Two species of Compsus Schoenherr, new citrus pests from Colombia (Coleoptera: Curculionidae: Entiminae)

Two species of the weevil genus Compsus Schoenherr (Coleoptera: Curculionidae: Entiminae) from Colombia are redescribed: C. obliquatus Hustache and C.viridivittatus (Guérin-Méneville). A key by Hustache in 1938, to 33 of the 34 recognized species of Colombian Compsus then known, is modified to include the one additional species. Habitus illustrations of males and females of the two species and illustrations of selected parts of the male and female genitalia are included. Nearly all of the specimens of these two species were collected on various species or varieties of citrus, indicating their potential as citrus pests in the future.Se redescriben dos especies de picudos del genero Compsus Schoenherr (Coleoptera: Curculionidae: Entiminae) colectadas en Colombia: C. obliquatus Hustache y C. viridivittatus (Guérin-Méneville). Se modifica la clave de identificación de Hustache de 1938 la cual incluye 33 a 34 especies conocidas de Compsus en ese entonces en Colombia. Se incluyen ilustraciones con las características físicas de machos y hembras de ambas especies e ilustraciones de partes seleccionadas de la genitalia de machos y hembras de las dos especies. Casi todos los especímenes de estas dos especies fueron colectadas en varias especies o variedades de cítricos, lo cual indica su futuro potencial como plagas de cítricos

Development and Sex Ratio of \u3ci\u3eMelittobia Australica\u3c/i\u3e and \u3ci\u3eM. Digitata\u3c/i\u3e (Hymenoptera: Eulophidae) on \u3ci\u3eMegachile Rotundata\u3c/i\u3e (Hymenoptera: Megachilidae) and \u3ci\u3eTrypoxylon Politum\u3c/i\u3e (Hymenoptera: Sphecidae)

Life history, development time, and sex ratio of Melittobia australica Girault and M. digitata Dahms on Megachile rotundata (Fabricius) and Trypoxylon politum Say are presented and compared with previous reports. Total development time and sex ratio differs slightly among the different hosts but falls within the expected range reported for different hosts and Melittobia species. The slightly longer development times and higher proportion of males recorded for both species on M. rotundata hosts probably reflects poorer host nutritional quality, relative to T. politum. We confirm that the one unusually extended development time reported by Schmieder for Melittobia chalybii Ashmead collected in New Jersey, can be accounted for as likely having represented a previously unknown species since described as M. femorata Dahms

Cricket antennae shorten when bending (Acheta domesticus L.).

Insect antennae are important mechanosensory and chemosensory organs. Insect appendages, such as antennae, are encased in a cuticular exoskeleton and are thought to bend only between segments or subsegments where the cuticle is thinner, more flexible, or bent into a fold. There is a growing appreciation of the dominating influence of folds in the mechanical behavior of a structure, and the bending of cricket antennae was considered in this context. Antennae will bend or deflect in response to forces, and the resulting bending behavior will affect the sensory input of the antennae. In some cricket antennae, such as in those of Acheta domesticus, there are a large number (>100) of subsegments (flagellomeres) that vary in their length. We evaluated whether these antennae bend only at the joints between flagellomeres, which has always been assumed but not tested. In addition we questioned whether an antenna undergoes a length change as it bends, which would result from some patterns of joint deformation. Measurements using light microscopy and SEM were conducted on both male and female adult crickets (Acheta domesticus) with bending in four different directions: dorsal, ventral, medial, and lateral. Bending occurred only at the joints between flagellomeres, and antennae shortened a comparable amount during bending, regardless of sex or bending direction. The cuticular folds separating antennal flagellomeres are not very deep, and therefore as an antenna bends, the convex side (in tension) does not have a lot of slack cuticle to "unfold" and does not lengthen during bending. Simultaneously on the other side of the antenna, on the concave side in compression, there is an increasing overlap in the folded cuticle of the joints during bending. Antennal shortening during bending would prevent stretching of antennal nerves and may promote hemolymph exchange between the antenna and head

Multiple dynamical components in Local Group dwarf spheroidals

The dwarf spheroidal (dSph) satellites of the Local Group have long been thought to be simple spheroids of stars embedded within extended dark matter halos. Recently, however, evidence for the presence of spatially and kinematically distinct stellar populations has been accumulating. Here, we examine the influence of such components on dynamical models of dwarf galaxies embedded in cold dark matter halos. We begin by constructing a model of Andromeda II, a dSph satellite of M31 which shows evidence for spatially distinct stellar components. We find that the two-component model predicts an overall velocity dispersion profile that remains approximately constant at $\sim 10 - 11$ km s$^{-1}$ out to $\sim 1$ kpc from the center; this is despite wide kinematic and spatial differences between the two individual components. The presence of two components may also help to explain oddities in the velocity dispersion profiles of other dSphs; we show that velocity dispersion profiles which appear to rise from the center outwards before leveling off--such as those of Leo I, Draco, and Fornax--can result from the gradual transition from a dynamically cold, concentrated component to a second, hotter, and more spatially extended one, both in equilibrium within the same dark halo. Dwarf galaxies with two stellar components generally have a leptokurtic line-of-sight velocity distribution which is well described by a double Maxwellian. Interestingly, we find that multiple equilibrium components could also provide a potential alternative origin for ``extra-tidal'' stars (normally ascribed to tidal effects) in situations where corroborating evidence for tides may be lacking.Comment: Accepted by MNRAS Letters. Revised version, with addition of new section and expanded discussio

STRUCTURAL CHANGE IN U.S. CHEESE MANUFACTURING: A TRANSLOG COST ANALYSIS OF A PANEL OF CHEESE PLANTS

Over the last 20 years the cheese manufacturing sector has become the most important market for U.S. farm milk. Using a plant-level dataset encompassing the 1972-1997 period we examine the production characteristics of this industry. Using the results obtained from our cost function we estimate a series of measures of input substitutability and scale economies.Agribusiness,