Life Sciences Commons^™

Potential Interactions Of Early Season Herbicides And Insecticides In Cotton: Thrips Control And Plant Health, Derek Lane Clarkson

Graduate Theses and Dissertations

Cotton growth early in the season is affected by damaging levels of thrips in many production fields in Arkansas. During this time, insecticides used to control thrips and herbicides used to control weeds are often present at the same time on the cotton plant. This research explores how various combinations of herbicides and insecticides influence thrips numbers and cotton plant growth parameters early in the growing season. Pathways evaluated included interactions between preemergence herbicides and insecticide seed treatments and interactions between common tank-mixed foliar herbicides and selected foliar insecticides. No interactions in thrips control or plant growth were observed when …

Nitrogen Management Practices And Colored Plastic Mulch Films Affecting Spider Mites And Aphids On Winter Strawberry In A High Tunnel, Kevin Philip Durden

Graduate Theses and Dissertations

Off season high tunnel strawberry production has the potential to augment income for Arkansas fruit growers during an unproductive time of the year, however management guidelines do not exist. At the University of Arkansas Agricultural Research and Extension Center in Fayetteville, AR studies were conducted to evaluate the effects of four nitrogen (46-0-0 urea fertilizer) fertigation rates (0.75, 0.50, 0.25, 0.0 kg N/day/ha) and red or black colored plastic mulch films on densities of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), numbers of parasitized cotton aphids, and fruit yield weight. Foliar and …

Evaluating Green Stink Bug Damage And Insect Abundance In Edamame, Benjamin Carroll Thrash

Graduate Theses and Dissertations

Edamame are an emerging crop in Arkansas, with 2013 planting estimates at 680 hectares. Although edamame are the same species as conventional soybeans grown in Arkansas, differences in use, maturity, and harvest may require creation and implementation of insect pest management approaches that differ from those used in conventional soybean production systems in order for a quality crop to be produced. Studies were conducted to determine a green stink bug damage-density relationship for edamame. Cages were used to confine green stink bugs on field-planted edamame at densities of 0, 2, 6, or 12 green stink bugs per cage (0, 0.55, …

Efficacy Of Rice Insecticide Seed Treatments At Selected Nitrogen Rates For Control Of The Rice Water Weevil, Lissorhoptrus Oryzophilus Kuschel, Mallory Elise Everett

Graduate Theses and Dissertations

Seed-applied insecticides are the standard control method used to prevent rice water weevil (Lissorhoptrus oryzophilus Kuschel) injury to rice (Oryza sativa L.) roots, and often results in greater yields than rice that receives no seed-applied insecticide. Yield increases from seed-applied insecticides often occur even when insect pressure is low and should not cause yield loss. The research objective was to evaluate the effect of urea-nitrogen rate and seed-applied insecticide on number of rice water weevil larvae, nitrogen uptake and rice grain yield. Six trials were conducted at the Pine Tree Research Station (PTRS) and the Rice Research Extension Center (RREC) …

Impact Of Early Infestation Of Two-Spotted Spider Mites (Tetranychus Urticae) On Cotton Growth And Yield, Luis Orellana Jimenez

Graduate Theses and Dissertations

Two-spotted spider mites (Tetranychus urticae Koch, 1836) are pests of vegetables, ornamentals, and row crops around the world. Two-spotted spider mites have become an important long-season pests of cotton, causing injury to cotton from an early vegetative stage. In the past eight years, Arkansas cotton acreage treated for spider mites has more than doubled and most of the increase has been attributed to early season infestations. Yield losses of up to 30% have been observed in other studies where spider mite infestation started at third true leaf. Because of the apparent change in this pest's population dynamics, particularly at …

Abiotic And Biotic Factors Affecting The Japanese Beetle In Arkansas, Bryan Mathew Petty

Graduate Theses and Dissertations

Japanese beetles are a relatively new pest to Arkansas. During my Ph.D. research I investigated the pathogens and environmental factors influencing Japanese beetle populations in the state. The prevalence of various pathogens and parasitoids attacking Popillia japonica were recorded annually from wild populations. Of specific interest was the microsporidian pathogen Ovavesicula popilliae, which I introduced as a biological control agent in the state. Details of the relationship between this pathogen and the Japanese beetle were investigated, including dose response, host range, and spore production. Additionally, annual abundance of the beetle in the region was recorded and tracked over the course …

The Life History Of Larinus Minutus, A Biological Control Agent Of Invasive Knapweeds, And Its Dispersal From Release Sites In Arkansas, Adam M. Alford

