Life Sciences Commons^™

Systems To Attract And Feed Pollinators In Warm-Season Lawns, Michelle Wisdom

Graduate Theses and Dissertations

Pollinating insects are responsible for the production of many agricultural crops and they require floral resources to fulfill their life-cycle. Ideally, pollinating insects will encounter a diversity of floral resources across their entire season of activity, and those floral resources can include both herbaceous and woody plant species. Managed turfgrass areas have been identified as potential locations for creating pollinator-friendly habitats. In the transition zone, where both warm- and cool-season turfgrass species are present, the persistence of herbaceous plants in warm-season turfgrasses such as bermudagrass (Cynodon spp.) and buffalograss (Buchloe dactyloides), may be affected not only by the competitive nature …

Spotted Wing Drosophila (Drosophila Suzukii) In Arkansas: Winter Morphs, Wild Hosts, And Fungal Control, Rosalee Knipp

Graduate Theses and Dissertations

Drosophila suzukii (Matsumura), or spotted wing drosophila (SWD), is an invasive fruit fly pest that was first found in the United States in 2008. Unlike native Drosophila, SWD females have a serrated ovipositor that allows them to attack ripening fruit. Since its introduction, it is unclear how and where they overwinter in Arkansas, what local hosts they utilize and what potential alternative tactics can be used to combat this pest. In states north of Arkansas, winter morphs (WM) of SWD are larger, darker pigmented, and can survive colder temperatures than SWD flies found in the summer. These WM were found …

Molecular Survey For The Honey Bee Trypanosome Parasites Crithidia Mellificae And Lotmaria Passim, Mary-Kate Williams

Graduate Theses and Dissertations

Honey bee populations have been fluctuating within recent years. No one cause has been attributed to colony fluctuations due to the theory that multiple stressors interact with one another to impact colony health. Consequently, microorganisms such as internal parasites of honey bees have been understudied as a contributor to colony health decline.

Molecular diagnostics were utilized to detect the presence of two honey bee trypanosome parasites, Crithidia mellificae and Lotmaria passim, in managed and feral honey bee populations from eight states in the United States (USA). Because studies on trypanosome infections are lacking in the USA, it is important to …

Species And Cultural Management Of Earthworms On Golf Course Turf In Arkansas And Oklahoma, Paige Elizabeth Boyle

Graduate Theses and Dissertations

As earthworms feed, they can egest soil and nutrient-rich aggregates (casts) on the soil surface. In low-cut turfgrass systems, such as golf course greens, tees, and fairways, surface casting can result in a muddy playing surface, ball roll issues, weed and pest invasion, reduced aesthetics, surface softening, and reduced photosynthesis. Because the use of pesticides for earthworm control is illegal in the U.S., earthworm casting must be managed through cultural practices. Sand topdressing is one method of earthworm control studied for use on golf courses, with the supposition being that the abrasive sand particles will deter the soft-bodied earthworms from …

Seasonal Phenology, Distribution And Treatments For Polyphagotarsonemus Latus (Banks) On Primocane-Fruiting Blackberries (Rubus L. Subgenus Rubus) In Arkansas, Jessica Anne Lefors

Graduate Theses and Dissertations

Worldwide, blackberries (Rubus L. subgenus Rubus) are an economically important crop. In 2007, Polyphagotarsonemus latus (Banks) (broad mites), were first reported damaging primocane-fruiting blackberries in Fayetteville, Arkansas. Since this time, broad mite damage to blackberries and yield loss has been reported in many states and countries. Despite the increasing reports of this blackberry pest, little is known about their population dynamics, and few treatments are available. Growers with broad mite populations need a pest management program to minimize yield loss. Therefore, there was a need to develop sampling techniques, describe broad mite seasonal phenology in blackberry fields, and determine efficacy …

Seasonality And Management Of Spotted Wing Drosophila On Berry Crops And Wild Hosts In Arkansas, Lizabeth Rubi Herrera

Graduate Theses and Dissertations

Spotted wing drosophila (SWD), Drosophila suzukii (Matsumura) is a serious invasive pest of small fruit production in North and South America and Europe since 2008. The primary control method is to apply insecticides every 5-7 days. Therefore, it is necessary to develop control tactics that are less chemical dependent to enhance an integrated approach for SWD management. The objectives of this study were to monitor SWD populations in different crop systems and adjacent landscape habitats; identify wild hosts of SWD; evaluate the effectiveness of insect exclusion netting in tunnels to prevent blackberry and blueberry infestations, and compare effects of netted …

