Search

Reconstructing past environmental and climatic conditions allows us to better understand the impact of change on the environment, along with the taxa that inhabit it. This can help with constraining our predictions for future change and focus conservation efforts. As contemporary change is being experienced at an unprecedented rate within the Arctic, investigating past change within this region is of utmost importance. Northern Norway is known to have experienced significant environmental change throughout the Quaternary, alternating between being covered in ice and being ice-free, multiple times. The traditional view that temperate taxa survived periods of glaciation further south, in refugia, is brought into question by the discovery that survival in crypto-refugia on ice-free islands, such as Andøya, was possible. Little work has been undertaken to analyse these Quaternary climatic and environmental changes within northern Norway, despite the effectiveness of insects, especially beetles and chironomids, in reconstructing past environmental and climatic conditions, having been well demonstrated. Thus, the overall aim of this thesis is to use subfossil insects to reconstruct the environment and climate of northern Norway throughout the Late Quaternary (last 24,000 years), whilst testing their robustness as proxies within the region. In doing so, this study provides the longest high-resolution chironomid study, the earliest, and most complete, Holocene reconstructions using beetles in northern Norway, as well as the first multi-proxy insect study in the region. Chironomids have been investigated between 24.0 and 8.2 cal ka BP from Øvre Æråsvatnet (Andøya), and quantitative July temperature reconstructions have been made. Beetles were recovered from Ramså (Andøya) from 11.0 to 8.2 cal ka BP and the Hollabåttjønnen Bog (Tønsnes) from 4.3 to 0.7 cal ka BP cal ka BP, and environmental and climatic reconstructions were made from both, based on their modern environmental and climatic preferences. These reconstructions tell a story of fluctuating climatic and environmental conditions throughout the Last Glacial Maximum contrary to previously reported reconstructions of persistent extreme cold. Instead, these results support the side of the debate that the LGM on Andøya was comparatively warm, with chironomid inferred mean July temperatures of 9°C prior to 20.0 cal ka BP. This was followed by a more variable Late Glacial (6.4 - 9.5°C) and a sustained increase in mean July temperatures to between 10 and 11°C during the early Holocene (11.7 - 8.1 cal ka BP), in agreement with other proxies. These reconstructed temperatures do not discount the possibility of other temperate taxa surviving on the island throughout the LGM. Holocene environmental reconstructions indicate that during the early Holocene (10.9 - 8.2 cal ka BP) Ramså was dominated by Sphagnum moss and aquatic species indicate standing water was nearby. These reconstructions confirm those reported from other proxies, but add further information, for example, that the presence of a wetland environment with standing water indicates that the northwest of Andøya probably experienced higher rainfall than the south. Furthermore, the beetles suggest that trees arrived on Andøya between 10.5 and 9.71 cal ka BP, which compliments and agrees with the evidence from other proxies. During the late Holocene at Tønsnes (4.3 - 0.7 cal ka BP) an oligotrophic bog existed, but this was less homogenous with species indicating drier heathland and small groves of trees present throughout. These reconstructions have demonstrated the effectiveness of using chironomids and beetles as palaeoecological proxies within northern Norway, as they support, and add detail to, reconstructions made from other proxies. Nonetheless, temperature reconstructions based on beetles are broad and lack the precision of those inferred from chironomids, likely a reflection of the mutual climatic range method working better in reconstructions from lower latitudes, where the number of stenothermic species recovered is significantly higher. Future studies in the region should concentrate on combining the beetle-inferred July temperatures with those inferred from chironomids, giving multiple lines of evidence, which is more likely to reflect the actual air temperature. This study emphasises the need for further methodological development in northern Norway, and likely across high latitudes, to enable beetle reconstructions to be used to their full potential. Moreover, the results demonstrate that the level of detail that can be gained about the environment from beetles cannot be gained from other proxies, including chironomids and, therefore, confirms that beetles should be an integral part of future palaeoenvironmental studies, alongside other proxies. These findings demonstrate that multi-proxy studies should remain a priority in Quaternary reconstructions, particularly at high latitudes. Furthermore, similarities in the beetle assemblages from the early and late Holocene emphasise the importance of peat bogs as an ecosystem within northern Norway, and therefore should be considered key sites for conservation.

