513 research outputs found

    The Effect of Repeated Low Temperature on Eggs of the Alfalfa Weevil (Coleoptera: Curculionidae)

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    Three ages of alfalfa weevil, Hypera postica (Gyllenhal) eggs were exposed to repeated exposures of -15 and -20°C. Fresh-laid eggs were quite susceptible and 3- and 5day old eggs were relatively resistant to -15\u27C, but all ages of eggs showed considerable susceptibility to -20°C, with an average LT50 of 2.2 days. Comparison of this data with similar studies utilizing constant low temperature exposures showed the effect to be independent of temporal interruptions

    A Laboratory Infection of Alfalfa Weevil, \u3ci\u3eHypera Postica\u3c/i\u3e (Coleoptera: Curculionidae), Larvae With the Fungal Pathogen \u3ci\u3eZoophthora Phytonomi\u3c/i\u3e (Zygomycetes: Entomophthoraceae)

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    Larvae of the alfalfa weevil, Hypera postica, were infected by an in vitro colony of Zoophthora phytonomi. Two spore types (infective conidia, and resting spores) were produced from infection trials. The spore type produced may be influenced by the physiological state of the larvae. Trials using field collected larvae which would produce diapausing adults formed both conidia and resting spores. Trials using larvae from a nondiapausing colony, however, formed only resting spores

    An Alternative to Using Fresh Alfalfa for Culturing \u3ci\u3eColias Philodice Eurytheme\u3c/i\u3e Boisduval (Lepidoptera: Pieridae)

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    Various artificial materials were implemented at each life stage of the alfalfa caterpillar, Colias philodice eurytheme Boisduval, to provide effective and economical replacements for alfalfa. Alfalfa substitutes were used for oviposition and feeding. We also developed a favorable laboratory mating environment. Also, the development of a method for removing disease organisms from eggs without increasing egg mortality was an essential facet of this work. The performance of individuals on artificial surfaces was compared with similar individuals reared on greenhouse alfalfa. Green tape oriented at the top of oviposition cages or near some object which could be held on to while ovipositing was the most successful surface. Egg yields on green tape were comparable to those on alfalfa. A dilute bleach wash followed by two water washes required little time, yet provided adequate disease control, and all larval instars thrived on artificial diet. Methods for handling pupae and new adults and the favorable mating environment reduced colony maintenance time yet sumival rates insured propagation of the colony

    Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Coleoptera: Curculionidae) from Alfalfa Samples

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    A modified Berlese funnel system was developed to extract alfalfa weevil larvae (Hypera postica) from quadrats 30.5 cm on a side. Data from this system were comp.wed with simultaneous data from a hand sorting extraction system. In most instances, the modified Berlese system was as efficient as the hand sorting method and the number of man hours required to process samples by hand was far greater than that required by the Berlese system

    Disease as a Larval Mortality Factor in Alfalfa Weevil, \u3ci\u3eHypera Postica\u3c/i\u3e (Coleoptera: Curculionidae) Populations in Illinois

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    During the 1974 growing season, larvae of the alfalfa weevil, Hypera postica (Gyllenhal), were examined for pathogens. Three larvae out of 715 examined were infected with a microsporidium. This infection was present in both Washington and Mason counties in Illinois

    Two Trapping Systems to Determine Incidence and Duration of Migration of Adult Alfalfa Weevils, \u3ci\u3eHypera Postica\u3c/i\u3e (Coleoptera: Curculionidae)

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    Emergence and flight traps were used to study the pre- and post-diapause movements of the alfalfa weevil, Hypera postica. The emergence traps proved to be an excellent tool in determining the time of diapause termination and in providing an accurate accounting of the number of weevils per unit area in aestivation sites. The flight traps showed when diapause flights to and from alfalfa fields took place. Both trapping systems can be utilized in a pest control program to locate more closely where the alfalfa weevil aestivates and when diapause related movements occur

    Fall Termination of Aestivation and Field Dispersal of the Alfalfa Weevil (Coleoptera: Curculionidae) in Illinois

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    Emergence traps, flight traps, sweeping, and egg sampling were employed to determine fall termination of aestivation of the alfalfa weevil, Hypera postica, and patterns and timing of field reentry, and subsequent fall oviposition. Adult alfalfa weevils were found to terminate aestivation in wood edge field borders in mid-late October. Field reentry began in late October as a gradual process, starting at wooded field borders, with the field population equally dispersed by mid-November