Horizontal Transmission Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) In Soybean Fields Infested With Helicoverpa Zea (Boddie), Joseph Lee Black

Graduate Theses and Dissertations

Helicoverpa armigera Nucleopolyhedrovirus (HearNPV) is a commercially available viral biopesticide that targets Heliothines, including Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), the most damaging pest of soybean (Glycine max (L.) Merrill) in the Mid-South. Previous formulations of HearNPV have been well studied; however, no research has been published on current formulations. The first objective of this thesis was to assess the rate of horizontal transmission of HearNPV in a soybean field infested with H. zea when HearNPV was applied as a bio-insecticide, and to identify arthropods that are important obligate carriers in dissemination. HearNPV spread 200 feet in 3 fields, and was …

A Molecular Diagnostic Survey Of Pathogens And Parasites Of Honey Bees, Apis Mellifera L., From Arkansas And Oklahoma, Dylan Cleary

Graduate Theses and Dissertations

The health and viability of colonies of the honey bee, Apis mellifera, in the United States have fluctuated dramatically over the past decade. This poses a substantial threat to agricultural production in this country. Currently, no single factor has been identified for this decline. Rather, it has been suggested that the interaction between multiple biotic and abiotic stressors may be responsible. Among these factors are pesticides, habitat loss, climate and weather, parasites and pathogens, and colony management techniques. For this reason, it is important to examine the prevalence of honey bee parasite and pathogen infection at the state level in …

Bee Communities On Managed Emergent Wetlands In The Lower Mississippi Alluvial Valley Of Arkansas, Phillip Lee Stephenson

Graduate Theses and Dissertations

Native bee communities that use emergent wetlands are among the least studied systems in bee research. Most native bee species are thought to be in decline based on the loss of usable habitat across the United States. I surveyed emergent wetlands in the lower Mississippi Alluvial Valley of Arkansas during the summers of 2015 and 2016 using pan traps, blue-vane traps, and sweep nets to determine the current status of bee communities in this system. I surveyed 11 sites in 2015 and 17 sites in 2016 and found that bee communities were similar in actively versus passively managed emergent wetlands. …

The Effect Of Insects On Seed Set Of Ozark Chinquapin, Castanea Ozarkensis, Colton Zirkle

Graduate Theses and Dissertations

Ozark chinquapin (Castanea ozarkensis), once found throughout the Interior Highlands of the United States, has been decimated across much of its range due to accidental introduction of chestnut blight, Cryphonectria parasitica. Efforts have been made to conserve and restore C. ozarkensis, but success requires thorough knowledge of the reproductive biology of the species. Other Castanea species are reported to have characteristics of both wind and insect pollination, but pollination strategies of Ozark chinquapin are unknown. Experiments were conducted to determine the influence of insects on successful pollination of C. ozarkensis, as measured by production of burs and seeds. Exclosure treatments …

Flight Activity, Oviposition Pit Distribution, And Emergence Densities Of Monochamus Titillator And M. Carolinensis In The Ozark-St. Francis National Forest In Arkansas, Jake Bodart

Graduate Theses and Dissertations

Monochamus (Coleoptera: Cerambycidae) are a genus of longhorn beetles commonly known as pine sawyers. They have a worldwide distribution coincident with pines (Pinaceae) and are vectors of the pinewood nematode (Bursaphelenchus xylophilus). In the United States, there are eight known Monochamus species and they have a sympatric distribution with at least one other Monochamus species throughout their range. Monochamus are known to attack stressed, dead, and dying conifers especially pines. In the Ozark- St. Francis National Forest in Arkansas, there are two species of pine sawyers and they share this sympatric distribution observed throughout the United States, M. titillator (southern …

Survey Of Nasal Mites (Acari: Rhinonyssidae, Ereynetidae, Turbinoptidae) In Birds From Three States In The United States, Alexis Danel Hilario Perez

Graduate Theses and Dissertations

Avian nasal mites are obligate endoparasites that spend their entire life in the respiratory system of birds. In North America, bird nasal mites are represented by different unrelated families in three different orders of mites: Rhinonyssidae (Mesostigmata), Ereynetidae (Prostigmata), and the Cytoditidae and Turbinoptidae (Astigmata). The most-diverse and most-abundant family of nasal mites is the Rhinonyssidae, in which mite species may have different levels of host specificity from host orders to families or even species level. Nasal mites in North America have been surveyed in different locations, such as studies ranging from the Gulf Coast of the US to Canada. …

Influence Of Fatty Acids And Their Derivatives On Aphid Resistance In Arabidopsis And Tomato, Jiamei Li

