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[en] Five species of army ants (Labidus coecus, Labidus coecus, Neivamyrmex punctaticeps, Cheliomyrmex andicola y Eciton dulcium) are recorded from land under seven different use regimes in Caqueta Department. The ants were captured in agricultural areas of the Amazonian foothills using four sampling methods (TSBF, screening of litter, formalin soil wash, and direct search). We provide information about distribution and habits for each species and report the presence of C. andicola and E. dulcium in Caqueta for the first time. These records contribute to a better knowledge of the ant fauna in Colombia.
[en] Eradication of new pests can avoid ongoing management costs. Although predominantly employed for suppression, classical biological control (CBC) may support eradication attempts, but also may cause non-target impacts in the long term. While CBC is potentially less costly than other approaches, complete eradication is difficult, especially when pests can sustain their populations at low levels. The sterile insect technique (SIT) involves the massrearing and release of sterilised insects to disrupt fecundity. This has proven to be synergistic with the release of biological control agents such as egg parasitoids. Here we describe a newly conceptualised tool, the ‘Kamikaze Wasp Technique’ (KWT), which uses a novel combination of CBC and SIT in an eradication to avoid impacts on non-target organisms. This technique proposes the release of sterile parasitoids, as irradiating mated female parasitoids can induce sterility without inhibiting their ability to kill the host. Future work should characterise the irradiation biology of parasitoids. Halyomorpha halys Stål (Hemiptera: Pentatomidae) and its natural enemy, Trissolcus japonicus Ashmead (Hymenoptera: Scelionidae), provide a model system for assessing the potential of the KWT. (author)
[en] The most efficient Levy flight (scale-free) searching strategy for N independent searchers to adopt when target sites are randomly and sparsely distributed is identified. For N=1, it is well known that the optimal searching strategy is attained when μ=2, where the exponent μ characterizes the Levy distribution, P(l)=l-μ, of flight-lengths. For N>1, the optimal searching strategy is attained as μ->1. It is suggested that the orientation flights of honeybees can be understood within the context of such an optimal cooperative random Levy flight searching strategy. Upon returning to their hive after surveying a landscape honeybees can exchange information about the locations of target sites through the waggle dance. In accordance with observations it is predicted that the waggle dance can be disrupted without noticeable influence on a hive's ability to maintain weight when forage is plentiful
[en] The change in the orbital period of the system WASP-46 due to quasi-static and dynamical tidal interactions is investigated. Various dissipation mechanisms are studied. In the case of quasi-static tides, dissipation is assumed to occur due to turbulent viscosity, while in the case of dynamical tides, two limiting cases are considered: the regime of moderately large dissipation and the regime of weak dissipation due to radiative viscosity. The change in the orbital period of WASP-46 is calculated and compared with observations. The regime of moderately large dissipation is shown to describe best the observations.
[en] The aim of this study is to evaluate chemical and biological profile of methanol extracts from Malaysian propolis produced by two commonly found sting less bee species, Heterotrigona itama (MHI) and Geniotrigona thoracica (MGT). Test samples were analyzed for physicochemical parameters such as moisture, fat, crude fibre, crude protein, carbohydrate and ash content. Tests for phyto chemical screening by thin layer chromatography of both extracts revealed that presence of terpenoids, flavonoids, phenols and essential oils but steroids, saponin and coumarins only occur in MHI. Both extracts displayed a characteristic profile and vary from each other. Accordingly, MHI possess higher antioxidant activity with an IC_5_0 of 15.0 ± 0.21 μg/ mL compared to MGT with IC_5_0 of 270.0 ± 0.19 μg/ mL. MHI showed moderate nitric oxide scavenging activity, while MGT only showed mild inhibition. Antidiabetic activity was determined by α-glucosidase inhibition and found significantly better than that of acarbose (positive control). In conclusion, data gathered in this study revealed that bee species play role in determining the chemical and biological profile of particular propolis and should put into account in decision of further development for propolis. (author)
[en] The construction process of the honeycomb by bees is an astonishing process. The original structure which the bees built is nothing more than a lot of rough cylinders. But keeping the beeswax semi-flow for a certain time, those rough structures become perfect hexahedral columns. A modified, simplified particle method was used here to simulate the semi-flow state of the material. Although the parameters used here were still rather subjective, the simulation still could demonstrate some behavior of that sort of material like beeswax. And the method that the bees used to build their honey comb, could be an efficient method to imitate when we are trying to manufacture cellular materials.
[en] Concern about the effects of environmental contaminants on immune function in both humans and wildlife is growing and practically nothing is known about this impact on terrestrial invertebrates, even though they are known to easily accumulate pollutants. We studied the effect of industrial heavy metal contamination on immune defense of a free-living wood ant (Formica aquilonia). To find out whether ants show an adapted immune function in a polluted environment, we compared encapsulation responses between local and translocated colonies. Local colonies showed higher heavy metal levels than the translocated ones but the encapsulation response was similar between the two groups, indicating that the immune system of local ants has not adapted to high contamination level. The encapsulation response was elevated in moderate whereas suppressed in high heavy metal levels suggesting higher risk for infections in heavily polluted areas. - Heavy metal pollution affects immune function in ants
[en] The honeybee Apis mellifera (Apidae) is a model widely used in behavior because of its elaborate social life requiring coordinate actions among the members of the society. Within a colony, division of labor, the performance of tasks by different individuals, follows genetically determined physiological changes that go along with aging. Modern advances in tools of molecular biology and genomics, as well as the sequentiation of A. mellifera genome, have enabled a better understanding of honeybee behavior, in particular social behavior. Numerous studies show that aspects of worker behavior are genetically determined, including defensive, hygienic, reproductive and foraging behavior. For example, genetic diversity is associated with specialization to collect water, nectar and pollen. Also, control of worker reproduction is associated with genetic differences. In this paper, I review the methods and the main results from the study of the genetic and genomic basis of some behaviors in bees.
[en] Networks and the associated tools from graph theory have now become well-established approaches to study natural as well as human-made systems. While early studies focused on topology and connectivity, the recent literature has acknowledged the importance of the dynamical properties of these networks. Here we focus on such a dynamic measure: accessibility. It characterizes for any given movement dynamics (such as random walks) the average number of nodes that can be reached in exactly h steps (out-accessibility), or the average number of nodes from which a given node can be reached (in-accessibility). This focus on dynamics makes accessibility particularly appropriate to study movement on networks and to detect complementary properties with respect to topology-based measurements such as betweenness centrality. We apply this measure to six nests of Cubitermes termites. Their mushroom-like 3D architectures consist of chambers and connecting tunnels that can be associated to nodes and edges in a communication network. Accessibilities turn out to be particularly low in the bottom part of the nests that link them to their underground tunneling network. We interpret this result in the context of anti-predator (ants) behavior and/or as a side effect of the global nest shape.