’ development. Four trials were conducted with gastight big bags (900 x 900 x 1000 or 1600 cm). Two of these trials were conducted with polished rice and samples of Sitophilus oryzae, one trial with chamomile infested with Lasioderma serricorne and one trial with cocoa and samples of Tribolium confusum and Ephestia kuehniella. Initial contents of CO2 were higher than 75%, which decreased depending on exposure time (13 to 90 d) and food product. In all four trials the insects present in the infested samples were controlled with the MA. An additional trial was conducted in a 9 m container containing dried herbs in boxes, big bags and other pacaging formats. Twelve infested samples of L. serricorne and Plodia interpunctella were distributed uniformly at the bottom and top of the container. A concentration between 70% and 15% CO2 was maintained for an exposure time of 18 d. In spite of the decrease in CO2 content, the treatment was also effective to control all insects present in the samples. Our results confirmed that CO2 could be applied to food products during the storage in big bags and containers to control the occurrence of pests. Keywords: Modified atmosphere, Carbon dioxide, Pest control, Stored-product pests

    Biological control of Acanthoscelides obtectus and Zabrotes subfasciatus in stored dried beans

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    This study assesses the feasibility of using natural enemies for the control of Acanthoscelides obtectus Say and Zabrotes subfasciatus Boheman (Coleoptera: Chrysomelidae), key pests of stored dried beans, Phaseolus vulgaris L. (Fabales: Fabaceae). The predatory mites Blattisocius tarsalis Berlese (Acari: Ascidae) and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) were able to prey on A. obtectus eggs, reducing the bruchid population by more than 60% under both controlled and warehouse conditions. Therefore, they show good potential as biological agents for controlling this pest. The larval parasitoids Anisopteromalus calandrae Howard and Lariophagus distinguendus Förster (Hymenoptera: Pteromalidae) were both moderately effective (34–38% reduction) at suppressing A. obtectus populations, but when A. calandrae was combined with B. tarsalis, a significant improvement in control efficacy (81% reduction in emergence) was observed. Therefore, the release of A. calandrae combined with B. tarsalis seems to be a promising strategy for controlling A. obtectus. Neither B. tarsalis nor A. swirskii were able to prey on Z. subfasciatus eggs. Only the parasitoid A. calandrae was moderately effective (39% reduction) at supressing Z. subfasciatus populations. Further testing is needed to identify other natural enemies that can complement the action of A. calandrae in reducing Z. subfasciatus populations.info:eu-repo/semantics/acceptedVersio

    Susceptibility of Rhyzopertha dominica to high CO2 modified atmospheres in packaged chickpeas

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    Three MAs with 50%, 70% and 90% CO2 in air was tested at different exposure times on all the developmental stages of R. dominica using chickpeas packed with 4% and 96% filling ratio in which there was excess of CO2. At 4% filling ratio the loss of the gas was negligible. The exposure time to reach 50% mortality (LT50) was estimated for each developmental stage and CO2 concentration, ranging from 7 h for larvae with 90% to 2 days for pupae with 50% CO2. At 96% filling ratio and for the intervals of the estimated exposure times (LT50) from the 4% filling ratio, mortality decreased significantly for eggs and adults at the three MAs tested, while for the internal developmental stages, larvae at 50% and 70% CO2 and pupae in all concentrations of CO2, the susceptibility remained the same as with a 4% filling ratio. This decline in mortality of the external developmental stages was possible due to the sorption of CO2 by the chickpeas, which caused a loss of intergranular levels of CO2 between 17% and 29%. This sorption ranged from 0.1955 to 0.3285 g of CO2 per kg of chickpeas and produced a negative pressure of 77.12 to 60.65 kPa. In conclusion, when chickpeas are packed with high CO2 MAs, a decrease in the mortality of eggs and adults of R. dominica could be expected due to pulse sorption.info:eu-repo/semantics/acceptedVersio

    Non-chemical alternative in rice storage: the use of refrigeration for insect control and quality maintenance of paddy rice

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    Trials were conducted to evaluate the potential effects of refrigeration in controlling insect infestations of Sitophilus zeamais and S. oryzae on stored rice. In the rice storage and processing industry use of aeration systems during winter and refrigeration units under summer conditions can provide a good solution to reduce paddy temperature for control of insects and maintenance of paddy quality; though it is restricted by costs of machinery and electric power. Trials were conducted in a rice mill in Portugal close to the Mondego Valley. A granary containing 140 t of paddy (variety Ripallo) was cooled using refrigerated aeration because during the trials ambient temperatures were too high for successful insect control by ambient air aeration. Sitophilus zeamais and S. oryzae adults reared on brown rice at 28°C and 68±3% r.h. were used as bioassays. Paddy stored in the granary was cooled to below 18ºC from 27 June 2008 to 19 September 2008. The mean ambient temperature during the total period of the trial varied from 12ºC to 27ºC. The moisture content of the paddy in the granary ranged from 12.1% to 13.9% during the same period of time. The total F1 of adult emergence population of S. zeamais and S. oryzae was counted after the experiments. The F1 adult from parent adults of S. zeamais was reduced up to 77%; the F1 adult from eggs of S. zeamais and S. oryzae were also reduced up to 71% and 45%, respectively, when compared with corresponding untreated controls. Refrigeration of the paddy allowed storage for almost three months at about 18ºC and caused delay in rice weevils development. As a consequence, this negated the necessity for fumigation. Although the energy consumed during refrigeration doubled the cost when compared with cooling using an ambient-air, aeration system during the cold season, refrigeration provided an environmentally sound and user-friendly treatment during warm months of the year. Keywords: Refrigeration, Sitophilus zeamais, Sitophilus oryzae, Paddy, Rice mill, Storag

