Digital Commons Network^™

Evaluation Of Herbicides For Saltcedar Control In Southwest Kansas, W. H. Fick

IGC Proceedings (1997-2023)

Saltcedar is an invasive species along some of the major rivers and tributaries in Kansas. The objective of this study is to determine control of saltcedar in southwestern Kansas using herbicides applied to individual trees as cut-stump, basal, and foliar treatments. Cut-stump treatments were applied in 2004-2010 during the months of April or May. Basal applications with 10% triclopyr in diesel were applied between 2007-2021 during the months of August through early October. Foliar treatments were applied during 2008-2021 using 467 L/ha spray volumes during August through early October. Chi square analysis at P < 0.05 was used to compare treatments. In initial studies, imazapyr (Arsenal) at 10% v/v in water, triclopyr (Remedy) at 10% v/v in diesel, and undiluted triclopyr (Pathfinder II) provided 80- 100% control of saltcedar, and were more effective than triclopyr + 2,4-D (Crossbow) applied as a 4% v/v solution in diesel (60% control). During 2008-2010, 10% imazapyr, 50% glyphosate, glyphosate + imazapyr (0.5% + 0.5%), triclopyr at 10 or 25%, and a mixture of triclopyr + fluroxypyr (PastureGard) at 25% all provided greater than 91% control of saltcedar. Basal bark control using 10% v/v triclopyr in diesel averaged 72% control. Foliar applications with 0.5 or 1% imazapyr and 0.5% + 1% imazapyr + glyphosate all provided greater than 84% control of saltcedar treated in 2008-2011. Imazapic (Plateau) at 1% was first compared with 1% imazapyr during 2014-2016 with both treatments providing about 80% control. During 2017-2021, 1% imazapyr (82% control), 1% imazapic (79% control), and 0.5% + 0.5% imazapyr + glyphosate (92% control) were all more effective than a combination of aminopyralid (Milestone) + triclopyr applied at 239 g/L + 359 g/L (42% control). Herbicides can be applied as cutstump, basal bark, or foliar treatments for the control of saltcedar.

Assessing The Usefulness Of Senna Obtusifolia, An Invasive Plant Species In West Africa Rangelands, A. Zaré, O. Ouédraogo, A. Linstädter

IGC Proceedings (1997-2023)

Senna obtusifolia is a less appreciated plant species. Its invasion has led to the disappearance of several herbaceous species of interest in West Africa rangelands. As adaptation strategy, people use it to substitute for those that have disappeared. This study aimed to assess the importance of this species for animal and local ethnic groups according to two contrast climate zones in Burkina Faso. Ethnobotanic survey mixed with direct observations on the field were conducted. Three hundred (300) people from height (8) ethnic groups were interviewed. The survey technique was semi-structured interviews using a previously tested semi-structured questionnaire. At the early …

Soil Biology And The Emergence Of Adventive Grassland Ecosystems, T. R. Seastedt

IGC Proceedings (1997-2023)

The last few years have seen an explosion of information on the responses and feedbacks of soil biota to species and environmental changes. Soil biologists, plant ecologists, and biogeochemists have been searching for patterns, generality and predictability in these relationships. A few brave souls have had the courage to assemble comprehensive assessments of soil biology in our rapidly changing world. Several years ago, I reviewed Wardle’s (2002) book emphasising the links between above- and belowground components of ecosystems. That activity – as well as the present one – provided me with the opportunity to survey recent findings in soil biology. …

Non-Native Non-Apis Bees Are More Abundant On Non-Native Versus Native Flowering Woody Landscape Plants, Daniel A. Potter, Bernadette M. Mach

Entomology Faculty Publications

Urban ecosystems can support diverse communities of wild native bees. Because bloom times are conserved by geographic origin, incorporating some non-invasive non-native plants in urban landscapes can extend the flowering season and help support bees and other pollinators during periods when floral resources from native plants are limiting. A caveat, though, is the possibility that non-native plants might disproportionately host non-native, potentially invasive bee species. We tested that hypothesis by identifying all non-native bees among 11,275 total bees previously collected from 45 species of flowering woody landscape plants across 213 urban sites. Honey bees, Apis mellifera L., accounted for 22% …

Feature Papers In Horticulturae, Douglas D. Archbold

Horticulture Faculty Publications

No abstract provided.

Effects Of Parthenium Hysterophorus On Grassland Community In Nyando Sub-County, Kisumu County, Kenya, B. M. Mutua, W. Chiuri

IGC Proceedings (1997-2023)

Parthenium hysterophorus is an invasive alien species native to South and Central America. The plant is ranked as one of the most dreaded weeds of the world. Parthenium hysterophorus affects grassland community through the release of allelochemicals that inhibit the germination and growth of grass species. However, little is known about its effects on native grassland community in Nyando sub-county of Kenya. Therefore, this study sought to investigate the effects of P. hysterophorus on grass species, livestock production and its control. A total of 121 farm household heads were interviewed using semi-structured interview schedules. Descriptive analysis and the T-test at …

Forest Development Over A Twenty-Year Chronosequence Of Reforested Urban Sites, Kenton L. Sena, Zachary J. Hackworth, John M. Lhotka

Lewis Honors College Faculty Publications

Urbanization causes a variety of negative ecological impacts, impairing forests, streams, and other ecosystems. While urban forests are the subject of increasing research attention, planted urban forests are less well-understood than remnant forests; however, these systems may be distinct in terms of ecosystem structure and function. The current study investigates a chronosequence of reforested urban sites in Lexington, KY, USA, with a focus on overstory and understory woody plant community characteristics. Monitoring plots were established in each of the 20 sites; tree height, dbh, and species were surveyed for the overstory, and species and height were surveyed for the understory. …