Structural colours arise from the interaction of visible light with nano-structured materials. The occurrence of such structures in nature has been known for over a century, but it is only in the last few decades that the study of natural photonic structures has fully matured due to the advances in imagining techniques and computational modelling. Even though a plethora of different colour-producing architectures in a variety of species has been investigated, a few significant questions are still open: how do these structures develop in living organisms? Does disorder play a functional role in biological photonics? If so, is it possible to say that the optical response of natural disordered photonics has been optimised under evolutionary pressure? And, finally, can we exploit the well-adapted photonic design principles that we observe in Nature to fabricate functional materials with optimised scattering response? In my thesis I try to answer the questions above: I microscopically investigate $\textit{in vivo}$ the growth of a cuticular multilayer, one of the most common colour-producing strategies in nature, in the green beetles $\textit{Gastrophysa viridula}$ showing how the interplay between different materials varies during the various life stages of the beetles; I further investigate two types of disordered photonic structures and their biological role, the random array of spherical air inclusions in the eggshells of the honeyguide $\textit{Prodotiscus regulus}$, a species under unique evolutionary pressure to produce blue eggs, and the anisotropic chitinous network of fibres in the white beetle $\textit{Cyphochilus}$, the whitest low-refractive index material; finally, inspired by these natural designs, I fabricate and study light transport in biocompatible highly-scattering materials.

Degraded DNA can be recovered from specimens that are preserved in museums and the natural environment. Data generated from such DNA have provided valuable evidence for the assessment of a suite of biologically important questions. However, research of this nature is limited for invertebrate taxa, despite their diversity and ecological necessity. Using DNA data from dry-stored museum and permafrost-preserved ancient specimens, this thesis greatly extends the study of degraded DNA from invertebrates. The thesis focuses on two arctic ground beetle species (Amara alpina, Pterostichus brevicornis), which are abundant in museum collections and permafrost deposits. A lack of data that characterises the preservation and potential of degraded beetle DNA, and thereby assessment of future possibilities for this emerging field, provided the impetus for the first three results chapters. Using two different sequencing approaches, the preservation of DNA in museum and ancient specimens was investigated. In addition, the taxonomic utility of DNA extracted from these specimens was assessed. These chapters demonstrate that DNA could be routinely recovered from museum specimens. DNA from ancient specimens could be recovered from A. alpina but not P. brevicornis. In most cases therefore, degraded DNA from these beetles could be used to address further questions. The final two results chapters focus on the response of the two study species to a past period of climatically driven change, using DNA data from museum and ancient specimens. In these chapters, the mode of postglacial colonisation of Canada at the end of the last ice age was investigated. It was found that existing models of this process were broadly, but not wholly, correct. This may have implications for models of how beetles will respond to future climatic change. Although some challenges lie ahead, this thesis demonstrates the potential for museum and ancient permafrost-preserved beetle specimens in future, DNA-based, large-scale investigations.