Graduate Theses and Dissertations

Fatty acid desaturases (FADs) are enzymes that act in the chloroplast or the endoplasmic reticulum (ER) to incorporate double bonds into the acyl chains of fatty acids, and recent evidence indicates that at least one of these enzymes, FAD7, also influences plant resistance to aphids. FAD7 is an enzyme in the chloroplast that is found throughout the plant kingdom and that desaturates 16- and 18-carbon fatty acids (FAs) with two double bonds (dienoic acids) to generate FAs with three double bonds (trienoic acids). In tomato (Solanum lycopersicum) and the model plant Arabidopsis thaliana, mutants with impaired FAD7 function are more …

Emergence Phenology And Nematode Associates Of The Woodwasp, Sirex Nigricornis F. (Hymenoptera: Siricidae), In Arkansas And Mississippi Forests, Jessica Ann Hartshorn

Graduate Theses and Dissertations

Sirex nigricornis F. (Hymenoptera: Siricidae) is a native woodwasp in eastern North America that inhabits dead and dying pine trees during its univoltine development. Sirex noctilio is native to Eurasia and North Africa and was discovered in the northeastern United States in 2004 after a century of accidental introductions across the Southern Hemisphere. Since then, it has spread to seven states and southern Ontario. There is concern about its potential to negatively affect the multi-billion dollar pine timber industry of the southeastern United States. Effective monitoring tools are necessary to track the spread and establishment of S. noctilio. Deladenus siricidicola …

Integrative Taxonomy Of North American Torrent Mites (Parasitengona: Torrenticolidae: Torrenticola), Jon Ray Fisher

Graduate Theses and Dissertations

Mites are notorious for being under-studied and incomplete knowledge of distribution, life-history, and morphology are commonplace. They typically gain attention through the relatively few pest species that plague our crops, pets, or bodies. Despite representing a successful radiation with an estimated 3–5 million species, relatively few mite lineages attract research attention from non-acarologists. However, the largest radiation of all mites—Parasitengona—has potential to bridge the gap between specialists and non-specialists. Parasitengona are the butterflies of the mite world. Obvious are the bright red mites searching for pollen on concrete, or the large, furry velvet mites coming out to mate after spring …

A Comparative Study Of Medicago Truncatula Transcriptomes As They Relate To Saponin Defenses Against Insect Pests, Audra Mae Rogers

Graduate Theses and Dissertations

Triterpene saponins are a class of defensive plant-derived compounds, which have a

variety of functions including antimicrobial, insecticidal, and nematicidal activities. This

research assessed the performance of the beet armyworm, Spodoptera exigua, following ad

libero feeding on Medicago truncatula accessions differing in specialized metabolite and

saponin profiles. Insect performance did not directly relate to the foliar saponin levels in the

accessions, which was measured using HPLC mass spectrometry. Accession ESP105 had the lowest foliar saponins overall, yet had similar levels of soyasaponins compared to the other accessions. Conversely, accessions A17, PRT178, and GRC43 had high foliar saponins with particularly high …

Southeastern Monochamus And Their Interactions With Healthy Shortleaf Pine Trees And Associated Ips Grandicollis Bark Beetles, Matthew Walker Ethington

Graduate Theses and Dissertations

Insects in the genus Monochamus are medium to large-sized, wood-boring beetles whose primary hosts in the Northern Hemisphere are pine trees. These beetles interact with both conifer hosts and associated insects throughout their life history. Past research has demonstrated that Monochamus are saprophagic, but recent findings show that they may colonize healthy pine trees. To determine if southeastern Monochamus could colonize healthy pines, adult Monochamus were attracted to healthy shortleaf pine trees from May to September, 2014, using host volatiles, Ips bark beetle kairomones, and congeneric pheromones. Subsequent development of oviposited eggs from 18 host trees was monitored. The results …

An Inventory Of Endemic Leaf Litter Arthropods Of Arkansas With Emphasis On Certain Insect Groups And Diplopoda, Derek Alan Hennen

Graduate Theses and Dissertations

Endemic arthropods of Arkansas were sampled and their nomenclature and distributions were updated. The Arkansas endemic species list is updated to 121 species, including 16 species of millipedes. A study of the millipedes of Arkansas was undertaken, and resulted in the first checklist and key to all millipede species in the state. 68 species are known from Arkansas, including the genera Cylindroiulus and Polydesmus. The first state records for Ophyiulus pilosus, Cylindroiulus sp., and Ptyoiulus coveanus are reported, and new county records are reported for 16 species. This represents the first key to a state's species since 1980, and the …

Stink Bugs: Spatial Distribution, Pecan Phenological Susceptibility And Sampling Program, Brian Cowell

Graduate Theses and Dissertations

An effective management program for stink bugs (SBs) in pecan groves requires knowledge of: stages of the pecans susceptible to SB damage; strata of the tree with SB damaged nuts; a practical SB monitoring method; and, effects of landscapes contributing SBs into pecan groves.

