Life Sciences Commons^™

Browntail Moth (Euproctis Chrysorrhoea) Integrated Pest Management Program: Evaluation Of Monitoring Traps And Biopesticides, Sadia Crosby

Electronic Theses and Dissertations

Browntail Moth (BTM; Euproctis chrysorrhoea) is a non-native species currently outbreaking in Maine. BTM are polyphagous folivores and feed on a variety of woody plant species, including many economically and ecologically important ornamental and forest trees such as oaks and apples. Human health is also a concern as BTM larvae produce urticating hairs that can cause severe dermatitis in people. New monitoring and management programs are urgently needed, with the current population densities reaching a 100-year high.

The Maine Forest Service monitors BTM populations by visually assessing winter nest densities and defoliation patterns, both time and labor intensive. This …

A Social And Ecological Approach To Mosquito Species Distribution Across Land Use In Bangor, Maine, Megan L. Schierer

Electronic Theses and Dissertations

Mosquitoes are ubiquitous pests and infectious disease vectors. However, not all mosquito species bite humans, or are competent pathogen vectors between bloodmeal hosts. Along with climatic variables like temperature and rainfall, mosquito species distribution is determined by aquatic habitat availability for juvenile mosquito development, and terrestrial habitat and host availability for adult mosquitoes. There is variation in the preferred aquatic habitat for gravid female oviposition and subsequent larval development. Some mosquito species’ oviposition and development are associated with ephemeral water sources (e.g., floodplains), others prefer more permanent water sources (e.g., bogs or vernal pools). Other mosquitoes have evolved to occupy …

Biophysical Interactions And Social Perceptions Of Ixodes Scapularis (Acari: Ixodidae) Exposure Risk Due To Climate Change, Brittany Schappach

Electronic Theses and Dissertations

Increased temperature variances are being recorded in Maine due to climate change, contributing to increased densities of blacklegged ticks (Ixodes scapularis) and concomitant increase in reported cases of tickborne diseases across the state. Understanding the interactions between mean temperature and temperature variance in relation to overwinter tick survival is crucial in understanding the tick’s geographical expansion limits to create better prediction models for their expansion. The goals of this study were to determine the interacting microclimate effects of winter temperature variance and mean temperatures on tick mortality, which month nymphal blacklegged ticks experience highest mortality, and assess the connection between …

Effects Of A Novel Dsrna-Based Insecticide On The Colorado Potato Beetle, Samuel J. Pallis

Electronic Theses and Dissertations

The Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) is one of the most destructive pests of the cultivated potato, Solanum tuberosum. Colorado potato beetles have been devastating potato crops for the past 150 years and have expanded their range during that time, becoming a globally distributed agricultural pest. Potato beetles are well-suited to agricultural environments and have evolved some degree of resistance to virtually all chemical insecticides. As such, the development of novel control methods to both control potato beetle populations and manage the evolution of insecticide resistance are in constant demand

The knockdown of gene functioning through ribonucleic acid …

Adaptation Strategies For Wild Blueberry Growers In A Changing Climate: Mulching Effects On Crop Productivity And Fertility Effects On Blueberry Gall Midge, Rebecca Gumbrewicz

Electronic Theses and Dissertations

Wild blueberry (Vaccinium angustifolium Aiton.) cropping systems are considered resilient to environmental changes due to ecological and genetic diversity within each field. However, wild blueberries can be sensitive to weather fluctuations that cause extreme temperature or moisture regimes. Climate change in Maine is represented by increasing rates of warming temperatures, more intense precipitation events, and more frequent atmospheric “blocking” patterns. Warming temperatures result in the northward expansion of pest ranges and altered growing seasons. More extreme rainfall events lead to damaged plantings and soil erosion. Atmospheric blocking leads to an increased likelihood of heat waves and drought. Two experiments were …

The Relative Abundance And Diversity Of Parasitoids Of The Browntail Moth (Euproctis Chrysorrhoea L.) And Factors That Influence Their Population Dynamics, Karla S. Boyd

