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Michaels, Simone ColetteDevelopment and Assessment of Artificial Manduca sexta Forewings: How Wing Structure Affects Performance
Master of Sciences (Engineering), Case Western Reserve University, 2016, EMC - Aerospace Engineering
This research presents novel fabrication and testing techniques for artificial insect wings. A series of static and dynamic assessments are designed which allow consistent comparison of small, flexible wings in terms of structure and performance. Locally harvested hawk moths are tested and compared to engineered wings. Data from these experiments shows that the implemented replication method results in artificial wings with comparable properties to that of M. sexta. Flexural stiffness (EI) data shows a considerable difference between the left and right M. sexta wings. Furthermore, EI values on the ventral wing side are found to be consistently higher than the dorsal side. Based on dynamic results, variations in venation structure have the largest impact on lift generation. Lift tests on individual wings and wing sets indicate detrimental effects as a result of wing-wake interaction.

Committee:

Roger Quinn (Advisor); Mark Willis (Committee Member); Richard Bachmann (Committee Member)

Subjects:

Aerospace Engineering; Aerospace Materials; Biology; Engineering; Entomology; Mechanical Engineering

Keywords:

Manduca sexta; artificial wings; wing fabrication; biomimicry

Talley, Jennifer LindyMales Chasing Females: A Comparison of Flying Manduca sexta and Walking Periplaneta americana Male Tracking Behavior to Female Sex Pheromones in Different Flow Environments
Doctor of Philosophy, Case Western Reserve University, 2010, Biology
Molecules evaporating from objects are carried by air creating a plume of odor that many animals use to find ecologically important resources. Odor plumes are dominated by turbulence (fluctuations in air velocity) when carried long distances, which results in a patchily distributed odor with high and low concentration areas surrounded by clean air. The consequence of this patchy distribution is that concentration itself is not a reliable directional signal for navigation towards a source. Therefore, many insects orient to the direction of air flow to aim themselves toward a source. When tracking species-specific sex pheromone within an experimental wind tunnel, the males of the Tobacco Hornworm Moth (Manduca sexta) fly and the American Cockroach (Periplaneta americana) walk, orienting themselves upwind. These males alter their tracking behavior in response to changing flow and odor signals caused by structures designed to mimic natural turbulence. Flow and odor signal characterizations with hot wire anemometry and electroantennograms explain those differences in the behavior of walking and flying trackers; walking cockroaches appear to respond better to spatial flow information and distinct odor/clean-air boundaries while flying moths appear to respond better to temporal flow information and odor plumes with larger cross sections. However, my results also show that cockroaches may be capable of a more complex odor tracking strategy than a purely spatial comparison between their two antennae because unilaterally antennectomized cockroaches can track a plume and find an attractive odor source. Computer simulations show how purely spatial or temporal control algorithms perform in different turbulent odor distributions, and are then used to test hypotheses about how flying and walking trackers utilize flow and odor signal information differently to find a source. The changes in behavior of insects tracking odor using different modes of locomotion in different environments are understood through measurements of the change in flow and odor information in those environments. Hypotheses developed from these studies are then tested in computer simulated environments with simulated sensors that match the odor and flow information in the experimental wind tunnel to illustrate how well those hypotheses explain the observed behavior.

Committee:

Mark A. Willis, PhD (Advisor); Christopher A. Cullis, PhD (Committee Chair); Hillel J. Chiel, PhD (Committee Member); Debra Wood, PhD (Committee Member); Roy E. Ritzmann, PhD (Committee Member); Edward B. White, PhD (Committee Member)

Subjects:

Behaviorial Sciences; Biology

Keywords:

chemo-orientation; pheromone; tracking behavior; electroantennogram; antennectomy; simulation; odor plumes; anemotaxis; spatial; temporal; periplaneta americana; manduca sexta; insect; flight; walking;