Stink bugs produced feeding punctures in pecan shucks at all phenological stages. Pecans punctured before the dough stage drop from the tree. Kernel damage occurs in the pecans’ dough stage, whereas mature pecans are not damaged.

The pecans collected from the whole tree using the tree shaker had significantly less punctures than the pecans collected from …

Sampling Terrestrial Arthropod Biodiversity: A Case Study In Arkansas, Michael Joseph Skvarla

Graduate Theses and Dissertations

The Interior Highlands is a biodiversity hotspot, with at least 200 known endemic species, but is understudied compared to hotspots, such as the Southern Appalachians. In order to begin to rectify this issue, a nine month study was conducted from mid-March through early December at a 4 ha site at Steel Creek, Buffalo National River, in Newton County, Arkansas. Thirteen collecting methods were employed, including three colors of Lindgren funnel trap, five colors of pan trap, Malaise traps, canopy traps with upper and lower collectors, pitfall traps, and Berlese-Tullgren extraction of leaf litter, which resulted in the collection of 1311 …

Systematics Of Testudacarine Torrent Mites (Parasitengona: Torrenticolidae), Joseph Charles O'Neill

Graduate Theses and Dissertations

Thirteen new species of Testudacarus (Torrenticolidae: Testudacarinae) are described, four species are redescribed, and the status of previously problematic species are addressed. For Testudacarinae this represents the first published: 1) descriptions from multiple specimens (therefore providing ranges); 2) colored photographs; 3) explicit illustrations and discussion of sexual dimorphism within the subfamily; 4) genetic data. A comprehensive literature review is also included.

Phenology And Diversity Of Arthropod Communities In Leaf Litter, Fredericka Hamilton

Graduate Theses and Dissertations

Temperate deciduous forests produce a layer of leaf litter on the forest floor annually. This layer is dynamic, and both the composition and depth change throughout the year. The leaf litter layer is an important habitat to many arthropods since they utilize it for food, shelter from adverse environmental conditions, and protection from predators.

Two commonly encountered and diverse taxa found in the litter layer are the ground beetles (Coleoptera: Carabidae) and the ground spiders (Araneae: Gnaphosidae). Carabidae and Gnaphosidae were collected and identified on a monthly basis from April 2014 to March 2015 from the Ozark Mountains of Arkansas …

Monochamus Titillator Oviposition And Intraspecific Competition In Shortleaf Pine Bolts, Ryan Patrick Rastok

Graduate Theses and Dissertations

Monochamus titillator (Coleoptera: Cerambycidae) feed on trees in the family Pinaceae as adults and larvae. Adults feed on healthy twigs and branches and oviposit on stressed, dead, or dying trees. Prior to oviposition, females construct pits on the bark surface using their mandibles. The number of eggs laid beneath bark, where oviposition pits have been constructed, varies greatly. Developmental time and adult body size also vary greatly. I investigated oviposition and intraspecific competition with the goal of determining the degree to which various insect densities and oviposition times impact the following: 1) oviposition pit construction; 2) egg deposition; 3) emergence, …

Genetic Variation And Species Distribution Of Subterranean Termites In The Southeastern U.S. Focusing On Family Structure And The Invasive Formosan Subterranean Termite, Mark Allan Janowiecki

Graduate Theses and Dissertations

This work applies molecular genetic tools to distinguish the identity and understand the biology of termites, particularly Reticulitermes Holmgren and Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) in the southeastern U.S. Termites are important economic pests costing billions of dollars annually to Americans but also are important wood decomposers in natural settings. Molecular tools are essential for species identification because of the morphological ambiguities among species. The cryptic nest structure of subterranean termites which prevents adequate sampling makes molecular genetic tools essential to examine an entire colony.