Electronic Theses and Dissertations

The browntail moth (Euproctis chrysorrhea) is an invasive forest pest that has been present in the Northeast since it was first introduced from Europe in 1897. Originally, its range expanded very rapidly until it reached its peak invasion of 150,000 km², which included most of New England and parts of Southern Canada and Long Island, NY, in 1915. After this point, its range collapsed until only relic populations remained on islands in the Casco Bay Region of Maine and outer Cape Cod in Massachusetts. In 2016, a large population outbreak occurred that expanded its range into …

The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga

Electronic Theses and Dissertations

Dickeya dianthicola (Samson) causing blackleg and soft rot was first detected in potatoes grown in Maine in 2014. Previous work has suggested that insects, particularly aphids, may be able to vector bacteria in this genus between plants, but no conclusive work has been done to confirm this theory. In order to determine whether insect-mediated transmission is likely to occur in potato fields, two model potato pests common in Maine were used: the Colorado potato beetle (Leptinotarsa decimlineata Say) and the green peach aphids (Myzus persicae Sulzer). Olfactometry and recruitment experiments evaluated if either insect discriminates between infected and …

Spatial And Temporal Variation In The Aquatic Invertebrate Community Structure Of Rock Pools Along The Penobscot River, Maine, Chase R. Gagne

Electronic Theses and Dissertations

Pools of water that form in the fissures and depressions of rock outcrops, known as rock pools, are fairly common aquatic habitats that can easily be found along the rocky banks of many of Maine’s major rivers. In general, rock pools and the aquatic invertebrates inhabiting them have received little research attention and, though ubiquitous, have never been studied in Maine. My research addressed this knowledge gap by surveying 40 rock pools at four sites along the Penobscot River in Maine. The rock pools themselves had highly variable environmental characteristics and differed across sites and over time, especially in hydroperiod. …

Landscape Pattern And Wild Bee Communities In Maine, Brianne Du Clos

Electronic Theses and Dissertations

Commercial production of lowbush blueberry (Vaccinium angustifolium Aiton) in Maine relies primarily on managed honeybee hives; however, naturally occurring wild bees are more efficient pollinators of the crop. Wild bees have short foraging distances and must nest near crop fields to provide pollination services. After crop bloom, the surrounding landscape must provide sufficient forage to maintain wild bee populations for the remainder of the growing season. Lowbush blueberries in Maine are produced in a mixed-use landscape with two distinct landscape contexts. Here, we document bee communities and habitat resources (nesting and floral) in power line rights-of-way and eight land …

Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias

Electronic Theses and Dissertations

Lyme disease is caused by the bacterial spirochete Borrelia burgdorferi, which is transmitted through the bite of an infected blacklegged (deer) tick (Ixodes scapularis). Geographic invasion of I. scapularis in North America has been attributed to causes including 20th century reforestation and suburbanization, burgeoning populations of the white-tailed deer (Odocoileus virginianus) which is the primary reproductive host of I. scapularis, tick-associated non-native plant invasions, and climate change. Maine, USA, is a high Lyme disease incidence state, with a history of increasing I. scapularis abundance and northward range expansion. This thesis addresses the question: “To …

Black Soldier Fly Larvae As Value-Added Feed For Aquaculture In Maine, Joshua Villazana

Electronic Theses and Dissertations

Black soldier flies (BSF), Hermetia illucens (Linnaeus) (Diptera: Stratiomyidae) consume decaying organic waste as larvae (BSFL) and can be used for recycling a variety of biogenic wastes. BSFL can also be processed into value-added animal feeds, including those used in aquaculture. An overarching goal of this project was to obtain additional insights into BSF biology to improve their rearing and handling in future mass-production facilities serving Maine aquaculture.

