Experiment s were conducted to see if Erwinia amylovora (Burrill) Winslow et al. overwinters inside living host tissue in Utah. Bacteria, collected from apple, pear, mountain ash, chokecherry and Pyracantha, were used in the experiment. Isolates taken from buds and inner bark plated on nutrient yeast dextrose agar, we re tested by serological and bacteriophage techniques. Those showing positive tests were then inoculated into Bartlett pear seedlings to test virulence. Both virulent and avirulent isolates were isolated from each species of plant in the experiment. Pathogenic bacteria were isolated from diseased tissue near cankers, as well as from apparently healthy inner bark as far as six inches below the cankers. Pathogenic bacteria were also isolated from healthy appearing buds in the vicinity of cankers. Nearly 15 percent of isolates from hosts other than apple and pear were pathogenic to Bartlett pear seedlings. A good deal of variation existed among the bacterial isolates. Antisera developed from four isolates of Erwinia amylovora proved to be a good means of identification for the pathogen.

No description available.

Mule deer are an important rangeland grazer, large prey species, and game animal for the state of Utah, so herd size is monitored and managed actively. A significant cause of population decline is poor overwintering survival, including from the lack of available forage during winter months. Mule deer energy storage is correlated with greater overwintering success, so physical estimates of energy storage including body condition score (BCS), rump fat (RF), and loin thickness (LT), can be used to track and predict a herd's health. Current methods of collecting deer information are costly, time consuming, and cause physical stress to deer, so here we sought to test if a microbiome analysis could be used to predict deer overwintering success. We analyzed nearly 1000 fecal samples collected from deer in Utah over a five-year period. We found that the microbiome composition of these samples shared characteristics with published reports of other reported ruminant species. Also, the location and time when the samples were collected significantly influenced mule deer microbiota composition and abundance. We found that there is a relationship between microbes and health measures (BCS, RF, LT), including some microbial abundances that could predict the health measures of mule deer several months ahead of time. There were also microbial groups whose abundances were significantly correlated with the latitude and elevation of the deer. Finally, a longitudinal analysis on a subset of sampled deer produced slightly different results than the broad analysis of all samples, including suggesting that some of the differences in microbiota composition with time may have been related more to sampling distinct deer at different time points, rather than that the deer microbiota composition changed with time. . These results suggest possible candidate microbial taxa for use in developing assays to replace current methods of measuring and tracking deer health.

No description available.

No description available.