    Optimization of a Banker Box System to Rear and Release the Parasitoid Habrobracon hebetor (Hymenoptera: Braconidae) for the Control of Stored-Product Moths

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    Pyralid moths, such as Ephestia kuehniella (Zeller) or Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), are among the pests of most concern in mills and food industries worldwide. One option for their control, which presents an alternative to the application of insecticides, is the release of natural enemies. Habrobracon hebetor (Say) (Hymenoptera: Braconidae) is a larval parasitoid of pyralid moths that is commercially available for augmentative release in storehouses. They are delivered as adults that limit their performance. To improve their quality when released at the target location, a banker box has been developed consisting of a rearing box that optimizes the release of the parasitoid. In the present study, the nonpest larvae Galleria mellonella (L.) (Lepidoptera: Pyralidae) have been used as a host, substituting for E. kuehniella larvae which were used in the previous design. The best results were obtained when a mixture of two larval sizes of the host were offered to the female parasitoid, producing five times more adults than with E. kuehniella larvae. Quality of the released parasitoids was optimal because they were delivered in the pupal stage inside the rearing box and adults began to emerge in situ. The banker box released adult parasitoids over a prolonged period of approximately 25 d at the target location. The use of this banker box may significantly help in the biological control of stored-product moths.Los pirálidos Ephestia kuehniella (Zeller) y Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) se encuentran entre las plagas más preocupantes de los molinos y las industrias alimentarias de todo el mundo. Una alternativa a la aplicación de insecticidas para su control es la liberación de enemigos naturales. Habrobracon hebetor (Say) (Hymenoptera: Braconidae) es un parasitoide de larvas de pirálidos que está disponible comercialmente para su introducción en almacenes de la industria agroalimentária. Estos parasitoides se envían normalmente como adultos lo que limita su efectividad. Para mejorar su calidad cuando se liberan en el destino, se ha desarrollado una ‘banker box’ consistente en una caja de cría, que permite mejorar la calidad del parasitoide liberado. En este estudio, hemos mejorado esta ‘banker box’ utilizando como huésped la larva Galleria mellonella (L.) (Lepidoptera: Pyralidae), especie que no es plaga en almacenes, en sustitución de las larvas de E. kuehniella que se utilizaron en el diseño anterior. Los mejores resultados se obtuvieron cuando se ofreció a la hembra del parasitoide una mezcla de dos tamaños de larvas del huésped, produciéndose cinco veces más adultos que con las larvas de E. kuehniella. La calidad de los parasitoides liberados fue óptima porque se distribuyeron en la fase de pupa, y los adultos comenzaron a emerger ya in situ. La ‘banker box’ liberó parasitoides durante un período prolongado de aproximadamente 25 días. El uso de esta ‘banker box’ puede ayudar a mejorar significativamente el control de las polillas que atacan los productos alimenticios almacenados.info:eu-repo/semantics/acceptedVersio

    Impact of intercurrent introduction of steroids on clinical outcomes in advanced non-small-cell lung cancer (Nsclc) patients under immune-checkpoint inhibitors (ici)

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    Background: Baseline steroids before ICI have been associated with poor outcomes, particularly when introduced due to cancer symptoms. Methods: Retrospective analysis of advanced NSCLC patients treated with ICI. We collected the use of intercurrent steroids (≥10 mg of prednisone-equivalent) within the first eight weeks of ICI. We correlated steroid use with patient outcomes according to the indications. Results: 413 patients received ICI, 299 were steroids-naïve at baseline. A total of 49 patients received intercurrent steroids (16%), of whom 38 for cancer-related symptoms and 11 for other indications, such as immune-related events. Overall, median (m) progression-free survival (PFS) was 1.9 months (mo.) [95% CI, 1.8-2.4] and overall survival (OS) 10 mo. [95% CI, 8.1–12.9]. Intercurrent steroids under ICI correlated with a shorter PFS/OS (1.3 and 2.3 mo. respectively, both p < 0.0001). Intercurrent steroids for cancer-related symptoms correlated with poorest mPFS [1.1 mo.; 95% CI, 0.9–1.5] and mOS [1.9 mo.; 95%CI, 1.5–2.4; p < 0.0001)]. No mOS and mPFS differences were found between cancer-unrelated-steroid group and no-steroid group. Steroid use for cancer-related symptoms was an independent prognostic factor for poor PFS [HR 2.64; 95% CI, 1.2–5.6] and OS [HR 4.53; 95% CI, 1.8–11.1], both p < 0.0001. Conclusion: Intercurrent steroids during ICI had no detrimental prognostic impact if the indication was unrelated to cancer symptoms
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