We tested BSFL growth in the laboratory on seven seafood wastes from Maine fish processing facilities. Substrates potentially suitable for BSFL rearing included finfish trimmings, wet sea cucumber, dry quahog, and sea …

Flower Visitation In Relation To Pollen And Nectar Nutrition: Implications For Pollinator Habitat And Conservation, Megan E. Leach

Electronic Theses and Dissertations

Pollination of both wild and crop plants is at a crossroads; honey bee populations are experiencing losses at a higher rate than ever before, and some native bee species are declining in abundance to the point of being listed as endangered species. A few examples of these threats include pesticide exposure, habitat loss, and climate change. In response to bee population declines, conservation efforts have been initiated to increase habitat quality for bees by planting pollinator reservoirs or gardens. Plants provide nutrition to bees in the form of pollen and nectar. Several studies have shown links between higher nutritional quality …

Integrated Control Of Colorado Potato Beetle And Potato Virus Y Using Mineral Oil, Andrew K. Galimberti

Electronic Theses and Dissertations

Colorado potato beetle (Leptinotarsa decemlineata) (CPB) and Potato Virus Y (PVY) are two of the most damaging pests attacking potato crops. CPB can cause significant defoliation to potato fields and is difficult to control using insecticides because its populations rapidly develop insecticide resistance. PVY, which is transmitted non-persistently by aphids, can result in yield loss and rejection of seed potato lots. Due to its rapid mode of transmission, insecticides are often ineffective at curtailing the spread of the virus. Thus, an integrated pest management (IPM) approach is essential for both CPB and PVY control.

Mineral oil is a …

The Forgotten Cousin In Freshwater Community Ecology: Tidal Freshwater Wetlands, Jack R. Mclachlan

Electronic Theses and Dissertations

Tidal freshwaters are unique in their placement in the landscape, forming where freshwater riverine flows are sufficient to overwhelm the saline water of the incoming tide, but not strong enough to suppress tidal water-height fluctuations. Tidal freshwaters and their wetlands have been overlooked by freshwater and marine researchers alike; neither discipline considers tidal freshwaters to fall under their purview. Invertebrate communities in tidal freshwaters are thought to be species depauperate; the consensus is that they support fewer taxa than nearby non-tidal freshwaters, but little is known about how these communities are structured. This study investigated how tidal hydrology, an atypical …

Biological, Behavioral And Preventative Management Of The Invasive Insect Pest, Spotted Wing Drosophila (Drosophila Suzukii Matsumura), In Maine Lowbush Blueberry (Vaccinium Angustifolium Aiton), Gabe Alnajjar

Electronic Theses and Dissertations

This research was conducted in order to identify the potential for utilization of various management techniques against the invasive Drosophila suzukii Matsumura, commonly referred to as the spotted wing drosophila (SWD), using Maine lowbush blueberry (Vaccinium angustifolium Aiton) as a model crop system. These included evaluations of three prospective approaches often considered when developing agricultural pest management programs for novel insect pests: 1) biological control through the intended release of natural enemies, in this case entomopathogenic fungi; 2) behavioral management through mass trap deployment in order to capture and kill adult SWD, and; 3) prevention through the deployment of …

Effects Of Melatonin On Heartbeat And Possible Identification Of A Melatonin Receptor In Drosophila Melanogaster, Tricia L. Vankirk

Electronic Theses and Dissertations

Chapter 1 of this manuscript is a literature review that serves as an introduction to the entire dissertation. Chapter 2 examines the effects of the melatonin injection on heart rate and rhythmicity in Drosophila melanogaster Canton-S (wild-type) pupae and pupae bearing a variety of heart mutations. Chapter 3 investigates further the possible mechanisms of melatonin’s ability to increase heart rhythmicity without significantly affecting heart rate. A melatonin antagonist, luzindole; a high-affinity melatonin agonist, 2-iodomelatonin and RNAi techniques are used to identify a possible melatonin receptor in Drosophila melanogaster.