Lopholeucaspis japonica (Cockerell) (Hemiptera: Diaspididae), commonly known as Japanese maple scale (JMS), is an invasive pest established in the United States in 1914. Over the past decade, JMS infestations have escalated, posing a significant threat to the nursery industry, and resulting in economic losses from unsellable infested plants. The limited understanding of JMS hampers the development of effective management strategies, intensifying the financial impact of this destructive pest. To contribute to the development of a sustainable pest management program, it is crucial to acquire knowledge of JMS's natural history, biology, and dispersal capabilities. Management costs can be reduced by determining the optimal timing for scouting and spraying through peak crawler emergence and the identification of overwintering life stages. Understanding JMS dispersal patterns within tree canopies can lead to the refinement of scouting methods, such as strategically placing the tape method (for monitoring crawlers). A two-year study took place at two separate locations and on boxwoods (2022-2023) and red maples (2023). Our phenology findings indicated that there were two generations and prolonged crawler presence which can extend over a period of 34 weeks (March-October) during the growing season. The first generation of crawler emergence on boxwoods started as early as the second week of March [110-114 Growing Degree Days in base 50°F (GDD50)], with the first peak occurring in mid-June [1179-1514 GDD50]. The second generation depending on the year began in July and peaked between early September and mid-August due to overlapping from prolonged presence of crawlers. Crawler emergence on maples indicated the first peak during the second week of July, followed by the second peak during the third week of August. Management practices, including monitoring and chemical control and based on phenology data, could be suggested to begin early March and continue throughout the season putting high pressure on crawlers during the peaks of activity. Overwintering studies from this project suggested JMS could be developing throughout winter with immatures found in January and February while in March the highest population was adults. Using horticultural oil during the winter months may help with JMS infestations. To investigate dispersal patterns, the canopy of experimental plants of maples and boxwoods were divided into top, middle, and bottom sections based on plant height. Comparative analysis of JMS crawler densities within the canopies of maples indicated that the middle canopy sections exhibited higher crawler densities compared to the top sections. However, when evaluating all three sections (top, middle, and bottom), the bottom sections displayed the highest crawler densities. Examination of cardinal points within the top and middle canopies of maples revealed a widespread distribution pattern. In contrast, no significant differences in crawler densities were observed between the various canopy sections of boxwoods, indicating a uniform distribution across the plant. / Master of Science in Life Sciences / Japanese maple scale (JMS), scientifically known as Lopholeucaspis japonica, is an invasive pest damaging ornamental plants in the United States since 1914, particularly affecting the nursery industry in the Southeast, including Virginia. This study aimed to enhance the understanding of JMS phenology, overwintering biology, and dispersal patterns. A two-year study took place at two separate locations and on boxwoods (2022-2023) and maples (2023). Phenology and dispersal patterns were monitored using the tape method to count crawlers per cm². Over two years, 100 JMS specimens were inspected monthly for three consecutive winter months to record overwintering life stages. Across both years and crops there were two peaks of activity with the first peak being between June and July and the second falling in between August and September. For overwintering, higher numbers of JMS immatures were found in January and February, and adults in March. To investigate dispersal patterns, the canopy of experimental plants of maples and boxwoods were divided into top, middle, and bottom sections based on plant height. Comparing JMS crawler densities in maples between the top and middle canopy sections revealed higher densities in the middle. However, when all three sections in maples were compared, the bottom had the highest density of crawlers. Cardinal points within the top and middle canopies were investigated for maples only and showed a widespread distribution when examining those points. For boxwoods, no significant difference was found in crawler densities between plant sections. This knowledge will empower nursery growers to make informed decisions, optimize their efforts in monitoring and control, and minimize the economic impact caused by JMS infestations.

The brown marmorated stink bug (Halyomorpha halys) (Stål) is known for overwintering in human homes. Studies were conducted to understand the behavior of adult bugs in response to characteristics of potential overwintering structures including gap sizes, light, and presence of dead conspecifics. In a test where bugs were placed in increasingly tight boxes, most bugs settled in gaps 4.5 - 5.5 mm high. None settled in a space less than 3.5 mm high. In boxes with constant tightness, bugs tended to move to the back, and primarily settled along walls and in corners. In both box types, bugs tended to turn and face the cavity entrance during settling. In tests of responses of disturbed overwintering bugs to common household light bulbs over the course of a year, bugs were taken from shelters and exposed to lit bulbs. Bug responses were seasonal, with attraction to light bulbs in spring and summer, but little or no consistent response in fall or winter. The lack of response occurred more often at night than in afternoons. Because not all bugs survive the winter, corpses can accumulate. Single shelter-seeking H. halys were found not to respond to the presence of dead aggregations from the previous years unless touch was possible, in which case aggregations were joined. Dead aggregations from the same year had a repellent effect. Presence of a single dead bug from the same year did not provide any survivorship advantage to overwintering bugs. Results suggest possible improvements to trap shelters. / Master of Science in Life Sciences / The brown marmorated stink bug (Halyomorpha halys) is known for overwintering in human homes. This research investigated the responses of these bugs to some characteristics of overwintering structures, including crevice tightness preference, light sources, and dead bugs leftover from previous years. Tightness experiments indicated that bugs in crevices with hard walls prefer to settle in spaces between 4.5 and 5.5 mm high. Bugs also tended to stay on the floor, go back as far as they could, and face the entrance of the crevice. These findings will help improve overwintering box designs for collection and research, and will help pest control professionals focus their efforts. When bugs were disturbed and exposed to common household light bulbs, they tended to move toward the bulbs in late summer and in spring, but responded less in fall and winter, and responded more often in the afternoon than at night. Bugs were also exposed to other dead bugs in several ways. When lone bugs were exposed to groups of dead bugs from previous years, they went to them only if they could touch them. Single dead bugs had less of an impact. Exposure to groups of dead bugs from the same year drove live bugs away. Overwintering brown marmorated stink bugs do not appear to eat other bugs that have recently died. These results suggest several possible improvements to the designs of trap shelters used for research and control.