Immune systems are thought to be costly to maintain and express in a variety of taxa. Evidence for this comes from observations that mechanisms which deal with pathogenic challenge are often extremely variable and are induced in the presence of an immune challenge, rather than being constitutively active. This thesis presents work aimed at testing predictions arising from these ideas, using the mealworm beetle T. molilor (Coleoptera: Tenebrionidae) as a model system. Assays were developed which reflected three specific aspects of immunity (haemocyte count, phenoloxidase levels and resistance to a generalist fungal pathogen), thereby allowing aspects of immune function to be quantified. It was shown that the level of fungal resistance differed in beetles reared gregariously (higher resistance) and solitarily (lower resistance). Conspecifics are a source of disease (Freeland 1983), so this is an example of immune defences being induced in situations with a higher risk of pathogenesis (density dependent prophylaxis). A strong predictor of fungal resistance was the degree of melanisation of the adults' cuticles. This trait was shown to be highly heritable (59%), as was the total haemocyte count of an individual: an important aspect of general invertebrate immunity. Selection for cuticular melanisation resulted in a rapid response, confirming the existence of large amounts of additive genetic variance for this trait. Fungal resistance showed a correlated 111 response to selection for cuticular melanisation, indicating that this too has additive genetic variance. Lines selected for darker cuticles showed higher levels of fungal resistance than those selected for lighter cuticles. Cuticular melanisation and fungal resistance are therefore genetically correlated, and the former can be used as an indicator of the latter in T. molitor. No specific costs of cuticular melanisation or fungal resistance were identified. A correlated response to selection for cuticular melanisation on larval competitive ability was investigated, but no such response was seen. Thus the mechanisms maintaining variability and inducibility in cuticular melanisation and fungal resistance are unknown. This thesis has therefore identified patterns of immune expression consistent with the hypothesis that immunity has associated costs, although these costs have not been shown. It has also identified a potentially novel role for cuticular melanisation, as an indicator of immunity to fungal pathogens.

Slugs are important pests in many agricultural crops and potential biological control agents are being studied as an alternative to molluscicide application. The role of the carabids Pterostichus madidus (Fabricius) and Nebria brevicollis (Fabricius) as predators of the slug Deroceras reticulatum (MUller) was examined in the laboratory. These generalist beetle species were only capable of killing small, healthy slugs (<0.1 ig) as they were unable to overcome the defence mucus production of larger slugs. Dead slugs were scavenged in preference to killing healthy slugs. The relatively high proportion of positive serological results from field caught carabids may reflect a high scavenging rate rather than actual predation on live slugs. Slugs are difficult prey items for generalist beetles to overcome due to their defence mucus production. Results suggest that few slugs will be consumed in the presence of alternative prey which are less difficult for beetles to overcome. Slugs which could no longer produce defence mucus were readily attacked by both beetle species. Although beetles killed few healthy slugs the presence of beetles influenced slug behaviour with slugs of all sizes foraging for shorter periods of time. Any reduction in slug activity on the soil surface would in turn lead to a reduction in seedling damage. The results suggest that the role of potential predators in pest control can only be evaluated fully with a detailed understanding of their behaviour.

281 species of terrestrial ground-living beetles were recorded from 69 riparian and wetland sites in the floodplain of the lowland River Soar, England. Differences in species composition between pitfall trapped and timed hand-collected samples were smaller than those attributable to environmental and seasonal factors. Detrended Correspondence Analysis consistently ranked all sites against seasonal variations between April and June and floodplain sites against annual variations. DCA axis 1 scores were slightly better correlated with important environmental variables at the ecohabitat (<5Om) scale rather than the microhabitat scale. Canonical Correspondence Analysis detected assemblage responses to flooding disturbance and grazing pressure along the main channel as well as to water level stability in the floodplain. A conceptual model of floodplain land-use and river management postulated a dynamic equilibrium between flooding disturbances and vegetational succession, producing geomorphic and vegetational structures which serve as semi-aquatic habitats for terrestrial beetle assemblages with appropriate species traits. Impoundment for navigation affects assemblages by modifying the severity of flooding disturbance. The effects of grazing pressure resemble flooding disturbance. The short-term (< 5yr) impact of bank regrading was explained by differences in severity, predictability and frequency compared to the beetles' generation length. Evenness and species richness were affected only by flooding and grazing disturbance. This response was not predicted by the intermediate disturbance hypothesis because the frequencies of flooding and grazing disturbances in the Soar valley are not appropriate to the hypothesis, which more closely relates to disturbance by bank regrading. In comparison to diversity indices, a rarity index was much less sensitive to environmental factors than species diversity indices and more robust against seasonal and yearly fluctuations. Consequently, it has more potential for use in site quality assessment.