An appendix contains a previously published manuscript detailing experiments performed at the …

Development Of Cerceis Fumipennis For Biosurveillance Of The Emerald Ash Borer In The Northeast, Jennifer Lund

Electronic Theses and Dissertations

One method being utilized for detection of the invasive emerald ash borer, Agrilus planipennis (EAB) involves monitoring aggregations of the wasp Cerceris fumipennis for the presence of EAB in their collected prey. Currently there is little information published on its nest structure, phenology, and prey fidelity. The objectives of this research were to: i) monitor C. fumipennis male and female emergence, female prey collection, and number of colonies relative to the accumulation of degree-days (DD) throughout the summer; ii) better understand nest structure, phenology, and prey requirements of C. fumipennis; and iii) investigate C. fumipennis prey selection and fidelity. …

The Enhancement Of Wild Bees (Hymenoptera: Apoidea) For Pollination Security, Eric M. Venturini

Electronic Theses and Dissertations

The acreage of pollinator-dependent crops continues to expand across the globe. Simultaneously, honey bee hives – an annually rented commodity that growers rely on – are more expensive every year and in some cases, scarce. In response, pollinator-dependent growers seek alternative pollinators. One approach is installing bee pasture on farms, a strategy that enables systems-based farmers to become in-situ farm-scale habitat managers. This thesis first presents a review of the literature on bee pasture plantings and provides a brief overview of some methods for assessing their impacts on the pollinator community. There are three major gaps in current bee pasture …

Comparisons Of Native And Non-Native Lady Beetles: Habitat Distribution And Interactions With Prey And Competitors, Christy J. L. Finlayson

Electronic Theses and Dissertations

Lady beetles (Coleoptera: Coccinellidae), as a group, are considered beneficial because they prey on plant pests. A number of studies suggest that non-native species introduced for biological control have replaced native species in agriculture. Agricultural and non-agricultural habitats were thus surveyed in Maine to determine if native species were still dominant in some areas. In 2004 and 2005, 3,487 and 2,903 beetles were collected, respectively, with non-native species dominant in all but one habitat (coniferous forest). Native species were found in very low numbers in all habitats surveyed. Comparisons between species were then conducted to determine if differences exist that …

The Effects Of Clearcutting And Glyphosate Herbicide Use On Parasitic Wasps In Maine Forests, Kristopher J. Abell

Electronic Theses and Dissertations

Parasitic wasps (parasitoids) play an important role as natural enemies of insects and contribute substantially to world biodiversity (May, 1988), yet they have received relatively little attention outside of agricultural settings. Clearcut harvesting and herbicide (glyphosate) application are frequent and widespread disturbances in Maine forests that drastically alter the local environment. Parasitoids are particularly susceptible to disturbance for several reasons: 1) they are vulnerable to small changes in environmental conditions, 2) they occupy a high trophic level, and 3) many are host specific. However, there may be potential benefits of disturbance such as increased food resources (floral nectaries) and increased …

Effects Of Forest Management On Click Beetle (Coleoptera: Elateridae) Assemblages In The Acadian Forest Of Maine, Shelly L. Thomas

Electronic Theses and Dissertations

Click beetle (Coleoptera: Elateridae) assemblages were examined in three experiments in the Acadian forest of Maine. First, I used flight intercept traps to compare Elaterid assemblages in stands that developed after clearcut, shelterwood, and selection harvests. Click beetle richness was highest in stands managed under a selection system and lowest in stands regenerated using the clearcut method. The abundance of click beetle species was lower in stands managed by clearcutting than in stands managed using the shelterwood and selection methods. Hardwood basal area was the best environmental predictor for both species richness and species abundance. Second, I examined whether Elaterid …

European Fire Ants On Mount Desert Island, Maine: Population Structure, Mechanisms Of Competition And Community Impacts Of Myrmica Rubra L. (Hymenoptera: Formicidae), Jeffrey Garnas

Electronic Theses and Dissertations

In the early to mid-201h century, Mvrmica rubra Latreille established in various communities in Maine, mostly along the coast. Since its establishment, the ant has spread both locally via vegetative colony budding and regionally via human commerce to no fewer than 30 Maine communities, including one inland site. Studies were undertaken in the summer of 2002 to address questions of the ants' population structure in its introduced range by testing for intercolony aggression within and between local infestations. Using captive nests maintained in their original nest soil, M. rubra was tested against its close neighbors, neighbors of lorn within the …