9 research outputs found

    Pollination of Grewia asiatica (Malvaceae) by Megachile cephalotes (Hymenoptera: Megachilidae): Male vs. Female Pollination

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    Phalsa, Grewia asiatica is a multi-purpose crop while cross-pollination can significantly improve its reproductive success. Megachile bees (Megachilidae) are the most important group of pollinators of G. asiatica. In this study we observed the foraging behavior of Megachile cephalotes and its ultimate impact on reproductive success of phalsa at Bahawalpur (Punjab), Pakistan. Although visitation rate and stay time were statistically similar in both the sexes but visitation frequency (2.06±0.14 individuals/120 seconds) and pollen deposition (39.35±3.17 pollen grains /stigma/visit) of females were significantly higher than that of males (0.44±0.06 individuals/120 seconds and 12.05±1.19 pollen grains/stigma/visit, respectively). The environmental factors (i.e. ambient temperature, relative humidity, sunlight intensity and wind speed) greatly influenced -either positively or negatively- both the sexes (Pearson’s correlation). Female pollinated fruits were significantly greater in weight (0.41±0.017 g) followed by open (0.31±0.012 g) and male (0.27±0.011 g) pollinated fruits. Percent weight loss remained significantly lower in female pollinated fruits than open and male pollinated fruits until12 hours after harvest. Fruit wrinkling significantly increased with the increase in post-harvest intervals in open, female and male pollinated fruits while fruit color changed only in female pollinated fruits. The results of present study suggest female M. cephalotes as the efficient pollinators of G. asiatica in terms of it reproductive success and post-harvest parameters. Future studies should focus biology and ecology of M. cephalotes with special focus on its artificial nesting

    Vector-Borne Disease and Climate Change

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    Many arthropod species are vectors of numerous diseases of humans and animals, which include ticks, fleas, sandflies, mosquitoes, triatomine bugs, and blackflies. The vector transmits bacteria, viruses, and protozoa from one host to another causing various diseases, such as dengue fever, West Nile Virus, Lyme disease, and malaria. They are scold-blooded animals and very sensitive to the fluctuation in climatic factors. Changing climate influences the survival, reproduction, abundance, and spatiotemporal distribution of vectors throughout the year and the rate of development and survival of pathogens within the vector-host. Climate change is among the prime factors that influence the survival, reproduction, distribution, and density of disease vectors

    Syngas production via bi-reforming of methane over fibrous KCC-1 stabilized ni catalyst

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    Bi-reforming of methane (BRM) technology has the potential to serve as an alternative energy source while also mitigating greenhouse gas emissions. However, the main hurdle in the commercialization of BRM is catalyst deactivation. In this study, the ultrasonic-assisted impregnation method was utilized to prepare a Ni-based catalyst supported on fibrous KCC-1 and tested in the BRM process. The prepared catalysts were characterized by XRD, BET, FESEM and TPR-H2 techniques to determine the textural and morphological properties of the catalyst. The catalytic performance was tested in a tabular fixed-bed continuous reactor at 800 °C with a stoichiometric feed ratio of 3:2:1 for CH4: H2O: CO2. For high nickel loadings, it was discovered that agglomerates of the Ni-active phase form on the surface of the support. The catalysts with a 10 wt% Ni content produced the best CO2 (79.2%) and CH4 (82.1%) conversions, as well as an optimum H2/CO = 1.62 ratio

    Compatibility of entomopathogenic fungi and botanical extracts against the wheat aphid, Sitobion avenae (Fab.) (Hemiptera: Aphididae)