The redbanded stink bug, Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae), is a non-native pest of soybeans in the Americas outside of the Carribean. Mortality of overwintering adults due to cold exposure has been implicated as a major driver of interannual fluctuations in the occurrence of P. guildinii in the southeastern United States, but formal investigations of drivers, including factors other than cold temperatures, are rare. We conducted overwintering assays with field-collected P. guildinii to quantify survival and coupled historical occurrence with climatic data to develop a species distribution model. We found that leaf litter provides substantial insulation from lethal temperatures and thus increases the potential for overwintering survival of P. guildinii. Our species distribution model indicates that the northern extent of the insect’s range is limited by winter temperatures, but that can potentially expand the range hundreds of kilometers in a growing season.

Little is known about the tick populations found within the central Appalachian/southwestern region of Virginia. The main focus of this research was to better assess local tick communities in the central Appalachian-Southwestern region of Virginia, which was addressed by determining species diversity, habitat associations, seasonal phenology, pathogen prevalence, and ecological factors that influences tick presence and abundance. A field study was conducted from June 2019 - November 2020 across 8 counties and 3 habitat types. Forested habitats exhibited greater tick species diversity than pasture and urban habitats. Each tick species was observed to be associated with particular habitats. The presence of B. burgdorferi sensu stricto (causative agent of Lyme disease), the human variant of A. phagocytophilum (causative agent of human granulocytic anaplasmosis), and Powassan virus (the causative agent of Powassan encephalitis) were detected in collected field specimens, suggesting a significant threat to public health. The detection of Powassan virus RNA in local Ixodes scapularis ticks is the first evidence of this viral pathogen within the region. The overwintering abilities of ticks, whose populations are expanding or becoming more invasive, including Haemaphysalis longicornis, Amblyomma americanum, and Amblyomma maculatum, were examined through a combination of laboratory and field experiments. Amblyomma americanum and H. longicornis nymphal ticks had a lower supercooling temperature than adult ticks, suggesting their potential to overwinter better; A. maculatum nymphs had similar average supercooling temperatures as the other two species at nymphal stage. Via a field experiment, A. americanum, H. longicornis, and A. maculatum were subjected to natural elements of a Virginian winter in a two-factor design investigating elevation and potential insulation coverage. Elevation and insulation coverage were found to have no significant impact on the overwintering survival of H. longicornis and A. americanum. However, the life-stage of the tick was determined to be a significant factor that dictated the survival of ticks of these species. Overwintering survival of Amblyomma maculatum nymphs was influenced by insulation (proxied by leaf litter); which may be attributed to this tick's preference of drier climate. Low overwintering survival suggests that a tick may not be able to establish a permanent population within the area. / Master of Science in Life Sciences / Ticks can transmit many pathogens, bacteria or viruses that cause disease, to both humans and animals. Diseases associated with ticks can include Lyme disease, Human Anaplasmosis, Ehrlichiosis, Rocky Mountain spotted fever, as well as viral illnesses. The pathogens that cause these diseases are vectored by specific tick species. Currently, there are no published reports of tick species present within the central Appalachian/southwestern region of Virginia. A study to determine local tick populations presence and the factors influencing their maintenance in the environment was conducted. Additionally, field collected specimens were screened to assess pathogen prevalence within the region. I confirm the presence of Borrelia burgdorferi sensu stricto (causative agent for Lyme disease), Anaplasma phagocytophilum (causative agent for Human Granulocytic Anaplasmosis), and Powassan virus within Ixodes scapularis, commonly referred to as black-legged ticks. Habitat (forest, urban, pasture) was a significant influencing factor on the presence of I. scapularis, Amblyomma americanum, and Haemaphysalis longicornis (e.g., the latter species was predominantly found in pasture habitats). Secondly, I investigated how well three sympatric tick species would overwinter within the region. Survival of a tick is heavily dependent upon their ability to withstand desiccation, obtain a blood meal from a host, mate, and reproduce. Certain ticks may be limited to certain regions based on elevation, temperature, and relative humidity. I investigated the influence of elevation and insulation coverage (presence of leaves vs. no leaves) on A. americanum (Lone star tick), H. longicornis (Asian longhorned tick), and A. maculatum (Gulf Coast tick). Elevation and insulation coverage had no significant impact on the overwintering survival of the Lone star and Asian longhorned ticks. Tick survival was mainly dictated by what life-stage they were in; Lone star ticks survived better as adult than at other life stages. Asian longhorned ticks survived better as nymphs than larva and adults. Insulation coverage influenced the overwintering survival of the Gulf Coast tick. These ticks survived better with no leaves, which may be associated with their preference of drier climates.

