No description available.

Call number: LD2668 .T4 1979 G34 / Master of Science

No description available.

No description available.

Community structure in backswimmers (Hemiptera: Notonectide), was investigated via extensive sampling throughout southern Arizona, USA, and Sonora, Mexico, from 1980 through 1985. Co-occurrence and relative abundance data were collected in more than 65 ponds, and in 177 rock basin pools (tinajas) in 21 canyons in the Southwest. Eleven species were collected in Arizona and Sonora, and were divided into two groups, species found in ponds and species found in tinajas. Only two species occurred significantly in both habitats. Tinaja species are largely Southwst endemics, and pond species are widespread or tropical in distribution. Data from artificial habitats suggest that the tinaja species use relatively high topographic relief, and pond species use relatively large surface area as cues to find their respective habitats. Two body size patterns are consistent with a competition explanation of local community structure. The body sizes of co-occurring species are relatively evenly distributed among species occurring in pond and tinaja habitats, and species of similar body size tend not to co-occur (body size ratio <1.3). For example, Notonecta kirbyi and N. lobata only co-occur in tinajas at intermediate elevations; lobata is absent at high elevations and kirbyi is absent at lower elevations. N. indica occurs in ponds at lower elevations and N. unifasciata occurs at higher elevations. Buenoa hungerfordi and B. arizonis both occur in tinajas, but not at the same time of year. Predation was shown experimentally not to be important in producing the body size pattern. Notonecta spp. preyed heavily on the smaller of two Buenoa species presented, an effect that would act to reduce the community-wide body size ratio. Because notonectid communities have larger body size ratios than expected by chance, predation would seem not to be involved in producing this pattern. However, predation does appear to reinforce microhabitat partitioning between the two genera in that Buenoa occupy deeper portions of the water column in the presence of Notonecta than in their absence. This further displaces coexisting individuals of the two genera in space, and reduces overlap in foraging for aquatic insect prey and promotes coexistence.

A thesis submitted in fulflment of the requirements for the degree of Doctor of Philosophy in the School of Computer Science and Applied Mathematics. November 2015 / The understanding of uid ow at microscale geometrics is an increasingly important eld in applied science and mechanics, especially in bioinspiration and biomimetics. These elds seek to imitate processes and systems in biology to design improved e cient engineering devices. In this thesis, inspired by the e ciency of the insect tracheal system in transporting respiratory gases at microscale, mathematical models that both mimic and explain the gas exchange process are developed. Models for the simultaneous movement of respiratory gases across the insect spiracle, gas transfer from one respiratory chamber to the next, end di usion and tissue absorption at the tracheole tips, and tracheal uid transport are presented. Expressions for tracheal partial pressures of the respiratory gases, rate of change of gas concentrations, rate of tracheal volume change, spiracle behaviour on net gas ow, cellular respiration and tissue absorption, and global gas movement within the insect are presented as well. Two versions of bioinspired pumping mechanism that is neither peristaltic nor belongs to impedance mismatch class of pumping mechanism are then presented. A paradigm for se- lectively pumping and controlling gases at the microscale in a complex network of channels is presented. The study is inspired by the internal ow distributions of respiratory gases produced by rhythmic wall contractions in dung beetle tracheal networks. These networks have been shown to e ciently manage uid ow compared to current produced micro uidic devices. The insect-like pumping models presented are expected to function e ciently in the microscale ow regime in a simple or complex network of channels. Results show the ability to induce a unidi- rectional net ow by using an inelastic channel with at least two moving contractions. These results might help in explaining some of the physiological systems in insects and may help in fabricating novel e cient micro uidic devices. In this study, both theoretical and the Di erential Transform Method are used to solve the exible trachea with gas exchange problem as well as the 2D viscous ow transport with or without prescribed moving wall contractions problem. Both Lubrication theory and quasi- steady approximations at low Reynolds number are used in the derivation of theoretical analysis. ii Moreover, an analytical investigation into the compressible gas ow with slight rarefactions through the insect trachea and tracheoles is undertaken, and a complete set of asymptotic analytical solutions is presented. Then, estimation of the Reynolds and Mach numbers at the channel terminal ends where the tracheoles directly deliver the respiratory gases to the cells is obtained by comparing the magnitude of the di erent forces in the compressible gas ow. The 2D Navier-Stokes equations with a slip boundary condition are used to investigate the compressibility and rare ed e ects in the respiratory channels.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Naturalists, state administrators and farmers in France and its colonies developed a myriad set of techniques over the course of the long eighteenth century to manage the circulation of useful and harmful insects. The development of normative protocols for classifying, depicting and observing insects provided a set of common tools and techniques for identifying and tracking useful and harmful insects across great distances. Administrative techniques for containing the movement of harmful insects such as quarantine, grain processing and fumigation developed at the intersection of science and statecraft, through the collaborative efforts of diplomats, state administrators, naturalists and chemical practitioners. The introduction of insectivorous animals into French colonies besieged by harmful insects was envisioned as strategy for restoring providential balance within environments suffering from human-induced disequilibria. Naturalists, administrators, and agricultural improvers also collaborated in projects to maximize the production of useful substances secreted by insects, namely silk, dyes and medicines. A study of these scientific and administrative techniques will shed light on how scientists, administrators and lay practitioners in the French Enlightenment came to assess and manage the risks and opportunities afforded by the related processes of commercial and ecological globalization.

Abstract not available

Aggregation and species association of 9 species of phytophagous and predaceous mites were studied for 6 yr in an orchard with 100, 2 m tall 'Red Delicious' apple trees. To quantify aggregation, a method was developed that is powerful, and easily interpreted. It relates the proportion of habitat occupied to mean density of the organism, and allows discrimination of aggregation differences between data sets. We found that plant feeders were more aggregated than predators, and active life stages were less aggregated than eggs. Specifically, webspinning spider mites (Tetranychus urticae + Eotetranychus sp.) were the most aggregated. Panonychus ulmi was less aggregated than the webspinning mites, and Bryobia rubrioculus was the least aggregated of the spider mites. Zetzellia mali, the slowest moving predator, had the greatest aggregation of all the predators. The rapid moving phytoseiids were the least aggregated of all the mite species studied, with the specialist predator Metaseiulus occidentalis having the greatest aggregation, the generalist predator Typhlodromus pyri having medium aggregation, and the fast moving Amblyseius andersoni having the least aggregation. Predator-predator, predator-prey, and prey-prey associations were measured using Yule's V association index. Predator-predator associations were the strongest and most consistent, showing a consistent seasonal pattern of neutral-negativeneutral association. Negative associations of T. pyri with other predators were the strongest, which is consistent with evidence that this mite can detect other predators. Predator-prey seasonal associations were weak and mixed, and interactions between prey species were generally weakly positive, probably because of similar habitat preferences. Predaceous mites were generally more aggregated when competing with other predators, possibly allowing the coexistence of 3 predators simultaneously for 6 years via mechanisms proposed by the "aggregation theory of coexistence". G. occidentalis showed the greatest change of aggregation when other predators were present, Z. mali and T. pyri also showed significant changes in aggregation when they were with other predators, but A. andersoni (the largest, fastest predator in our study) showed no changes in aggregation. T. pyri's aggregation increased the most when in the presence of Z. mali, perhaps because of egg predation by the stigmaeid, or because T. pyri could detect the other predator. / Graduation date: 1999