Graduate Theses and Dissertations

Larinus minutus Gyllenhal, a biological control agent of invasive knapweeds, has become established in several states and provinces since initial North American introduction in 1991. In order to reduce growing spotted knapweed populations in Northwest Arkansas, Larinus minutus (a biological control agent of spotted knapweed) was released annually from 2008-2011. Little is known about the larval development of this species, although the widespread use of this insect has provided research describing detailed host range and generalized life history. The speed and extent of the spread of this weevil from release sites following introduction have not been reported. This research described …

Studies On The Structure And Pathogens Of The Small Hive Beetle (Coleoptera: Nitidulidae), Natasha A. Wright

Graduate Theses and Dissertations

The small hive beetle (Aethina tumida, SHB) is an invasive pest of honey bee (Apis mellifera) colonies in the United States. The adult and larval beetles can ruin honey through fecal contamination and by vectoring a mutualistic yeast (Kodamaea ohmeri) that causes honey fermentation. These beetles also impact honey bee colonies by feeding on bee eggs, bee brood, and pollen. Severe beetle infestations can cause colonies to decline or abscond.

The SHB has been present in the United States since at least 1998. Since then, there have been several published papers on how to successfully rear these beetles. Laboratory rearing …

Influence Of Horn Flies And Breed Type On Milk Production, Calf Production Traits, Pasture Behavior, And Temperament Measurements In Beef Cattle, Angela Rene Mays

Graduate Theses and Dissertations

An experiment conducted in El Reno, Oklahoma during the fly season (May - September/October) evaluated the effects of horn flies on milk production, calf performance, and pasture behavior and temperament measurements of beef cow calf pairs. Cows (n = 53) sired by Bonsmara (BONS; n = 7), Brangus (BRAN; n = 13), Charolais (CHAR; n = 8), Gelbvieh (GELV; n = 5), Hereford (HERF; n = 12), and Romosinuano (ROMO; n = 8) from Brangus dams and their Angus sired calves (n = 51) were used in the study. Horn fly counts (HFC) and milk yield and quality estimates were …

Community Structure And Ecological Specialization In Plant-Ant Interactions, Paola Barriga

Graduate Theses and Dissertations

Positive associations among species have contributed to the maintenance of biodiversity. These interactions are typically studied in pairwise fashion where two interacting organisms are the focus. This dissertation uses network theory to analyze positive plant-ant associations in three Neotropical forests. Obligate plant-ant mutualisms were used, where plants host the ants in domatia and provide food bodies while the ants protect the plants and can feed them. A network approach was used to depict all obligate plant-ant interactions within a community. The main questions asked at the community level were: 1) Do network structure and levels of specialization change geographically and, …

Effects Of Associated Subcortical Beetles On Oviposition Behavior And Early-Stage Survival Of Sirex Nigricornis F. (Hymenoptera: Siricidae), Ace J. Lynn-Miller

Graduate Theses and Dissertations

Sirex (Hymenoptera: Siricidae) woodwasps develop within xylem of host conifers. Sirex females drill through the bark, phloem and into xylem tissues where they deposit eggs along with a symbiotic Amylostereum fungus. The presence of Amylostereum is necessary for successful development of Sirex immatures as the larvae are unable to derive adequate nutrition from xylem in the absence of the fungus. The Eurasian woodwasp, Sirex noctilio F., was discovered in northeastern North America in 2004. Sirex noctilio has caused significant economic damage in Pinus radiata D. Don plantations of the southern hemisphere, but is of little economic significance in its native …

The Biological Control Of Spotted Knapweed In The Southeastern United States, Carey R. Minteer

Graduate Theses and Dissertations

Spotted knapweed is an invasive, short-term-perennial plant that is native to Eurasia. It was accidentally introduced into North America in the early 1890's and has since spread across The United States and Canada. Spotted knapweed degrades rangelands and pastures by negatively impacting native plants, increasing soil surface runoff and stream sediment yields, and reducing soil infiltration. A biological control program for spotted knapweed using Larinus minutus (Coleoptera: Curculionidae), was initiated in Arkansas in 2008. In this dissertation I described the releases of L. minutus and investigated the adult activity in the southeastern United States (Chapter 1), investigated the effects of …

Effects Of Felled Shortleaf Pine (Pinus Echinata Mill.) Moisture Loss On Oviposition Preferences And Survival Of Sirex Nigricornis F. (Hymenoptera: Siricidae), Jessica Hartshorn