Rutkowski, Adam JA BIOLOGICALLY-INSPIRED SENSOR FUSION APPROACH TO TRACKING A WIND-BORNE ODOR IN THREE DIMENSIONS
Doctor of Philosophy, Case Western Reserve University, 2008, Mechanical Engineering
An autonomous vehicle that can track a wind-borne odor plume to its source could locate lost pets and people, pipeline breaks, illegal drug labs, or improvised explosive devices (IEDs). This work explores moth-inspired strategies for tracking a wind-borne odor plume with an aerial vehicle. When tracking an odor, moths counter-turn horizontally back and forth across the wind while generally progressing upwind. Previous studies suggest that moths maintain their altitude at the mean altitude of the odor plume and that the timing of their turns is controlled by an internal mechanism. The ability of moths to stabilize their altitude while tracking an odor plume was examined in a laboratory wind tunnel. It was hypothesized that an enriched visual environment in the lateral visual field would allow moths to stabilize their altitude. The moths did not maintain their altitude fixed at the mean altitude of the odor plume. Instead, they used a combination of horizontal and vertical undulations to search for odor in a plane normal to the wind direction while making upwind progress. The three dimensional observations of moth odor tracking inspired the design of strategies that direct an agent to control its turn rate in the wind-normal plane, and upwind speed, as independent functions of the measured odor concentration. The aerial agent estimates its egomotion, altitude, the wind velocity, and the ground structure using a new technique that fuses visual and mechanosensory input. Two odor tracking strategies – Spiraling and Spiraling5 - were developed and tested in simulation on an odor tracking software platform called OdorTracker. The behavior of the Spiraling strategy was dependent on the odor concentration while the Spiraling5 strategy was dependent on the time derivative of odor concentration. Using either strategy, the simulated agent approached the odor source with moth-like undulations in the vertical and horizontal directions without internal counter-turn timers; however, the Spirarling5 algorithm sometimes became unstable. Not only did the odor tracking strategies allow the tracking agent to reach the odor source, they also allowed the tracking agent to remain in the vicinity of the odor source for several seconds, which also agrees with moth behavior.

Committee:

Roger Quinn (Advisor)

Keywords:

odor tracking; odor tracing; guidance; vision; moth; Manduca sexta; olfaction; unmanned aerial vehicle; optic flow; robot

Drummond, Christopher AnsonRegulation of Ecdysone 20-Monooxygenase Activity in the Tobacco Hornworm, Manduca sexta and the Apparent Occurrence of this Activity in Ascaris suum (Nematoda)
Doctor of Philosophy (Ph.D.), Bowling Green State University, 2011, Biological Sciences
At specific intervals, increased concentrations of two steroid hormones, i.e., ecdysone (E) and 20-hydroxyecdysone (20E), elicit developmental changes in arthropods. Conversion of E to the active molting hormone, 20E, in the tobacco hornworm Manduca sexta is catalyzed by the cytochrome P450-containing ecdysone 20-monooxygenase system (E20M). During embryogenesis, M. sexta E20M activity increased for the first 72 hours at which time it peaked and subsequently significantly declined. The increased activity coincided with the increase of free ecdysteroids and the progression of two embryonic molts. In midgut tissue of fifth instar M. sexta, decreases in second messenger 3’,5’cyclic guanosine monophosphate (cGMP) concentration inhibited day five E20M activity, but increases in cGMP concentration restored E20M activity. Midgut cGMP content peaked on day five of the instar in concert with the highest level of E20M activity observed. Molecular studies with midgut tissue demonstrated that the E agonist RH-5849 elicited increases in E20M (the shade gene) expression. In the presence of two guanylate cyclase inhibitors, E20M expression significantly increased. Inhibition remediation by pharmacological means resulted in significantly decreased shade expression. While it is unclear as to where cGMP exerts its effects on E20M activity, the data indicated that the second messenger affected the level of transcription, translation, or enzyme activity either individually or in some combination. Interestingly, E20M activity also was found to be affected by six synthesized anthraquinones suggesting that these compounds can serve to disrupt M. sexta development. Lastly, E20M-like activity was observed in female Ascaris suum (Nematoda) both in muscle and reproductive tissue. Although E20M localization in muscle was unclear, in reproductive tissue E20M activity resided mainly with microsomes. This work provides a number of important insights into the regulation of M. sexta E20M during development, a role of cGMP in these events, and the possible occurrence of E20M in the parasitic nematode Ascaris suum.