Callosobruchus maculatus and C. analis present an interesting problem to the evolutionary ecologist. The larvae of both species complete their development within the seeds of various legumes such as black-eyed beans. However, the two species compete over the resources within the bean in very different ways. C. maculatus larvae compete in a scramble process; the larvae avoid each other within the bean and several adults can emerge from a single bean. In contrast the larva of C. analis compete actively within the bean, seeking each other out and fighting until only one larva is left alive. As a consequence, only a single C. analis adult will emerge from each bean, no matter how many larvae were initially present. In this thesis I try to determine the types of selective forces that can cause two species to evolve such different competition strategies when competing over similar resources. In Chapter 3 it is suggested that differences in the cost of exploitation competition suffered by the two species could explain why they originally evolved different larval competition strategies, but that these differences are not enough to maintain the strategies under current conditions. It is suggested that historical constraints may have limited C. analis to using an ancestral contest competition strategy that is maladaptive on the large hosts which this species currently uses. In chapter 4 the effect of host size on the cost of exploitation competition is investigated further. As expected, the cost of exploitation competition increases as bean size decreases. In chapter 5 the cost of fighting is measured for C. analis larvae. Although the fitness of a larva that fights over a bean and wins is affected by having fought, the magnitude of the effect is small, and probably of little evolutionary consequence. In chapter 6 a game theory model is presented that investigates the effect of asymmetries in fighting and passive competitive ability on the evolution of competition strategies. The results suggest that such asymmetries will increase the possibility that aggressive competition strategies will evolve and could also explain the conditional strategies used by some strains of C. maculatus. In chapter 7 a genetic model is presented that investigates the effects of population structure on the evolution of competition strategies. The results of the model suggest that the patchy population structure, typical of stored product pests such as Callosobruchus beetles, can favour the evolution of scramble competition strategies. Finally the factors that may affect the competition strategy that a species evolves ~e discussed in more general terms.

Aspects of the distribution and ecology of some surface-dwelling invertebrates were examined on different high-altitude vegetation types in the north Pennines, England. The influence of the boundary between habitats on the invertebrate community was also investigated, and the effects of habitat heterogeneity on invertebrate distribution were discussed. Spiders and carabids were sampled from the dominant vegetation types on the plateaux of three mountain summits (Cross Fell, Littie Dun Fell and Great Dun Fell) in 1991 using pitfall traps. Multivariate methods were used to classify and ordinate the sites based on their fauna and to assess the influence of the local environmental variation on the species distribution. Three spider assemblages were recognised based on their common species composition; two short Festuca grassland assemblages and a Nardus/Eriophorum assemblage associated with greater vegetation density. The results suggest that variation in the vegetation structure is the major factor influencing spider distribution on the summit plateaux, with slope and soil depth also contributing. The carabids appeared too widely distributed to assign to any specific vegetation types. The influence of the interface between different vegetation types on the spider and carabid fauna was sampled using pitfall traps in 1992-3. At the boundary between two highly contrasting habitats (sheep pastures and conifer plantations) an edge effect was found in both groups, where species richness was elevated. The major contribution to this increase was the mixing of both pasture and plantation species, species specific to the interface were few. The edge effect at this interface was narrower but larger in spiders than in carabids. At the boundary between two more similar habitats (grazed and ungrazed upland grassland) the edge effect was much reduced, species richness was not elevated, and the level of overlap between habitats was much wider. Edge permeability, structural similarity and altitude were considered the most important factors for the differences between boundaries studied. It is inferred that in the high altitude invertebrate community most species are widespread crossing boundaries between vegetation types regularly, though some species may have affinities to particular habitats for different aspects of their ecology. The implications that this study has for understanding the effects and impacts of habitat heterogeneity at the landscape level are discussed, such as invertebrate movement patterns, population dynamics and management aspects.

