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Full-Text Articles in Life Sciences

Evaluation Of Medicago Truncatula Accessions For Triterpene Saponins And Their Potential Impacts On Plant Pests, Samantha Roberson Dec 2014

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 Dec 2014

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 Dec 2014

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 Dec 2014

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 (HS range: 0.46-0.63). Diploid males, …


Potential Interactions Of Early Season Herbicides And Insecticides In Cotton: Thrips Control And Plant Health, Derek Lane Clarkson Aug 2014

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 Aug 2014

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 Aug 2014

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 May 2014

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 May 2014

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 …


Letter From The Dean, Michael Vayda Jan 2014

Letter From The Dean, Michael Vayda

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.


Development Of Fad7-1 Single Mutant Arabidopsis Thaliana Plants That Are Resistant To Aphids, Kaleb L. Vaughn, Carlos A. Avila, Carmen S. Padilla-Marcia, Fiona L. Goggin Jan 2014

Development Of Fad7-1 Single Mutant Arabidopsis Thaliana Plants That Are Resistant To Aphids, Kaleb L. Vaughn, Carlos A. Avila, Carmen S. Padilla-Marcia, Fiona L. Goggin

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Aphids are a group of sap-feeding insects that attack most of the world’s crops. The loss of function of fatty acid desaturase7 (FAD7) in Solanum lycopersicum (tomato plant) induces aphid resistance that is dependent upon the accumulation of plant defense hormones such as salicylic acid (SA). Tomato lacks most of the genetic resources found in the model plant Arabidopsis (Arabidopsis thaliana). There is an analogous fad7-1 line of Arabidopsis; however, the line has a background mutation, the glabra-1 (gl1), that causes the absence of trichomes (small hairs), which are essential to plant defense. In order to study aphid resistance, a …


Contents, Discovery Editors Jan 2014

Contents, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.


Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 15 2014, Several Authors Jan 2014

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 15 2014, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.


The Introduced Dirt-Colored Seed Bug, Megalonotus Sabulicola (Hemiptera: Rhyparochromidae): New For Arkansas, S. W. Chordas Iii, C. T. Mcallister, H. W. Robison Jan 2014

The Introduced Dirt-Colored Seed Bug, Megalonotus Sabulicola (Hemiptera: Rhyparochromidae): New For Arkansas, S. W. Chordas Iii, C. T. Mcallister, H. W. Robison

Journal of the Arkansas Academy of Science

No abstract provided.


New Host And Location Record For The Bat Bug Cimex Adjunctus Barber 1939, With A Summary Of Previous Records, M. E. Grilliot, J. L. Hunt, C. G. Sims, C. E. Comer Jan 2014

New Host And Location Record For The Bat Bug Cimex Adjunctus Barber 1939, With A Summary Of Previous Records, M. E. Grilliot, J. L. Hunt, C. G. Sims, C. E. Comer

Journal of the Arkansas Academy of Science

In June 2009, 14 Rafinesque’s big-eared bats(Corynorhinus rafinesquii) were collected from an abandoned house near Shepherd, San Jacinto County, Texas. Three individuals harbored bat bugs which were subsequently identified as Cimex adjunctus Barber 1939. This is the first record of this species from C. rafinesquii. In August 2013, 10 C. rafinesquii were collected from a maternity colony in Drew County in southeastern Arkansas. Four of the bats harbored bat bugs, which were identified as C. adjunctus. This is the first record of this bat bug from Arkansas. A summary of previous state and host records of the insect is provided, …


Natural History Notes And New County Records For Ozarkian Millipeds (Arthropoda: Diplododa) From Arkansas, Kansas And Missouri, N. W. Youngsteadt, C. T. Mcallister Jan 2014

Natural History Notes And New County Records For Ozarkian Millipeds (Arthropoda: Diplododa) From Arkansas, Kansas And Missouri, N. W. Youngsteadt, C. T. Mcallister

Journal of the Arkansas Academy of Science

No abstract provided.