Committee:

Carmen Fioravanti, Ph.D. (Committee Chair); Daniel Pavuk, Ph.D. (Committee Member); Lee Meserve, Ph.D. (Committee Member); Scott Rogers, Ph.D. (Committee Member); Hangfeng Chen, Ph.D. (Committee Member)

Subjects:

Agriculture; Animal Sciences; Animals; Biochemistry; Biology; Cellular Biology; Developmental Biology; Endocrinology; Entomology; Organismal Biology; Parasitology; Physiology

Keywords:

Ecdysone 20-monooxygenase; Manduca sexta; second messengers; cyclic guanosine monophosphate; ecdysteroidogenesis; steroids; ecdysone; 20-hydroxyecdysone; endocrinology

Vandock, Kurt P.Mitochondrial Transhydrogenations in Manduca sexta: Relationship between Reversible NADPH → NAD+ Transhydrogenase and Ecdysone 20-Monooxygenase in Fifth Instar Larvae
Doctor of Philosophy (Ph.D.), Bowling Green State University, 2010, Biological Sciences
Midgut mitochondria from fifth larval instar Manduca sexta exhibited a transhydrogenase that catalyzes the following reversible reaction: NADPH + NAD+ ↔ NADP+ + NADH. The NADPH-forming transhydrogenation occurred as a non energy- and energy-linked activity. Biochemical characterization for reversibility, energy-linkages, pH optima, stability to dialysis/heat denaturation, transmembrane proton translocation and localization were accomplished. During the ten day developmental period preceding the larval-pupal molt (fifth larval instar), significant peaks in the mitochondrial transhydrogenase activities of midgut and fatbody tissues were noted and these peaks were coincident with the onset of wandering behavior and with the 50-fold increase in ecdysone 20-monooxygenase (E20-M) activity previously reported for M. sexta midgut. Since E20-M preferentially uses NADPH in catalyzing ecdysone conversion to the physiologically active molting hormone, 20-hydroxyecdysone, the physiological and developmental significance of the mitochondrial, NADPH-forming energy-linked transhydrogenations are apparent. Using isolated mitochondrial membranes, the M. sexta transhydrogenase was subjected to kinetic analysis pertaining to the NADPH → NAD+ as well as non energy-linked and the ATP-dependent, energy linked NADH → NADP+ reactions. Kinetic analysis demonstrated that the reversible insect transhydrogenase is subject to site-specific inhibition, contains two substrate binding sites (viz., NADP(H) and NAD(H)), and is susceptible to end-product inhibition. The effect of various allelochemicals on the M. sexta transhydrogenations was also evaluated. Taken together, the findings of this dissertation support a distinct physiological role of mitochondrial transhydrogenase in M. sexta post-embryonic development.

Committee:

Carmen Fioravanti, PhD (Advisor); Raymond Larsen, PhD (Committee Member); Martin Mitchell, PhD (Committee Member); Mark Munson, PhD (Committee Member); Jill Zeilstra-Ryalls, PhD (Committee Chair)

Subjects:

Biochemistry; Biology; Cellular Biology; Entomology

Keywords:

Transhydrogenase; Manduca sexta; Mitochondria; NADPH; NADH; NAD; NADP; ATPase; Electron Transport; Kinetics; Allelochemicals; Flavonoids; Insect; Ecdysone 20-monooxygenase; 20-hydroxyecdysone; insect development.