The potential of insects for forensic investigations has been known for more than 700 years. However, arthropods such as mites could also play a role in these investigations. The information obtained from insects, together with their phoretic mites, is of special interest in terms of estimating the time and geographical location of death. This paper presents the first interaction network between phoretic mites and their host insects in Navarra. It also reports the first time that an interaction network was applied to animal remains of forensic relevance. The data reveal the degrees of specificity of the interactions established, the biological and ecological characteristics of the mites at the time of association, and factors that played important roles in the mites' dispersion. Fauna was collected using 657 traps baited with 20 g of pig carrion over a year. Only 0.6% of insects collected carried phoretic mites. The network comprised 312 insects (275 beetles, 37 flies) and 1533 mites and was analyzed using various packages of the R programming language. We contribute new host insect records for 15 mites, 3 new records of insects as hosts, 5 new mite records for the Iberian Peninsula, and 2 new mites records and 8 new insect records for Navarra.

The diversity of life on earth is breathtaking; a kaleidoscope of shapes, colors, and forms. While vast and varied, this array of complex morphology each follows a similar evolutionary path or story. Any given structure i) arises during evolution (the origin of morphological novelty), ii) diversifies (the diversification of morphology), and then iii) serves some functional role for the organism (the functional significance of morphology). Understanding the mechanistic basis underlying these three components of the evolutionary story has been one of the main foci of biology for centuries. Although the choice of morphological features on which to study this story are nearly endless, the wings of insects offer a powerful opportunity because i) the origins of insect wings are currently unknown, ii) insect wings are highly diverse among the insects (both between and within species), and iii) insect wing structures, and the many benefits they provide, have been critical to massive evolutionary success of insects. This dissertation addresses these three aspects of the evolutionary story, using the unique wings and wing-related structures of a coleopteran (beetle) species, Tribolium castaneum, as a model.In the first study, I examined the origins of insect wings using a wing-related structure (a wing serial homolog) called the gin-trap. By examining the gin-trap, and what occurs when this structure is genetically transformed into a more “typical” wing, I have further supported the dual wing origin hypothesis, a hypothesis that attempts to synthesize and unite decades of wing origin debates. In the second and third study, I used the unique wing structures of beetles, called elytra, to investigate the molecular mechanisms underlying insect wing diversity. In these two studies, I focused on unique experimental approaches, and have thus provided a more comprehensive view of the diversification mechanisms. And in the fourth study, I used elytra to demonstrate the evolutionary importance of these modified wings by empirically determining that they act to protecting beetles from harsh environmental stresses. Combined, these studies have contributed to our understanding of the evolutionary story of insect wings, a story which exists for all the diverse morphology found on this planet.

Predaceous diving beetles (Dytiscidae) are common inhabitants of both lentic and lotic freshwater systems worldwide. They have played a major role in our understanding of the relationship between habitat stability and evolution for dispersal propensity.Numerous endemic diving beetles can be found in on the island of New Guinea. However, like most micro-fauna on remote islands, their evolutionary history and population ecology is largely unknown. In this series of studies, I use both traditional Sanger sequencing and next- generation sequencing techniques to explore the phylogenetic relationship of beetles in a genus as well as the population genetic patterns within a species.

