Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Entomology." Includes bibliographical references (p. 108-123).

Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Entomology." Includes bibliographical references (p. 34-40).

Thesis (M.S.)--Oklahoma State University, 2009. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--Bryn Mawr. / Recto of pl. i-viii contains letterpress descriptive of the plate following. Reprinted from the Journal of experimental zoology, vol. iv, no. 4. "Bibliography": p. 509-512.

Thesis (M.S.)--Florida State University, 2002. / Advisor: Dr. Walter R. Tschinkel, Florida State University, Department of Biological Science. Title and description from dissertation home page (viewed Sept. 23, 2003). Includes bibliographical references.

Lipoproteins, protein-lipid complexes that have a polar exterior and a non-polar interior, have been found in many vertebrate and insect species, and their basic structure and function appear to be conserved. They facilitate the intercellular transport of hydrophobic lipids through aqueous media. Their synthesis requires an unusual process referred to as lipidation, whereby lipids are added to the protein component of the lipoprotein. Lipidation is thought to occur during or immediately following translation of these proteins, but how this process occurs is unknown. Of particular interest is the extent to which the protein sequence of the apoproteins drives lipidation and the level of involvement of other proteins in this process. In this project, lipidation was studied by expressing the apolipoproteins from the tobacco hornworm, Manduca sexta, in two different expression systems. The first used budding yeast, Saccharomyces cerevisiae , to both determine the ability of unicellular organisms to produce lipoproteins and examine the role that the known secretory pathway for soluble proteins plays in lipoprotein biosynthesis. The second used Drosophila Schneider 2 cells to begin to examine the apolipoprotein sequence for regions that are crucial to lipoprotein biosynthesis. The yeast expression system revealed that unicellular organisms are capable of expressing, lipidating, and secreting M. sexta apolipoproteins. This is first demonstration of any apolipoprotein being expressed in a unicellular organism, and represents a major finding, as unicellular organisms have no need for a particle that functions in intercellular transport. A second major finding in this project is that lipophorin production occurs in the absence of the full apoLp-I sequence. This finding was true for both expression systems, and indicates that the lipidation code resides within the first 45% of the precursor protein sequence. Furthermore, deletion analysis has revealed that removal of any portion of the apoLp-II sequence prevents expression of the apolipoprotein. Taken together, these experiments indicate that all of the information required to make a lipoprotein is included in the apoLp-II sequence.

This thesis addresses the potential of archaeoentomology for reconstructing rural life-ways and the processes of modernisation and the implementation of ‘improvement’ ideas in 19th- and early 20th-century Iceland. Previous archaeoentomological research employed insect remains to reconstruct activity areas, domestic practices and aspects of past living conditions in Icelandic turf farmhouses. However, as there is a lack of comparative modern and ethnoarchaeological data from analogous buildings, the ecological requirements of insect taxa exploiting indoor habitats and the processes by which they may become incorporated in the archaeological record are still poorly understood. To address this lacuna, this thesis presents two studies – a modern analogues study and an ethnoarchaeological one – aimed specifically at testing the potential and limitations of archaeoentomology in the Icelandic context. These studies provide an analytical framework for the reconstruction of life-ways and living conditions on two 19th- and early 20th-century Icelandic sites: Hornbrekka and Vatnsfjörður. These case studies also explore how insect remains may help to improve our understanding of the social and economic changes involved in the modernisation of daily life in rural Iceland. The modern analogues study includes a survey of live and dead insect faunas from farm buildings – animal houses, hay barns and eiderdown workshops – combined with the systematic recording of local environmental and material conditions in the sampling locations. The study refines our understanding of the ecological preferences and tolerances of synanthropic beetles exploiting microhabitats in stable manure and stored hay and identifies duck fleas as potential archaeoentomological indicators of eiderdown processing and storage areas. This dissertation also includes an analysis of insect remains preserved in floor layers in recently abandoned, extant 19th- and 20th-century turf buildings at the farm of Þverá, in Laxárdalur, northeast Iceland, where details regarding the rooms’ functions and cleaning and maintenance practices are known. This study clarifies some of the taphonomic processes involved in the formation of archaeological floors and archaeoentomological assemblages, while also highlighting difficulties related to the identification of resources such as peat, turf and hay using outdoor insects. It also reveals subtle variations between synanthropic communities and ectoparasites recovered from human living quarters, storage areas and animal stalls. Archaeoentomological analyses were applied to the investigation of past activities and living conditions on the 19th- and early 20th-century archaeological sites of Hornbrekka, in northern Iceland, and Vatnsfjörður, in northwest Iceland. Insect remains from Hornbrekka support the previous archaeological interpretations regarding the functions of the excavated rooms and provide new information regarding past activities on the site, including cleaning and floor maintenance practices, participation in trade, and local resource exploitation. At Vatnsfjörður, archaeoentomological assemblages help identify a room’s function as a storage room for animal products, including eiderdown. They also provide supporting evidence for the use of materials from byre and habitation floors as manure in the fields. The archaeoentomological evidence obtained from these 19th- and early 20th-century sites suggest that insect remains have the potential to contribute to a clarification of the processes by which Icelandic rural life-ways came to be modernised.