In Ontario, the common snapping turtle, Chelydra serpentina, is listed as Special Concern and is at risk of decline. These long-lived organisms are particularly susceptible to anthropogenic threats owing to delayed sexual maturity, low recruitment and reliance on low adult mortality. Threats facing this species include road mortality and habitat loss and/or destruction. These threats are anecdotally evident within Cootes Paradise Marsh, a highly urbanized river-mouth coastal marsh located in a heavily urbanized region at the western end of Lake Ontario. Straddling Dundas and Hamilton, the wetland is bisected by Cootes Drive, a four-lane highway (maximum speed 80 km/h) that has resulted in fatal collisions with wildlife. We re-analyzed data from previous capture-mark-recapture studies and determined that the snapping turtle population has declined by almost 90% from 1985 to 2002. Using road mortality survey data collected by citizen science group Dundas Turtle Watch, we determined that some of this decline can be attributed to road mortality. Through radio tracking, we also found that the population remains at risk to road mortalities because their home ranges overlap surrounding roads. Besides the direct negative effect of mortality, roads impart broader and additional unintended consequences by hindering turtles’ access to critical nesting and overwintering habitat. We acquired digital orthophotos to assess changes in availability of nesting habitat, which is crucial for recruitment and population maintenance. Potential nesting habitat decreased by almost 50% between 1934 and 2010. Through nest surveys conducted in 2017, we determined that there is currently disproportionate use of artificial gravel mounds for nesting. For overwintering purposes, snapping turtles appear to be using a wide range of habitat types within the upland terrestrial matrix of the wetland ecosystem. We also confirmed that sites used for overwintering did not cool below inhibiting temperatures between early December and end of March. This study illustrates the toll that road mortality can have on urbanized herpetofauna populations and highlights the importance of ensuring that recovery plans focus on restoring both the quantity and quality of nesting and overwintering habitats. / Thesis / Master of Science (MSc) / Common snapping turtles (Chelydra serpentina) exhibit “slow” life history traits which make them particularly vulnerable to human activities, such as urbanization. In this thesis, I used demographic and road mortality information to provide evidence that the population of snapping turtles living in the degraded Cootes Paradise Marsh ecosystem has substantially declined over the past three decades. I also assessed current availability of nesting and overwintering habitat that are both essential for maintaining a viable population of snapping turtles. My results highlight the devastating effects road mortality can impart on long-lived freshwater reptiles, and cautions against further modification or destruction of their critical habitat.