Abdominal pumping is a well-known behavior in insects, thought to function largely in respiratory processes. In particular, the abdominal pump is considered to produce ventilation of air in the tracheal system, but the mechanistic link between abdominal movement and flow of air is not well understood. In this thesis, we explore the relationship between the abdominal pump and ventilation of air using pupal and adult forms of the darkling beetle Zophobas morio. First, we investigated the mechanical linkage between abdominal pumping and active ventilation in pupae by simultaneously measuring abdominal movement, hemolymph pressure, CO2 emission, and deformation of tracheal tubes. This study revealed that pupae with low metabolic rates do indeed exhibit tracheal compression, which is coincident with abdominal pumping and pressure pulsation. However, more than 63% of the abdominal pumps and associated pressure pulsations did not lead to tracheal compression. This result can be explained by the status of the spiracles; when the system is closed, little compression in the tracheae can occur. Therefore, we conclude that abdominal pumping in insects does not necessarily lead to ventilation and may serve other functions, such as producing hemolymph flow for circulation. Insects have an open circulatory system, with flow driven largely by the small dorsal vessel. Within the open coelom, hemolymph pressure should be mostly uniform, suggesting that abdominal pumping does not produce hemolymph flows within the main body cavity. We tested this assumption by simultaneously measuring hemolymph pressure in different locations in the coelom. Within the abdomen and thorax, hemolymph pressure is nearly uniform, as expected. However, hemolymph pressures are significantly different between the abdomen and thorax. This suggests that the coelom is compartmentalized, and that abdominal pumping can induce hemolymph flow within the coelom. Throughout these experiments, we faced a common difficulty inherent to flow-through respirometry systems: they are incapable of providing direct, instantaneous measurement of gas concentration. Previous methods are not able to reconstitute the rapid dynamical changes in respiratory signals that are required for precise temporal analysis. Therefore, we developed two new methods to accurately recover instantaneous gas exchange signals, based on new models of the impulse response of the system. These methods enabled us to accurately recover fast- changing respiratory signals with a higher fidelity than previously possible. Using these methods, we demonstrate the synchronization of respiratory data with other physiologically relevant signals, such as pressure and abdominal movement. This research was supported by NSF grant #0938047 and the Virginia Tech Institute for Critical Technology and Applied Science (ICTAS).

Some tenebrionind beetles inhabiting the Namib desert are known for using their body to collect water droplets from wind-blown fogs. We aim to determine whether dew water collection is also possible for desert insects. For this purpose, we investigated the infra-red emissivity, and the wetting and structural properties, of the surface of the elytra of a preserved specimen of Physasterna cribripes (Tenebrionidæ) beetle, where the macro-structure appears as a series of “bumps”, with “valleys” between them. Dew formation experiments were carried out in a condensation chamber. The surface properties (infra-red emissivity, wetting properties) were dominated by the wax at the elytra surface and, to a lower extent, its micro-structure. We performed scanning electron microscope on histological sections and determined the infra-red emissivity using a scanning pyrometer. The emissivity measured (0.95 ± 0.07 between 8–14 μm) was close to the black body value. Dew formation occurred on the insect’s elytra, which can be explained by these surface properties. From the surface coverage of the condensed drops it was found that dew forms primarily in the valleys between the bumps. The difference in droplet nucleation rate between bumps and valleys can be attributed to the hexagonal microstructure on the surface of the valleys, whereas the surface of the bumps is smooth. The drops can slide when they reach a critical size, and be collected at the insect’s mouth.

Abstract: I assessed deadwood-associated (i.e., ‘saproxylic’) beetles (Coleoptera) along a decay gradient of trembling aspen in mature deciduous stands of the boreal mixedwood forest in NW Alberta. Various collection methods were employed to sample saproxylic beetle species. Assemblages differed between host substrate types and decay classes. Many species were also associated with moss presence and percent bark cover. Although small (7 to 15.9 cm) diameter logs were most abundant in the stands, most indicator species were associated with logs ≥25 cm in diameter. Samples of saproxylic beetles varied greatly depending on collection method; however window trap captures were compositionally similar regardless of their placement (on snags or freely-hanging). This suggests that window traps are less appropriate for assessing small-scale habitat associations. Deadwood associations revealed here indicate that a wide range of substrate types, decay classes, and sizes are important features of saproxylic beetle habitats that should be retained for biodiversity conservation.