<p> In this dissertation, the adaptive properties of photoreceptors and their post-synaptic large monopolar cells (LMCs) in the fly's compound eyes are studied. Visual stimuli consisting of time varying square wave and natural light intensities with large modulations in the mean light intensity and small fluctuations around the mean were presented in a single LED to the fly. In the square wave experiment, the light intensity is switched between two levels. The effect of changing intensity levels and switching frequency of transition on photoreceptor and LMC's response is discussed. Time varying light intensities recorded from a natural environment were used in the natural light experiment. The light sequence was displayed respectively at three different speeds; a factor of two faster, equal and a factor of two slower relative to the original speed. The effect of the spatiotemporal correlation and large modulations in the natural light intensities on adaptation is discussed. In addition, experiments with seven LEDs were conducted to determine whether lateral connections from neighboring LMCs change the adaptation state. The frequency analysis of response however breaks down at large intensity modulations, because the system is driven away from its stationary state. In this regime, the response of the system is characterized using the method of generalized eigenvalues, which allows for time domain analysis of non-stationary systems. Before apply this method to the non-stationary system, it was applied to stationary system and compared with frequency analysis to verify the effectiveness of this method. Further, relevant parameters such as effective photon rate and information rate that characterize the different states of adaptation of the non-stationary system were calculated by generalized eigenvalues.</p>

Choosing where offspring will develop is especially important for insects whose larval stages are restricted to a particular host resource. In such insects, maternal egg laying decisions may not only involve choosing optimal hosts based on their intrinsic qualities but also avoiding hosts occupied by conspecific brood. The ability to discriminate between previously exploited and unexploited hosts is often mediated by the use of a marking pheromone. Despite engaging in what appears to be host-marking behavior, the walnut fly Rhagoletis juglandis prefers to deposit clutches into previously exploited hosts. In this dissertation, I quantified host reuse in R. juglandis and assessed its impacts on offspring fitness. I also explored the role that marking pheromone plays in level of reuse. Host reuse by the walnut fly was common in the field, where trees were synchronously infested over a 14-17 day period. It was not unusual for individual fruit to bear 40-80 eggs; given that females laid clutches of ca. 16 eggs, each oviposition puncture probably contained ca. 1.6 clutches. The overall number of eggs deposited into fruit was positively correlated with fruit volume. Field and laboratory experiments showed that increases in larval densities within fruit reduced larval survival and pupal weight, the latter being strongly correlated with the number of eggs a female produced over her lifetime. The temporal staggering of clutches strongly and negatively impacted survival of later clutches. The effect of spatial patterning of clutches on offspring fitness depended on the number of clutches in the fruit: at higher densities, clutches performed better when deposited into the same puncture than when distributed uniformly over fruit. The evidence taken together suggests that host reuse by the walnut fly, R. juglandis, reduces per capita offspring fitness. Consistent with this inference was a final set of observations on female host-marking behavior. In field-cage experiments, fruit that were marked by females for longer durations were less acceptable to other females. Moreover, the duration of time that a female marked a fruit was positively correlated with the size of her clutch. These results indicate that, while females commonly reuse fruit, they nevertheless signal the level of larval competition associated with a fruit and adjust allocation of eggs to fruit accordingly.

Although there is much information about insect associative learning, less is known about the underlying neural mechanisms. This is partly due to the lack of behavioral paradigms providing a suitable model for studying learning mechanisms at the level of individual neurons. This thesis describes the background to, and the demonstration of, two associative learning paradigms: visual associative learning and spatial learning. Both have been developed on the restrained cockroach so that later these methods can be employed in conjunction with electrophysiology. By projecting their antennae intermittently towards a position of potential food sources, cockroaches sample salient information. Here, this antennal behavior, called an "antennal projection response (APR)," is used to demonstrate long-term memory where an APR is elicited by a conditioning stimulus (CS: green light) paired with a spatially coincident odor (unconditioned stimulus: US). The acquired APR to the green light cue persists for up to 72 hours. Spatial learning is also a vitally important behavior in most animals that must remember locations of food and landmarks and that must navigate. Spatial learning abilities were here tested by observing APRs towards a cue, where the cockroach learns the position of a visual cue (CS) associated with a food odor (US), relative to the position of another visual stimulus in the contralateral visual field (the contralateral visual reference stimulus: ConRS). Memory of positional information, tested by altering the relative positions of the CS and ConRS, was investigated. Cockroaches showed significant APRs to visual cues not only when a position of the visual cue and spatial reference cue were exactly matched during training trials, but also during tests when the relative angles between the visual cue and spatial reference cue were matched but rotated around the head's vertical axis. When these angles were not the same as the angle used for training, the CS was not recognized. These results suggest that cockroaches employ two different mechanisms to find a food source: retinotopic matching and recognition of angular relationships between a source and landmark. The application of these paradigms to studies that could investigate possible neural mechanisms of these behaviors is discussed.