Spider wasps are solitary parasitoids that use one spider to lay a single egg. Even though their behavior seems homogeneous, the features pertaining to nesting and hunting behavior are diverse for different species. There are approximately 5,000 described species, in 120 genera, but there are probably many undescribed species. The systematics of Pompilidae has been studied in recent years, but only morphological data have been used for this purpose. Because of the morphological homogeneity of spider wasps, molecular data may prove promising for understanding the systematics of the group. Furthermore, dated molecular phylogenies calibrated with fossil data may allow studying the historical biogeography and evolution of the group. I used the nuclear molecular markers elongation factor–1 α F2 copy (EF1), long–wavelength rhodopsin (LWRh), wingless (Wg), RNA polymerase II (Pol2), the D2–D3 regions of the 28S ribosomal RNA (28S), and the mitochondrial Cytochrome C Oxidase I (COI) in a Bayesian and Maximum Likelihood framework, to reconstruct the phylogenies of four main Pompilidae groups: the subfamily Pompilinae, the tribe Aporini, the genus Psorthaspis, and the genus Drepanaporus. I also studied the fossil Pompilidae, and used those results to produce time-calibrated phylogenies of Pompilinae, Aporini, and Psorthaspis. Molecular phylogenetic results support the utility of the use of molecular markers for species delimitation and sex-associations in Pompilidae. In addition, the use of dated phylogenies supports the correlation of host use with diversification rate-shifts, the coevolution of mimicry between pompilids and velvet ants, and various biogeographical hypotheses never tested before for spider wasps.

<p>Vår tids syn på teknik ser vi tydliga spår av i dagens filmer, och kanske framförallt superhjältefilmer. Där använder sig både hjältar och skurkar av avancerad teknik i sin kamp mot varandra. Men även synen på biologi avspeglas i dessa filmer, och det mest intressanta är när dessa ställs mot varandra. Vi har jämfört två av vår tids största hjältar, en som använder sig av teknik och en som har biologiska krafter, för att se vilka likheter och skillnader som finns. Hjältarna det rör sig om är Spider-Man och Batman.</p>

We identified and evaluated a phytoseiid predator as a biological control agent of multiple spider mites pests that occur in ornamental nurseries. When comparing species, Neoseiulus fallacis (Garman) had a wider prey range than Galendromus occidentalis (Nesbitt), a higher probability of overwintering than Neoseiulus califomicus McGregor and was equally or more effective at suppressing spider mites than either of the other 2 phytoseiids in 4 field tests. To further evaluate N. fallacis we 1) measured prey range when held with 29 ornamental pests or alternative foods under laboratory conditions, 2) tested biological control of spider mites on representative plant species at both small and large spatial scales, 3) developed release and conservation strategies of the predator, and 4) examined the efficacy of the predator in controlling recently introduced pests. Neoseiulus fallacis had greatest survival and reproduction when feeding on spider mites but eriophyid mites, other mites and pollen enhanced survivorship and, in some cases, reproduction. When inoculated into ornamental plants, spider mite suppression was "acceptable" in 81% of small scale tests and-in all large scale tests. Limitations in control occurred in tall, vertical growing plants with little foliar canopy. Inoculation of N. fallacis at low prey densities into apple rootstocks was successful at suppressing Tetranychus urticae Koch and similar to control achieved at moderate prey densities. In small scale banker plant studies, high densities of adult and immature mites of N. fallacis were produced and moved downwind to receiver plants. In field tests with receiver plants placed at greater distances, only N. fallacis adult females readily dispersed to 30 m or more. When comparing overwintering survival of adult females among plant types, N. fallacis survived most on conifers, intermediate on evergreen shrubs and least on herbaceous perennials, deciduous shrubs and shade trees. Covering plants with protective plastic reduced overwintering survival of the predator. Neoseiulus fallacis successfully suppressed the newly introduced pests Panonychus citri (McGregor) and Schizotetranychus celarius (Banks) on Skimmia japonica Thunberg and Sasaella hidaensis (Makino and Uchida), respectively. Initial studies suggest that N. fallacis can be an effective biological control agent of multiple spider mites in low-growing and selected higher-growing ornamental plants. / Graduation date: 2000