The small hive beetle (SHB), Aethina tumida Murray, was first detected in Australia in 2002. Since then it has become a major pest of bee hives, spreading rapidly throughout the eastern mainland states. When conditions are suitable, beetles lay their eggs within bee hives and honey sheds, often in the combs, either in the hive or in stored honey combs pre- or post-extraction. Hatching larvae then feed on the honey, pollen, bee eggs, bee larvae and brood. The resulting contamination of the honey renders it useless for extraction, thereby leaving beekeepers bereft of their main source of income from the hives. Beekeepers also face the cost of cleaning contaminated supers and hives and restoring colonies to full strength or even replacing colonies following heavy infestations. A number of strategies to minimise the impact of SHB are already in use in Australia, and include trapping devices, insecticide delivery mechanisms, modifications to hive designs, improved beekeeping techniques and hygienic procedures. However, SHB continues to cause large-scale economic losses within the industry. It is clear that a better understanding of the biology of the SHB is required if beekeepers are to effectively manage this pest using a sustainable, integrated approach. This project sought to elucidate a number of biological and behavioural characteristics of SHB that directly relate to damage in hives and honey houses. The research was aimed at generating data that would support and enhance the effectiveness of existing SHB control strategies as well as provide the basis for new strategies, for the commercial and amateur beekeeping industry.

Insects are well recognised as being the major contributor to global biodiversity, and for their critical involvement in many biotic interactions. Most of the insect diversity is found in tropical rainforests. However, these forests are threatened by high rates of clearing and the subsequent fragmentation of remaining habitat. The effects on biota, particularly insects, are poorly understood as are the mechanisms mediating faunal changes. Reforestation could potentially alleviate some of the deleterious effects of forest loss and fragmentation. However, because reforestation is a relatively new endeavour, it is little known just how much insect biodiversity can be supported by reforestation and what factors influence insect colonisation. These issues were investigated in the Atherton Tablelands of north-eastern Australia, a landscape whose rainforest has been heavily cleared and fragmented over the last 80 years, but is also the focus of reforestation efforts. To quantify the effects of rainforest loss and fragmentation, pasture sites were compared with small rainforest fragments, and with the edges and interiors of large rainforest fragments (24 sites in total). Sites with replanted rainforest (planted with a high diversity of plants) were also included. These varied in their age (2-17 yrs) and their distance (0-4.5 km) from existing rainforest (24 sites in total). Another set of reforested sites was also studied but these differed in their planting style (number of plant species, spacing etc). This second set of sites was located in two regions: the Atherton Tablelands (50 sites), and in the subtropics of eastern Australia (54 sites). At each site, beetle assemblages were surveyed using methods that sample beetles near the ground (four ground-based flight interception traps in the first set of sites and ten pitfall traps in the second set of sites), and then the assemblages among site-types were compared. Over 32,000 beetles were caught and identified to the level of family, and of these, 15,206 were identified further to the level of species. Very few beetle species were present in pasture, suggesting that converting rainforest into pasture has a very strong negative effect on beetle diversity and species composition. Irrespective of rainforest fragment size, beetle species composition in drier rainforest habitats was different from that of moister rainforest. Beetle species composition also differed between small remnants and interior rainforest: drier-associated species were more abundant in small remnants, whereas wetter-associated species were more abundant in interiors. This pattern can be best attributed to a fragmentation effect mediated by differences in microclimate. With the exception of differences between rainforest and pasture, these results were generally not observed among beetle assemblages identified to coarser taxonomic groups (family, feeding guild, and body size). Among replanted rainforest, older sites and those adjacent to rainforest had a more rainforest-like beetle species composition. However, even the closer and older sites had a substantially lower abundance and richness of rainforest-associated beetles than did rainforest. Age effects were generally stronger than distance effects. Beetle assemblage similarity to rainforest was more strongly correlated with structural similarity to rainforest than with site age or distance from rainforest. Thus the use of revegetation techniques which lead to more rainforest-like structural conditions appears to be of over-riding importance in catalysing the rapid acquisition of rainforest beetle assemblages in the initial stages of restoration. Nevertheless, not all beetle species were equally affected by the factors tested. Large-bodied beetle species (>5 mm) were more strongly influenced by distance than small-bodied species (

A study of the biology of Tropisternus lateralis, a hydrophilid beetle, was conducted during the flood period of a single playa on the Southern High Plains of Texas from early June 1995 through early September 1995. Mechanism of colonization, tolerance/avoidance to drought, larval density, and secondary production were analyzed. T. lateralis colonized playas from surrounding aquatic habitats and avoided drought through aerial dispersion. Once in the playa, larval density increased over time. Secondary production was 1.31 g/m2/.25 yr. In addition, aquatic Coleoptera diversity was studied in seven playas on the Southern High Plains of Texas. A total of twenty three species were identified from the study region. Nine species not reported in playa literature were identified.