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    Abstract Wheat aphid, Sitobion avenae (Fab.), is a serious pest of wheat crop across the world. The present study was conducted to evaluate the potentials of the water plant extracts of Azadirachta indica (neem) or Eucalyptus camaldulensis and the entomopathogenic fungi (EPF); Beauveria bassiana or Metarhizium anisopliae against the aphid species. After 5 days of applications, the combined mixture of B. bassiana and eucalyptus extract caused the maximum mortality rate (87%). While the combination of B. bassiana with neem extract showed the least rate (54%). Fecundity was negatively affected by the single and combined treatments of EPF and botanicals extracts. The lowest fecundity (7 nymphs per female) was recorded when the aphid was treated by the binary mixture of B. bassiana and eucalyptus extract. Correspondent maximum fecundity (29 nymphs per female) in 5 days was recorded in control treatment, while 23 nymphs were produced by a single female when treated with the binary mixture of B. bassiana and neem extract. The results indicated that EPF and botanical extracts (neem or eucalyptus) caused significant reduction in survival and fecundity of S. avenae. Therefore, they may be used as promising natural alternatives to synthetic insecticides against the wheat aphid species

    Plant communities exhibit low resource partitioning for pollinator guilds under sub-tropical conditions of Pakistan.

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    Assessment of resource partitioning in pollinators at a particular place can be used to conserve plant communities by minimizing their inter-specific competition. Current study was conducted to investigate the occurrence of this phenomenon among plant communities under sub-tropical conditions for the first time in Pakistan. We considered the entire available flowering plant and floral visitor communities in the study area-Lal Suhanra forest of Bahawalpur, Pakistan- along with different variations among them based on morphology, color and symmetry (functional groups) i.e. four functional groups among insects and nine among plants. Weekly floral visitor censuses were conducted during spring season -from the first week of March to the fourth week of May 2018. Thirty individuals of each plant species -in bloom- were observed for floral visitors in each census. Plant species with different floral shapes, colors and symmetry did not show any significant resource partitioning. The Non-metric multidimensional scaling analysis followed by one-way ANOSIM test showed non- significant differences among all the pair of floral shapes, colors (except white and yellow) and symmetry (R-value < 0.168). However, SIMPER test suggested that flies were the most common group that contributed more towards within group similarities of different floral shapes (19 to 21% similarity), colors (16 to 30%) and symmetry (19%) followed by long-tongue bees i.e. 14 to 21%, 9 to 19% and 18%, respectively. Our results suggest that plant communities under sub-tropical conditions of Pakistan exhibit a generalist pollination system with no significant resource partitioning in pollinator species. Therefore, plant communities may have high competition for pollinator species which exhibits fewer implications of species loss on overall pollination process. Our study provides the basis for understanding the partitioning of pollinator guilds under sub-tropical conditions. Future studies should focus on functional traits in more detail at the community and the population scales for their possible impact on resource partitioning

    Influence of Bacterial Secondary Symbionts in Sitobion avenae on Its Survival Fitness against Entomopathogenic Fungi, Beauveria bassiana and Metarhizium brunneum

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    The research was focused on the ability of wheat aphids Sitobion avenae, harboring bacterial secondary symbionts (BSS) Hamiltonella defensa or Regiella insecticola, to withstand exposure to fungal isolates of Beauveria bassiana and Metarhizium brunneum. In comparison to aphids lacking bacterial secondary symbionts, BSS considerably increased the lifespan of wheat aphids exposed to B. bassiana strains (Bb1022, EABb04/01-Tip) and M. brunneum strains (ART 2825 and BIPESCO 5) and also reduced the aphids' mortality. The wheat aphid clones lacking bacterial secondary symbionts were shown to be particularly vulnerable to M. brunneum strain BIPESCO 5. As opposed to wheat aphids carrying bacterial symbionts, fungal pathogens infected the wheat aphids lacking H. defensa and R. insecticola more quickly. When treated with fungal pathogens, bacterial endosymbionts had a favorable effect on the fecundity of their host aphids compared to the aphids lacking these symbionts, but there was no change in fungal sporulation on the deceased aphids. By defending their insect hosts against natural enemies, BSS increase the population of their host society and may have a significant impact on the development of their hosts
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