The life history, temperature, humidity, and feeding requirements of the phytoseiid predator mite, Typhlodromus americanus Chant and Yoshida-Shaul were tested in the laboratory. Occurance of the mite in the field during different times of the year was investigated as well. Effects of temperature and humidity on egg hatch, the feeding requirements of the larvae, the amount consumed by each life stage, the length of each life stage and suitability of different food sources were investigated in the laboratory. The use of the mite as a biological control agent was evaluated by using the information gained from the laboratory experiments. T. americanus was originally discovered in plantation grown Douglas-fir in western Oregon. Since that time the mite has been found on a number of other hosts throughout North America. The mite is active year round in the Christmas tree plantations of the Willamette Valley in Oregon. The adult is found in or near the one year old bud scars and the eggs are typically deposited there also. Life parameters were measured providing a net reproductive rate of 4.23, a mean generation time of 24.45 days, and an intrinsic rate of increase of 0.059 The intrinsic rate of increase was low when compared to other predator mites and numerical response to prey increase would not be possible with such a low rate. The optimal temperature for the shortest eclosion time (54.4 hr.) and the highest survival (96.4%) was 26��C. The regression of temperature vs. time to hatch gave a 90% R�� with both the slope and intercept significantly different from zero. Humidities above 70% had survival rates over 96% and eclosion rates in the range of 50-58 hours. The relative humidity at which 50% of the population died was 58.6%. The mite was found to feed readily on the pest mite Oligonychus ununguis (spruce spider mite), as well as Tetranychus urticae (two spotted spider mite), and corn, oak, and Douglas-fir pollens. The larval form of the predator mite does not require food to molt to the protonymph, but the protonymph does require food to molt. If water is provided the entire time from egg to death, the protonymph can survive about ten days. Females consumed more Tet. urticae than males in both the immature and adult stages. The T. americanus that were fed corn pollen and Tet. urticae (complete diet) lived for over 115 days. Mites raised on oak and corn pollens did not survive as long (only 70-80 days), and those raised on Douglas-fir pollens did not reach adulthood. Egg production was observed on the complete diet, but not on the diets of pollen. The largest number of eggs were laid around the twelfth day after the molt to adult. Control and management of field conditions to improve habitat for T. americanus will be the best approach for its use as a biological control agent. As it does not respond numerically to prey increase, it will be more effective in a regulatory role to prevent these increases while the prey is at low levels. / Graduation date: 1996

<p>Quantum sl_3 projectors are morphisms in Kuperberg's sl_3 spider, a diagrammatically defined category equivalent to the full pivotal subcategory of the category of (type 1) finite-dimensional representations of the quantum group U_q (sl_3 ) generated by the defining representation, which correspond to projection onto (and then inclusion from) the highest weight irreducible summand. These morphisms are interesting from a topological viewpoint as they allow the combinatorial formulation of the sl_3 tangle invariant (in which tangle components are labelled by the defining representation) to be extended to a combinatorial formulation of the invariant in which components are labelled by arbitrary finite-dimensional irreducible representations. They also allow for a combinatorial description of the SU(3) Witten-Reshetikhin-Turaev 3-manifold invariant. </p><p>There exists a categorification of the sl_3 spider, due to Morrison and Nieh, which is the natural setting for Khovanov's sl_3 link homology theory and its extension to tangles. An obvious question is whether there exist objects in this categorification which categorify the sl_3 projectors. </p><p>In this dissertation, we show that there indeed exist such "categorified projectors," constructing them as the stable limit of the complexes assigned to k-twist torus braids (suitably shifted). These complexes satisfy categorified versions of the defining relations of the (decategorified) sl_3 projectors and map to them upon taking the Grothendieck group. We use these categorified projectors to extend sl_3 Khovanov homology to a homology theory for framed links with components labeled by arbitrary finite-dimensional irreducible representations of sl_3 .</p> / Dissertation

The ultrafast optical regime is defined, as it applies to laser pulses, along with a brief introduction to pulse generation and characterisation technologies. A more extensive description of our particular amplified pulse generation and SPIDER characterisation systems follows. Data verifying the correct operation of the characterisation system is presented and interpreted. Our laser system is then characterised in two different configurations. In each case, the data describing the system is presented and analyzed. Conclusions are made regarding the performance of both the characterisation and laser systems, along with suggested improvements for each.

The ultrafast optical regime is defined, as it applies to laser pulses, along with a brief introduction to pulse generation and characterisation technologies. A more extensive description of our particular amplified pulse generation and SPIDER characterisation systems follows. Data verifying the correct operation of the characterisation system is presented and interpreted. Our laser system is then characterised in two different configurations. In each case, the data describing the system is presented and analyzed. Conclusions are made regarding the performance of both the characterisation and laser systems, along with suggested improvements for each.

