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[en] The biology and predatory potential of Coccinella septempunctata (Linn.) were studied on aphid, Schizaphis graminum (Rondani) at three constant temperatures 20+-1 degree C, 25+-1 degree C and 30+-1 degree C in Insectary-Bio Control Laboratories, National Agricultural Research Centre (NARC), Islamabad. The results revealed that incubation period of C. septempunctata was 5.12, 3.62 and 3.20 days with 75.6%, 82.0% and 71.2% hatchability, respectively. The larval durations were 29.5, 15.9 and 8.1 days with predatory potential of 573.7, 575.0 and 667.8 aphids per larvae. The results indicated that with increasing temperature, develop-mental duration decreases significantly. The pupal developmental duration was 14.0, 9.2 and 5.2 days, respectively which are significantly different from each other. The adult male and female longevity were 44.7, 37.7, 30.0 and 60.3, 58.9 and 43.7 days. Fecundity rate of females were 123.5, 251.5 and 293.2 eggs per female, respectively. This indicates that adult male and female developmental duration, female fecundity rate were significantly different from each other at three constant temperatures. Maximum female and male predatory potential was 3262.8 and 2571.7 aphids at 25 +-1 degree C while minimum was 2276.8 and 1890.6 aphids, respectively. (author)
[en] The aim of this work is to provide an insight into the aerodynamic performance of the beetle during takeoff, which has been estimated in previous investigations. We employed a scaled-up electromechanical model flapping wing to measure the aerodynamic forces and the three-dimensional flow structures on the flapping wing. The ground effect on the unsteady forces and flow structures were also characterized. The dynamically scaled wing model could replicate the general stroke pattern of the beetle's hind wing kinematics during takeoff flight. Two wing kinematic models have been studied to examine the influences of wing kinematics on unsteady aerodynamic forces. In the first model, the angle of attack is asymmetric and varies during the translational motion, which is the flapping motion of the beetle's hind wing. In the second model, the angle of attack is constant during the translational motion. The instantaneous aerodynamic forces were measured for four strokes during the beetle's takeoff by the force sensor attached at the wing base. Flow visualization provided a general picture of the evolution of the three-dimensional leading edge vortex (LEV) on the beetle hind wing model. The LEV is stable during each stroke, and increases radically from the root to the tip, forming a leading-edge spiral vortex. The force measurement results show that the vertical force generated by the hind wing is large enough to lift the beetle. For the beetle hind wing kinematics, the total vertical force production increases 18.4% and 8.6% for the first and second strokes, respectively, due to the ground effect. However, for the model with a constant angle of attack during translation, the vertical force is reduced during the first stroke. During the third and fourth strokes, the ground effect is negligible for both wing kinematic patterns. This finding suggests that the beetle's flapping mechanism induces a ground effect that can efficiently lift its body from the ground during takeoff. (paper)
[en] Studies to determine the effects of varying periods of diapause on the radiosensitivity of the larvae of Trogoderma granarium showed practically no mortality in the irradiated larvae during diapause, but only after the diapause was broken at 38°C. As the calculated LD50S for 10, 20 and 30 days of post-irradiation diapause were not significantly different, it was also evident that increases in the length of diapause time had no significant effect on post-diapause survival time. On the other hand, pupation seemed to be influenced by tile duration of diapause in the irradiated larvae. This effect was best discernible ar low doses. The significance of these findings is discussed. (author)
[en] Red wood ant (Formica rufa group) nests contain a highly diverse community of invertebrates, which is largely due to their abundant resources and regulated microclimatic conditions. Clear-felling, however, causes nest mounds to lose surface layer moisture, thus disrupting their inner stability. To study the effects of clear-felling on ant-associated beetles (myrmecophile and non-myrmecophile), 41 nests of Formica aquilonia Yarrow, 1955 located on three clear-fells and adjacent mature forest stands were sampled, and the beetle communities between these habitats were compared. We investigated how habitat type, nest surface moisture content, nest volume, and isolation affect the community composition, species richness, and abundance of beetles. Beetle community composition or species richness did not markedly differ between clearings and forests, although total abundance was higher in forests. Also, total species richness and abundance and myrmecophile abundance increased with increasing moisture content. Overall, nests with similar moisture content and volume had similar species compositions. Nest volume was negatively correlated with myrmecophile species richness. Nest isolation was not related to species richness or abundance. The lower abundances in clearings could be problematic in the long term, as small populations are more likely to become extinct. To ensure the survival of ants and their associates, small-scale clearings should be preferred. (author)
[en] We present an unsteady blade element theory (BET) model to estimate the aerodynamic forces produced by a freely flying beetle and a beetle-mimicking flapping wing system. Added mass and rotational forces are included to accommodate the unsteady force. In addition to the aerodynamic forces needed to accurately estimate the time history of the forces, the inertial forces of the wings are also calculated. All of the force components are considered based on the full three-dimensional (3D) motion of the wing. The result obtained by the present BET model is validated with the data which were presented in a reference paper. The difference between the averages of the estimated forces (lift and drag) and the measured forces in the reference is about 5.7%. The BET model is also used to estimate the force produced by a freely flying beetle and a beetle-mimicking flapping wing system. The wing kinematics used in the BET calculation of a real beetle and the flapping wing system are captured using high-speed cameras. The results show that the average estimated vertical force of the beetle is reasonably close to the weight of the beetle, and the average estimated thrust of the beetle-mimicking flapping wing system is in good agreement with the measured value. Our results show that the unsteady lift and drag coefficients measured by Dickinson et al are still useful for relatively higher Reynolds number cases, and the proposed BET can be a good way to estimate the force produced by a flapping wing system.
