Los objetivos desarrollados en esta tesis doctoral se enmarcan dentro de los estudios dirigidos a contribuir al conocimiento de la diversidad de los Coleopteros Rutelinae neotropicales y su posible utilización como bioindicadores del estado de conservación de los ecosistemas en áreas tropicales. El objetivo general de esta investigación es contribuir a la clarificación taxonómica de los Anomalinos (Coleoptera: Scarabaeidae: Rutelinae), un grupo muy rico en especies, presentes en todo el mundo, varias de las cuales tienen importancia como plagas agrícolas. El estudio de esta tesis se ha centrado en los dos géneros más diversos en ecosistemas neotropicales que son Anomala y Callistethus. El estudio taxonómico se ha llevado a cabo en Costa Rica y se ha basado en especímenes depositados en las colecciones del Instituto Nacional de Biodiversidad (INBio), Costa Rica, y la Colección Entomológica de la Universidad de Alicante (CEUA). Asimismo, se han consultado las especies de este grupo depositadas en las principales colecciones europeas. Se han identificado un total de 78 especies de Anomala y 28 especies de Callistethus. Como resultado de las investigaciones conducentes a la elaboración de esta tesis doctoral, se han descrito un total de 57 especies nuevas de las cuales 44 son de Anomala y 13 de Callisthetus. Con este estudio se incrementa en 56 especies el conocimiento del grupo en Costa Rica, y por primera vez se hace un estudio del conjunto de sus especies aportando datos de su distribución. Para facilitar su identificación se ha elaborado una clave dicotómica general para la identificación de todas ellas. Asimismo, se ilustran por primera vez las genitalia masculinas para casi todas las especies, dado que son un importante elemento de diagnóstico que permite una rápida identificación de las especies. Se incluyen datos sobre las distribuciones de cada especie, más detalladas para las de nueva descripción. Con esta información se pretende paliar en gran medida la falta de conocimiento y de material bibliográfico de identificación para estos grupos en el Neotrópico con el fin de que puedan ser utilizados con mayor frecuencia en estudios de biodiversidad y como bioindicadores en estos ecosistemas tropicales. Se ha realizado un análisis filogenéticos basados en datos moleculares y morfológicos con el objeto de aclarar la situación taxonómica de los géneros Anomala y Callistethus, y en particular para determinar la composición de este último. Se ha pretendido aclarar la posición de algunas especies de dudosa asignación, así como identificar caracteres morfológicos con valor diagnóstico, principalmente en el pronoto y en el aparato genital masculino. El estudio realizado ha puesto de manifiesto que el género Anomala es en realidad un complejo formado por varios clados, y resulta por tanto parafilético ya que incluye a Callistethus y Anomalorhina. Por último, se ha analizado la estructura filogenetica de las comunidades ecológicas de estos dos géneros con objeto de investigar los mecanismos que dirigen los patrones de diversidad de estos géneros en Costa Rica; el principal resultado es que, en general, hay un filtro ecológico que condiciona la composición de las comunidades limitando la colonización de tipos de ambientes inestables.

In spite of the great economic importance of north American Scolytidae, many taxonomic descriptions remain inadequate for the identification of species, and existing keys have been made obsolete by the recent description of new species. To bring these keys up to date and make them useful to students and practical foresters, detailed studies of the morphological structure of the various species are necessary. The purpose of the present investigation has been to clarify and revise existing keys and to describe briefly the species of Scolytidae occurring in the Logan Canyon area of Utah. The following keys and descriptions will be of value to students, foresters, and taxonomists in identifying the species of Scolytidae occurring in northern Utah. Information secured in this investigation also contributes toward the geographic and host distributional knowledge of the Scolytidae in Utah.

Old hollow trees have declined in Europe and many saproxylic (wood-dwelling) beetles dependent on them are threatened. Several studies have been done on old hollow oaks and they have been shown to harbour a species-rich saproxylic beetle fauna. However, other broad-leaved trees might also be important to consider as supporting habitats. The aim of this study was to investigate to what extent saproxylic beetles are tree genus specialists. Pitfall traps and window traps were used to compare the saproxylic beetle fauna in oak, ash, norway maple and small-leaved lime in an area dominated by old oaks. 5,501 specimens of saproxylic beetles were found, belonging to 239 species of which 27 species were red-listed. There were significant differences in the saproxylic species composition between the four tree species, but with large overlaps. The saproxylic species found in oak overlapped to 66 % with norway maple, to 67 % with ash and to 70 % with small-leaved lime. About one third of the species in this study seem to be tree genus specialists. The conclusion is that other broad-leaved trees are important to consider in models as supporting habitats for oaks. However, to be able to save the whole fauna of saproxylic beetles, trees of all different tree species are needed.