Venoms of the Sicariidae spider family contain phospholipase D (PLD) enzyme toxins that can cause severe dermonecrosis and even death in humans. PLD toxins are known to cleave the substrates sphingomyelin (SM) and lysophosphatidylcholine (LPC) in mammalian tissues, releasing a choline headgroup and a reported monoester phospholipid formed via a hydrolytic reaction. However, some PLD toxins have demonstrated the ability to utilize substrates besides SM and LPC and other PLD toxins have demonstrated no activity against either SM or LPC. Given that the etiology of the disease state following envenomation is not well understood, we postulated that PLD toxins could be utilizing other phospholipid substrates in vivo. To determine the level of promiscuity among the PLD toxins, we developed a novel ³¹P-NMR assay to measure phospholipase activity against a panel of potential phospholipid substrates. While developing the assay, we made the surprising discovery that recombinant PLD toxins, as well as whole venoms from diverse Sicariidae species, exclusively generates cyclic phosphate rather than hydrolytic products. We also found that a distantly related PLD toxin from a pathogenic bacterium, with low sequence identity to the spider PLDs, exclusively generates cyclic phosphate products. We then established that St_βIB1i, a PLD with extremely diminished activity toward SM and LPC, actually demonstrates large preferential specificity towards ethanolamine phospholipid substrates. We solved the crystal structure of St_βIB1i to compare to PLD toxins of known structure, toward an understanding of the molecular basis of substrate specificity. The cyclic phosphate products generated by the PLD toxins have extremely different biochemical properties than their monoester counterparts and may be relevant to the pathology following envenomation or bacterial infection. In addition the specificity St_βIB1i has for ethanolamine substrates may have biological implications, as insects have high concentrations of ethanolamine-containing phospholipids.

This thesis uses multiscale computational modelling to find the fundamental principles that govern defects forming during the operation of new electro-optical devices and the processing of spider silk fibers. The generalized approach developed in this thesis bridges engineering devices and biological processes based on liquid crystalline materials. / Three types of defects are encountered: inversion walls, lines and points. Inversion wall defects are found in the electro-optical device when a nematic thin film undergoes a temperature-induced surface anchoring transition. Point defects naturally occur in the tubular extrusion duct of spiders, while line defects present close topological connections with point defects and are widespread in many high-performance industrial fibers. Three models are used in this thesis and their usage is dependent on the characteristics of the defects studied. / In the case of inversion wall defects, computational modelling is used to verify, complement and analyze experimental measurements made with fluorescence confocal polarizing microscopy by our collaborator at the Georgia Institute of Technology. The various simulation results agree and explain very well experimental observations and provide a thorough understanding of the wall defects behavior. A computational technique is developed to enable the precise determination of the interaction between the liquid crystal and the device substrate. Understanding the behavior of wall defects and estimating interfacial properties are indispensable to the development and optimization of the electro-optical device as they affect properties like temperature of operation, switching voltages and response time. / Computational modelling is also used to investigate the behavior of nematic point defects confined in cylindrical cavities as observed along spiders' spinning apparatus, and to examined textural connections with other well know structures seen in industrial fibers. The various scenarios investigated include: interactions between point defects, topological transformations between point, line and ring defects as well as interactions between ring defects. The simulation results agree and complement previous investigations but also offer a new fundamental understanding on the nature and stability of defects in cylindrical cavities. Understanding the behavior of nematic point and line defects in cylindrical geometries is important as they play a fundamental role in the processing of natural and industrial high-performance fibers.

Stegodyphus mimosarum Pavesi,1883 and S. dumicola Pocock, 1898 are two species of philopatric, inbred, permanently communal, non-territorial spiders that co-occur in parts of South Africa. The patchiness of colony distribution, limited dispersal capabilities and the observation of periodic, but rare mass dispersal events raised interest in factors influencing dispersal. The aim of this project was firstly, to determine which factors influence the spiders' readiness to leave a colony (two laboratory experiments), and secondly, to map nest dispersion in Weenen Nature Reserve, Kwa-Zulu Natal, and to use this to explain nest distribution. The first experiment assessed whether group size and variance in access to resources influenced the decision to disperse. Four colony sizes (8, 16,32 and 64) of S. mimosarum were established under a proportional feeding regime. I expected more spiders to leave larger colonies due to intra-group competition. However, there was no significant increase in the number of spiders leaving with increasing group size. Significantly more spiders left a colony during spring and when spiders were large. In the second experiment, I assessed whether the mean amount of food available, in liberally fed or starved colonies influenced the decision to disperse. Five colonies were fed daily on an abundance of prey items and five were starved. I expected more spiders to leave the starved colonies. However, a significant number of spiders left colonies where food was abundant. During a field survey nests were tagged within 40 plots of 50 m radius, and randomly. Retreat dimensions, height above ground, nest position, nearest neighbouring nests, and species were recorded. Nest status was tracked over six months to three years. I confirmed that nest height above ground was significantly higher for S. mimosarum. The two species differed in retreat volume and nearest neighbour distances. Most nests occurred on the northern aspect of trees. Few nests survived beyond three years, although many new nests were established. Access to resources influenced the decision to disperse. However, only well-fed (larger) spiders had the resources to relocate. Patchy nest distribution could be a consequence of nest site selection, short distance dispersal by budding and bridging, and long distance dispersal by ballooning. / Thesis (M.Sc.)-University of Natal, Durban, 2002.