    Effect on Constant Versus Fluctuating Temperature Regimes on \u3ci\u3eBathyplectes Curculionis\u3c/i\u3e (Hymenoptera: Ichneumonidae) Activity

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    Individual female Bathyplectes curculionis parasites were exposed to either a series of constant or fluctuating temperature regimes and supplied with a new group of host Hypera postica larvae every day. The fluctuating temperatures were calculated from an average of weekly air temperatures during a period of actual field oviposition by the parasite. The rearing of adult parasites under a constant versus fluctuating temperature regime resulted in no significant difference in parasitism, longevity, or fecundity. The threshold for B. curculionis activity was estimated to be 6-8°C

    The evolution of silicon transporters in diatoms

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    © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Phycology 52 (2016): 716–731, doi:10.1111/jpy.12441.Diatoms are highly productive single-celled algae that form an intricately patterned silica cell wall after every cell division. They take up and utilize silicic acid from seawater via silicon transporter (SIT) proteins. This study examined the evolution of the SIT gene family to identify potential genetic adaptations that enable diatoms to thrive in the modern ocean. By searching for sequence homologs in available databases, the diversity of organisms found to encode SITs increased substantially and included all major diatom lineages and other algal protists. A bacterial-encoded gene with homology to SIT sequences was also identified, suggesting that a lateral gene transfer event occurred between bacterial and protist lineages. In diatoms, the SIT genes diverged and diversified to produce five distinct clades. The most basal SIT clades were widely distributed across diatom lineages, while the more derived clades were lineage-specific, which together produced a distinct repertoire of SIT types among major diatom lineages. Differences in the predicted protein functional domains encoded among SIT clades suggest that the divergence of clades resulted in functional diversification among SITs. Both laboratory cultures and natural communities changed transcription of each SIT clade in response to experimental or environmental growth conditions, with distinct transcriptional patterns observed among clades. Together, these data suggest that the diversification of SITs within diatoms led to specialized adaptations among diatoms lineages, and perhaps their dominant ability to take up silicic acid from seawater in diverse environmental conditions.Gordon and Betty Moore Foundation Grant Numbers: GBMF2637, GBMF3776; University of Washington; National Science Foundation Grant Number: OCE-120523

    Role of FDG-PET/CT in children with fever of unknown origin

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    PURPOSE: To determine the role of 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET)/computed tomography (CT) in children with fever of unknown origin (FUO). METHODS: This retrospective single-center study included 110 children (0-18 years) with FUO who underwent FDG-PET/CT between 2010 and 2019. The diagnostic value of FDG-PET/CT for identifying cause of fever was calculated, treatment modifications after FDG-PET/CT were assessed, and logistic regression analyses were performed to identify clinical and biochemical factors associated with FDG-PET/CT outcome. RESULTS: In 53 out of 110 patients (48%), FDG-PET/CT identified a (true positive) cause of fever. Endocarditis (11%), systemic juvenile idiopathic arthritis (5%), and inflammatory bowel disorder (5%) were the most common causes of FUO. In 42 patients (38%), no cause of fever was found on FDG-PET/CT. In 58 out of 110 patients (53%), treatment modifications were made after FDG-PET/CT. FDG-PET/CT achieved a sensitivity of 85.5%, specificity of 79.2%, positive predictive value of 84.1%, and negative predictive value of 80.9%. On multivariate logistic regression, C-reactive protein was positively associated with finding a true positive focus of fever on FDG-PET/CT (OR = 1.01 (95% CI 1.00-1.02) per mg/L increase in CRP), while leukocyte count was negatively associated with finding a true positive focus of fever (OR = 0.91 (95% CI 0.85-0.97) per 109 leukocytes/L increase). CONCLUSION: FDG-PET/CT is a valuable diagnostic tool in the evaluation of children with FUO, since it may detect a true underlying cause in almost half (48%) of all cases where none was found otherwise. It allows full-body evaluation in patients without disease-specific symptoms on one examination. CRP and leukocyte count were significantly associated with FDG-PET/CT results, which may contribute to a priori assessment on the outcome of FDG-PET/CT. Future research could be aimed at evaluating more patient-specific factors to prospectively estimate the added value of FDG-PET/CT in children with FUO
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