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2006. / Härtill 6 uppsatser.

In nature, both fundamental and sophisticated ecological functionality alike are driven by the display or, conversely, the concealment of colour and visual contrast. Through scientific investigation, the evolutionary genius manifested in numerous light manipulating biological systems has provided many blueprints for innovative photonic devices and other smart materials. The development of innovative bioinspired materials that harness the optical properties exhibited by chiral structures, such as those found in certain Scarabaeidae, offer widespread potential. In this thesis, the species-specific circularly polarised optical behaviour corresponding to a variety of Scarabaeidae beetles is investigated. The helicoidal morphology giving rise to circularly polarised photonic properties is first described for several beetles displaying a narrowband colour appearance. A structural analysis of the native surface structures encountered in these species is presented alongside a discussion of their role in defining the species' optical characteristics. Experimental measurements of the circularly polarised scattering behaviour are presented and discussed with respect to the electron microscopy and surface morphology measurements comprising the structural analysis. Following this, the origins of the subtle differences in the metallic colour appearance of several broadband coleopteran structures are deciphered. The broadband response of these species is attributed to chirped configurations of the helicoidal lamellar structure, elucidated using electron microscopy. Results of this structural analysis are applied to theoretical simulations of the structures' electromagnetic response and consolidate experimental measurements of the circularly polarised reflectance. Rigorous experimental measurement demonstrated that the circularly polarised spectral response is relatively robust to small structural defects or `biological noise'. Building from this, the intraspecific colour variation displayed in the species Chrysina aurigans is a useful lens through which the nuances of the chirped multilayer structure are further examined. As a result, this work provides detailed insights into the fine-tuning of chirped biological photonic systems. Likewise, the topic of biological wave retarders is afforded significant attention, primarily with reference to the biological half-wave plate encountered in the cuticle structure of Chrysina resplendens. A rigorous analysis of the photonic system in C. resplendens is presented, leading to novel conclusions describing this system's opto-structural relationship. Additionally, this thesis reports, for the first time, the presence of a biological wave retarder in the cuticle structure of Chrysina cupreomarginata.

This thesis investigates the systematics and biology of Neotropical Cassidinae and summarizes available knowledge of all tribes occurring in the Neotropics. This study uses a multidisciplinary framework to evaluate various issues in the taxonomy of this diverse group of beetles as a result of extensive field research.

No description available.

Angl. resumé

The aim of this work was to examine the expression of certain Hsp genes upon heat exposure in spruce bark beetle Ips typographus. We determined the level in unstressed and heat-exposed animals, and attempted to assess the importance of Hsp proteins for animals' survival upon heat treatment. We used RNA interference to knock down the expression of these genes, and analyzed the influence on animals exposed to elevated temperatures.

This thesis refines and develops understanding of the ecological and climatic characteristics of early Middle Pleistocene (MIS 19-13, c. 780-430 ka) interglacial environments in Britain. This period is characterised by globally muted (i.e. low amplitude) glacial-interglacial cycles, which increased in amplitude c. 430 ka with the Mid-Brunhes Transition (MBT). However, the influence of these global climatic characteristics on climates and ecology at regional and local scales is yet to be fully understood. Local ecological processes, particularly disturbance processes, have also received limited attention in pre-Holocene interglacial settings, despite their likely importance for vegetation and habitat structure. Chapters 4, 5 and 6 present in-depth multi-proxy palaeoenvironmental studies from three early Middle Pleistocene sites: West Runton, Pakefield and Brooksby. A combination of Coleoptera, pollen, coprophilous fungal spores, microcharcoal and sedimentology is used to reconstruct local ecological attributes for each site. Multivariate analyses of these datasets indicate the importance of disturbance processes (herbivore activity, wildfire, hydrogeomorphic processes) in driving and maintaining local vegetation structure and habitat heterogeneity. This is explored further (in Chapter 8), emphasising the apparent importance of site-specific factors, rather than those shared between sites, in determining the relative influence of each disturbance factor. In Chapter 7, new approaches to the coleopteran Mutual Climatic Range (MCR) method are applied to a suite of coleopteran records from interglacial sites spanning the Middle and Late Pleistocene (c.712-126 ka, MIS 17-5e). Summer temperatures, winter temperatures and temperature seasonality are reconstructed, to test whether there is evidence for MBT expression in Northwest European thermoclimates. No evidence for this is found, and it is suggested (in Chapter 8) that MBT expression in this region may instead be reflected in hydroclimatic variables (e.g. enhanced annual precipitation). Finally, it is suggested that disturbance processes and potentially wetter climates were beneficial to contemporary Lower Palaeolithic populations in Northwest Europe.