Graduate Theses and Dissertations

The European woodwasp, Sirex noctilio F. (Hymenoptera: Siricidae) utilizes pine as its host during larval development. Females drill through pine bark to deposit eggs, a symbiotic fungus, Amylostereum, and phytotoxic mucus into the tree. In their native range, these insects are not viewed as primary pests because they attack dead or dying trees. Over the last century, this woodwasp has been accidentally introduced into several countries in the southern hemisphere. Some regions have incurred millions of dollars in damage to large plantations of the widely planted pine species, radiata pine (Pinus radiata D. Don). Sirex noctilio was discovered …

Flight Period And Species Composition Of Sirex (Hymenoptera: Siricidae) And Associated Deladenus (Nematoda: Neotylenchidae) Within Arkansas Pine Forests, Danielle Keeler

Graduate Theses and Dissertations

The European woodwasp, Sirex noctilio F. (Hymenoptera: Siricidae), which is a known destructive pest of pine in the southern hemisphere was recently discovered in the eastern United States. Before we can understand how S. noctilio may affect pine forests throughout the United States, we need a better understanding of native Sirex and the role they play in the ecosystem. The objectives of this research were to 1) determine species composition and flight period for native Sirex; 2) confirm presence of parasitic nematodes, Deladenus (Nematoda: Neotylenchidae), within adult Sirex; 3) investigate Deladenus parasitism rates; 4) verify the number of Deladenus species …

The Role Of Ascorbic Acid In The Plant-Herbivore Interaction, Kelly Ann Carruthers

Graduate Theses and Dissertations

Ascorbic acid (AsA), vitamin C, is an important molecule that is vital for both human and plant health, because it aids in the detoxification of reactive oxygen species (ROS) caused by various abiotic and biotic stresses including UV, salinity, ozone, and attack from pathogens In order to understand the role of AsA in the plant-herbivore interaction, we looked at the effects of the wound-responsive hormones, jasmonate, wounding, and herbivory on AsA content. Our study is the first to directly compare the effects of wounding and jasmonates on AsA levels in plants. We looked at the effects of wounding and methyl …

Early Season Population Dynamics And Residual Insecticide Effects On Bird Cherry-Oat Aphid, Rhopalosiphum Padi In Arkansas Winter Wheat, Beven Mcwilliams

Graduate Theses and Dissertations

Bird cherry-oat aphid is a common pest of Arkansas winter wheat. This aphid vectors barley yellow dwarf virus which may cause extensive crop damage and yield loss when wheat is infested by virulent aphids in the fall. Some suggest this damage may be avoided using insecticide seed treatments if growers are unable to delay planting, as is recommended. Field population dynamics of bird cherry-oat aphid during fall 2009 and 2010 was assessed through random sampling of whole plants and pan trapping methods to evaluate aphid immigration. The field plots were divided into four subplots treated with a systemic insecticide seed …

Ozark Highland Cunaxidae (Acari: Prostigmata): Descriptions And Keys To Genera Found To Occur In The Region And A New Phylogenetic Hypothesis For The Family, Michael Joseph Skvarla

Graduate Theses and Dissertations

Fourteen genera of Cunaxidae (Acari: Prostigmata) are reported from the Ozark Highlands for the first time. Descriptions, diagnoses, and illustrated keys to genera and world species are given. Five new species are described and illustrated and an additional 6 known species are recorded from the region. The first rigorous phylogenetic hypothesis for Cunaxidae is presented. Based on morphology, it suggests the current subfamilial classification scheme does not reflect the evolutionary history of the family. Unfortunately, bootstrap values and resolution are low, suggesting the need for further indepth molecular analyses.

Chemical Ecology, Population Dynamics And Insecticide Susceptibility Of Lesser Mealworm Alphitobius Diaperinus (Panzer) (Coleoptera: Tenebrionidae), Narinderpal Singh

Graduate Theses and Dissertations

The lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), is a serious, cosmopolitan pest present in poultry production facilities, where it slows down weight gain in chicks, carries disease–causing organisms, and causes damage to poultry insulation. The first study estimated that the lesser mealworm densities in poultry litter applied to pastures were 3.5, 2.2 and 0.4 million larvae, adults and pupae, respectively, per hectare in Savoy, Arkansas. The repercussions of these adult beetles are that they often disperse to and reinfest poultry houses with the potential to vector disease to poultry, and disperse to invade human dwellings resulting in litigation. The …