A molecular diagnostic technique was created to differentiate Coptotermes formosanus, an invasive species in the …

Monitoring Abundance Of Ips Bark Beetles And Determining Related Tree Mortality In Arkansas And Texas, Chandler Stefan Barton

Graduate Theses and Dissertations

The abundance of the southern pine engraver beetles, Ips avulsus (Eichhoff), I. grandicollis (Eichhoff), and I. calligraphus (Germar), was monitored with pheromone-baited traps in 2012 and 2013 in Arkansas and eastern Texas. Additionally, vehicle-based and comprehensive ground-based surveys were used to estimate and confirm the amount of dead and fading trees in each trapping site. Pine engraver beetles have historically been recognized as secondary invaders of healthy trees, but observations of pine mortality in Texas and Arkansas appeared to correspond with high population densities of Ips spp. Forest sites exhibiting subjectively high or low incidence of Ips-associated mortality in Arkansas …

Phylogeny And Diversity Of Entamoeba In Cockroaches, With An Emphasis On Periplaneta Americana, Mustafa Husain Fakhri

Graduate Theses and Dissertations

While the parasitic Amoebozoan Entamoeba histolytica has been well-studied for its role in human pathogenesis, the biodiversity of invertebrate-inhabiting Entamoeba has scarcely been investigated. Using molecular methods, I searched for Entamoeba in the guts of cockroaches from four of the six Blattodean families. Entamoeba small-subunit rRNA genes were recovered from all eight species of cockroaches tested, five of which represent newly discovered hosts. Phylogenetic analysis of over 190 sequences revealed a novel and highly diverse clade of cockroach-inhabiting Entamoeba, separate from the clade predominated by vertebrate-inhabitants. These results double the known genetic diversity of Entamoeba and suggest that they may …

Evaluation Of Medicago Truncatula Accessions For Triterpene Saponins And Their Potential Impacts On Plant Pests, Samantha Roberson

Graduate Theses and Dissertations

Plants have developed numerous ways to protect themselves from microbes and insects, including producing secondary metabolites that negatively impact an invading pathogen or pest. Saponins are specialized metabolites found in many plant species and may play a role in protecting the plant. Though saponins are found in many plant species, triterpene saponins are found primarily in dicotyledons, including legumes. Medicago truncatula is a model system for studying legume biology and some accessions accumulate high concentrations of saponins. Accessions of M. truncatula known to have differing levels of saponins in both foliar and root tissues were tested for their suitability as …

Control Of Agrilus Ruficollis (Coleoptera: Buprestidae) With Insecticides And Identifying Visual Attractants For Use In A Monitoring Trap, Soo-Hoon Kim

Graduate Theses and Dissertations

The rednecked cane borer, Agrilus ruficollis (F.), is a pest of cultivated and wild blackberries in the Midwestern and Eastern parts of the United States. Feeding, mating, egg laying and development of A. ruficollis from larvae to adult only occurs on primocane, the first year vegetative growth stage of blackberries, and not on the second year fruiting stage called floricanes that die after fruiting. Damage from this pest is caused by the larva girdling the primocane and tunneling in the pith, causing the formation of a gall. Gall formation on the primocane increases the chance of winter injury and can …

Biological Control Of Red Imported Fire Ant (Solenopsis Invicta) Using Pseudacteon (Diptera: Phoridae) In Central Arkansas, Sim Mckague Barrow

Graduate Theses and Dissertations

Red imported fire ants are major pests in the southeastern United States. As a part of an integrated pest management strategy, a biological control program has been implemented which includes Pseudacteon decapitating flies. These flies are parasitoids of fire ant workers and two species of Pseudacteon are established in Arkansas: Pseudacteon tricuspis and Pseudacteon curvatus. Pseudacteon cultellatus and P. obtusus were released in the spring and fall of 2013. Despite sampling throughout 2014, establishment cannot be confirmed. Two phorid fly sampling methods, hand aspirating and sticky traps, were studied. A vacuum aspirator was compared with two sticky trap configurations. Sticky …

Population Genetics, Distributions And Phenology Of Bombus Latreille, 1802 And Xylocopa Latreille, 1802 (Hymenoptera: Apidae), Amber Dawn Tripodi

Graduate Theses and Dissertations

This work addresses multiple knowledge gaps in bee ecology, population health and phylogeography in order to provide insights into the changing distributions of native bees. A comparison of Arkansas bumble bee records mirrors range-wide surveys, with records of stable species (Bombus bimaculatus Cresson, 1863 and B. impatiens Cresson, 1863) increasing three-fold, and records of the declining B. pensylvanicus (DeGeer, 1773) dropping to 60% of historical levels. However, nationally-recommended conservation-genetics tools did not mirror these results on a regional level. Stable and declining species had equivalent genetic diversity in samples from Arkansas and Tennessee (H_S range: 0.46-0.63). Diploid males, …