[en] Full text:The main area of the Apsheron Peninsula, semi-complete urbanization area, where as a result of human impact, in particular oil production and processing large areas of once fertile land have been ruined. As a result, formed locally contaminated sites where the oil soaks into the soil to a depth of 1m or more, the mold is completely ruined. The aim of our research was to study the species composition of bugs, beetles, butterflies, bees in these locally contaminated areas of Absheron, their relationships and nutritive degree of occurrence. Expeditionary trips were made in the following areas: Karadag, Seaside, Bibi Geybatsky, Surakhani, Sabunchu Oil Gas Mining Management, Ramaninsky iodine plant. These areas are divided into three gradations of anthropogenic strain:1) The weak degree of load-zone relatively clean; 2) The average degree of load-space of moderate economic use; A strong degree of load-immediately adjacent to the locally-contaminated sites. According to the results of environmental monitoring of terrestrial invertebrates group found: bugs, 22 species, 10 species of beetles, butterflies, eight species of bee-25, found food and the degree of occurrence of communication. Identified several types of bee-bioindicators: Zholletes similes, Schylaeus variegate, Andrew Flavipes. Identification of these species will provide an opportunity to determine in advance the impact of background radiation in this ecosystem and to conduct cleaning, remediation work. On the basis of faunal material collected in Table 1 shows the species composition of the above insects, food relations and the degree of occurrence.
[en] During normal operations at the Department of Energy's Hanford Site in Hanford, WA, drugstore beetles were found within the fiberboard subassemblies of two 9975 Shipping Packages. The Department of Energy's Packaging Certification Program (EM-60) directed a thorough investigation to determine if the drugstore beetles were causing damage that would be detrimental to the safety performance of the Celotex. The Savannah River National Laboratory is continuing to conduct the investigation with entomological expertise being provided by Clemson University. The outcome from the investigation conducted over the previous year was that no discernible damage had been caused by the drugstore beetles. One of the two packages has been essentially untouched over the past year and has only been opened to visually inspect for additional damage. This paper will provide details and results of the ongoing investigation of that package.
[en] In this paper, we investigate a mathematical model for age-structured forest–beetle interactions that includes harvesting of trees. The aim is to broaden the understanding of the synergistic effects of harvesting and insect infestation on the age structure of the forests and the harvesting benefit. In the first part of this study, we consider different scenarios of the forest infestation by beetles and observe that the quantitative age profile of the forest depends significantly on whether the beetle population is in its endemic or epidemic states. In the second part, we also include harvesting of the forest trees and analyze two different harvesting strategies: cutting all trees older than a certain age, and cutting a fixed proportion of trees older than a certain age. Numerical simulations are implemented to determine the optimal cutting age for both harvesting strategies. The numerical simulations reveal that, independent of the steady state of the beetle population (that is, no beetles, endemic or epidemic state) clear cutting all trees older than a given age provides a higher harvesting benefit. Our numerical simulations further indicate that to obtain a fixed harvesting yield, a forest under a beetle epidemic state has to be cut at a younger age than if the forest were at an endemic beetle state or a no-beetle state.
[en] A physiological disorder known as spongy tissue involving damage of the mesocarp (flesh) affects 20 to 30 percent of mango fruits, particularly Alphonso, the leading commercial variety of India. Large sized fruits and those more advanced in maturity or harvested when ripe show increased incidence of spongy tissue. The mango processing industry is also facing quality control problems and economic loss as weevil-infested fruits can contaminate the processed pulp as well as the processing machinery with insect, fecal and feed remnants. Studies undertaken in the Food Technology Division, Bhabha Atomic Research Centre (BARC), Mumbai with assistance from Radiation Standards Section, Radiological Unit, BARC Hospital and ECIL, Hyderabad, have shown that both spongy tissue affected and seed weevil infested mango fruits can be detected by x-ray transmittance. The resulting image can be used to detect affected fruits. An automated system for detecting and rejecting mangoes with spongy tissue or seed weevil infestation is under development in collaboration with the Electronic Systems Division, BARC. (author)
[en] Egg incubation of Euscepes postfasciatus is a necessary step in the mass rearing of this species because its egg period is slightly long(mean, 8 days at 25 deg C). E. postfasciatus eggs tend to stick to each other during the incubation period. To ensure sufficient disinfection of the egg surface and an even distribution of the eggs on the artificial diet, it is necessary to separate the stuck eggs. The separation process is time-consuming; it can be shortened by ensuring, as far as possible, that the eggs are not in contact with each. The effect of the incubation condition on egg hatching of E. postfasciatus has not yet been examined; thus, we compared the parameters for hatching between eggs incubated en masse (the present method) and those that had been thinly dispersed (a newly tested method) . The eggs could be dispersed easily by putting eggs on a wellstrained nylon cloth and gently swaying the cloth in water. The hatchability, mean egg period, and variance of the egg period did not vary significantly between the two incubation conditions. The separation time of E. postfasciatus eggs can thus be shortened without any undesirable effects on egg hatching of the species