Abstract: Masters thesis resulting from an investigation of the natural history of microsympatric species of Agonum (Europhilus) inhabiting entrophie marshes in the George Lake area of central Alberta.

Abstract: Doctoral thesis. Systematic study of the carabid beetle genus Nebria.

Two highly organic sediment sequences from central and western Illinois (the Athens North Quarry and Biggsville sites, respectively) of Middle and Late Wisconsinan age were studied to gain knowledge about the environment and climate of this area during the time immediately prior to the maximum extent of the last glaciation. Paleoenvironmental and paleoclimatic inferences are based principally upon knowledge of the habitat preferences and geographic distributions of extant species of beetles that are represented as fossils. These data are supplemented by information from sedimentological and taphonomic studies and from previously published palynological and plant-macrofossil studies. The Athens North Quarry site is a 2.8 m-thick sequence of organic silt, ranging in age from about 25,000 to 22,000 11 c yr B.P. Two faunal zones based upon beetle fossils were recognized; a third was defined using gastropods. The environment, inferred from the fauna, was the margin of a eutrophic lake surrounded by a moist coniferous forest. The sequence of events at the Athens North Quarry site began with the expansion of a nearby lake or pond over the forest floor, and ended with the infilling of the water body by Woodfordian loess and organic material. The Biggsville site is a channel-fill deposit consisting of fluvial deposits, organic sediments, peat, and loess. Samples for beetle analysis were collected from a 2.2 m-thick section of organic loams and peat ranging in age from 27,870 ~ 290 to 21,410 ~ 290 ~Cyr B.P. Two coleopteran faunal zones were recognized. Habitats inferred from the beetle species present in these zones are interpreted as representing the development and demise of a bog in an abandoned stream channel, surrounded by a thin, spruce-dominated coniferous forest. The bog and forest were eventually choked by peat and loess deposits. This was followed by a period of pedogenesis. An interpretation of the climate of central and western Illinois between about 28,000 and 21,000 14c yr B.P. is based upon the present ranges of the species represented by fossils in the Athens North Quarry and Biggsville sites. The majority of these species now occur in the southern boreal forest region of southern Canada and northern United States. The climate during this period apparently was relatively stable, in contrast to the interpretation of previous workers in this area; compositional changes in the coleopteran assemblages are interpreted as reflections of local changes in the environment rather than as indications of the shift from interstadial to full glacial conditions.

The endemic Scarabaeid genus Pyronota boisduval contains small usually green beetles of diurnal habit commonly found on Leptospermum sp. bushes in the summer; hence their common name: Manuka beetles. The name Pyronota is derived from the Greek πυpos produced by fire or heat and ѵoτos tergum and refers to the metallic iridescent appearance of the dorsum. The genus has been revised by Given (1952) but no previous detailed studies of the biology and ecology of any species have been made. The aim of this study has been; first to review and revise past taxonomic work on the genus, wherever possible advancing knowledge of species to the level of gamma taxonomy; second to study and where possible compare some aspects of the biology and ecology of the three common and widely distributed species of the genus, Pyronota festiva (Fabr.), P. laeta (Fabr.), P. edwardsi Sharp. The two aspects of this work have been complementary. A full appreciation of the taxonomic status of the species under study could not have been realised without a knowledge of their behaviour in life as biological entities.

Abstract: Doctoral thesis covering North and Middle American species.