1,668 research outputs found
The multicolored Asian lady beetle : Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) ; a not so new invasive insect in Colombia and South America
The first reports of the multicolored Asian lady beetle Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) in Colombia appeared in 2011. However, based on museum insect specimens, the introduction of H. axyridis in Colombia occurred in 1989 or earlier, making it the second oldest record of the species in South America after the deliberate releases of the species in Argentina in 1986. Currently in Colombia, H. axyridis is well established and is here recorded from the States of Antioquia, Caldas, Cauca, Cundinamarca, Nariño, Tolima and Valle del Cauca.Los primeros reportes de la mariquita multicolor asiática Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) aparecieron en el 2011. Sin embargo, con base en colecciones de insectos en museos, la introducción de H. axyridis en Colombia ocurrió en 1989 o antes, haciendo que este sea el segundo registro más antiguo de esta especie en Sur América, después de las liberaciones intencionales de la especie en Argentina en 1986. Actualmente en Colombia, H. axyridis está bien establecida y aquí se reporta en los departamentos de Antioquia, Caldas, Cauca, Cundinamarca, Nariño, Tolima y el Valle del Cauca
Additions to the Hyperaspis Chevrolat (Coleoptera: Coccinellidae) fauna of South American, descriptions of nine new species, and recognition of Hyperaspis pectoralis Crotch as a valid species
Nine new species of Hyperaspis from various South American localities are described, illustrated, and compared with previously described taxa. New taxa are: Hyperaspis luciae, H. corcovado, H. divaricata, H. humboldti, H. mimica, H. praecipua, H. unimaculosa, H. drechseli, and H. esmeraldas. Hyperaspis pectoralis Crotch is recognized as a valid species of Hyperaspis and integrated into the existing classification
Descriptions of the male of Heterodiomus marchali Brèthes and a new species of Chilean Heterodiomus Brèthes (Coleoptera: Coccinellidae: Scymninae: Diomini)
Additions to the classification of South American Diomini are provided. Male genitalia of Heterodiomus marchali Brèthes are described and Diomus brethesi is newly described
Distribution functions for a family of axially symmetric galaxy models
We present the derivation of distribution functions for the first four
members of a family of disks, previously obtained in (MNRAS, 371, 1873, 2006),
which represent a family of axially symmetric galaxy models with finite radius
and well behaved surface mass density. In order to do this we employ several
approaches that have been developed starting from the potential-density pair
and, essentially using the method introduced by Kalnajs (Ap. J., 205, 751,
1976) we obtain some distribution functions that depend on the Jacobi integral.
Now, as this method demands that the mass density can be properly expressed as
a function of the gravitational potential, we can do this only for the first
four discs of the family. We also find another kind of distribution functions
by starting with the even part of the previous distribution functions and using
the maximum entropy principle in order to find the odd part and so a new
distribution function, as it was pointed out by Dejonghe (Phys. Rep., 133, 217,
1986). The result is a wide variety of equilibrium states corresponding to
several self-consistent finite flat galaxy models.Comment: 12 pages, 7 figures, updated version, accepted for publication in
Rev. Acad. Colomb. Cienc. Ex. Fis. Na
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