Healthy Trees – Healthy People: A Model For Engaging Citizen Scientists In Exotic Pest Detection In Urban Parks, Heather Norman-Burgdolf, Lynne K. Rieske

Dietetics and Human Nutrition Faculty Publications

Healthy Trees – Healthy People (HT-HP) is an outreach and education program created to enlist and train participants in exotic pest detection while providing them with structured opportunities to connect with urban nature and increase their physical and emotional health. HT- HP creates infrastructure to increase engagement by the urban populace in the urban tree canopy. The program solicits participants to engage in an 8-week intervention designed to expand capacity to detect non-native insect pests and pathogens, while increasing physical activity, raising awareness of healthy lifestyle choices, and improving the health of participants. Program participants were trained in tree and …

Comparison Of Native And Non-Native Predator Consumption Rates And Prey Avoidance Behavior In North America And Europe, Ayse Gül Ünlü, John J. Obrycki, Roman Bucher

Entomology Faculty Publications

Novel predator–prey interactions can contribute to the invasion success of non-native predators. For example, native prey can fail to recognize and avoid non-native predators due to a lack of co-evolutionary history and cue dissimilarity with native predators. This might result in a competitive advantage for non-native predators. Numerous lady beetle species were globally redistributed as biological control agents against aphids, resulting in novel predator–prey interactions. Here, we investigated the strength of avoidance behavior of the pea aphid (Acyrthosiphon pisum) toward chemical cues of native lady beetles and non-native Asian Harmonia axyridis and European Coccinella septempunctata and Hippodamia variegata …

Invasive Paper Wasp Turns Urban Pollinator Gardens Into Ecological Traps For Monarch Butterfly Larvae, Adam M. Baker, Daniel A. Potter

Entomology Faculty Publications

Invasive species can be particularly disruptive when they intersect with organisms of conservation concern. Stabilizing the declining eastern migratory population of monarch butterflies (Danaus plexippus) is projected to require extensive habitat restoration across multiple land use sectors including metropolitan areas. Numerous conservation programs encourage urban citizens to plant gardens with milkweeds, the obligate larval host plants of the monarch. Here, we show that predation by Polistes dominula, an invasive paper wasp that is particularly abundant in urban settings, can turn such sites into ecological traps for monarch larvae. Polistes dominula was the predominant paper wasp seen foraging …

Unpalatable Perennial Grass Invasion In Central-East Argentina Native Grasslands: Processes, Implications And Recovery, Roberto A. Distel

IGC Proceedings (1997-2023)

In temperate semiarid central-east Argentina, unpalatable perennial grasses (UPG) have been steadily invading native grasslands formerly dominated by palatable perennial grasses (PPG). The objective of this contribution is to provide a synthesis of underlying processes and implications of UPG invasion, as well as recovery strategies. Results have shown that heavy selective grazing on PPG reduces their superior competitive ability. Gaps formed due to reduced competition by PPG provide safe sites for UPG establishment. The development of large, long-lived tussock of UPG, in combination with high standing crop accumulation, impairs PPG establishment even in absence of grazing. UPG produce sclerophyllous tissues, …

Japanese Beetles’ Feeding On Milkweed Flowers May Compromise Efforts To Restore Monarch Butterfly Habitat, Adam M. Baker, Daniel A. Potter

Entomology Faculty Publications

The eastern North American migratory population of monarch butterflies (Danaus plexippus) is in serious decline. Habitat restoration, including adding millions of host plants to compensate for loss of milkweed in US cropland, is a key part of the international conservation strategy to return this iconic butterfly to sustainable status. We report here that Popillia japonica, a polyphagous, invasive beetle, aggregates and feeds on flowers of Asclepias syriaca, the monarch’s most important larval food plant, reducing fruiting and seed set by >90% and extensively damaging milkweed umbels in the field. The beetle’s ongoing incursion into the monarch’s …

Reference Gene Selection For Rt-Qpcr Analysis In Harmonia Axyridis, A Global Invasive Lady Beetle, Xiaowei Yang, Huipeng Pan, Ling Yuan, Xuguo Zhou

Entomology Faculty Publications

Harmonia axyridis is a voracious predator, a biological control agent, and one of the world most invasive insect species. The advent of next-generation sequencing platforms has propelled entomological research into the genomics and post-genomics era. Real-time quantitative PCR (RT-qPCR), a primary tool for gene expression analysis, is a core technique governs the genomic research. The selection of internal reference genes, however, can significantly impact the interpretation of RT-qPCR results. The overall goal of this study is to identify the reference genes in the highly invasive H. axyridis. Our central hypothesis is that the suitable reference genes for RT-qPCR analysis …

Coleopteran Communities Associated With Forests Invaded By Emerald Ash Borer, Matthew B. Savage, Lynne K. Rieske

Entomology Faculty Publications

Extensive ash mortality caused by the non-native emerald ash borer alters canopy structure and creates inputs of coarse woody debris as dead and dying ash fall to the forest floor; this affects habitat heterogeneity; resource availability; and exposure to predation and parasitism. As EAB-induced (emerald ash borer-induced) disturbance progresses the native arthropod associates of these forests may be irreversibly altered through loss of habitat; changing abiotic conditions and altered trophic interactions. We documented coleopteran communities associated with EAB-disturbed forests in a one-year study to evaluate the nature of these changes. Arthropods were collected via ethanol-baited traps on five sites with …

The Invasive Med/Q Bemisia Tabaci Genome: A Tale Of Gene Loss And Gene Gain, Wen Xie, Xin Yang, Chunhai Chen, Zezhong Yang, Litao Guo, Dan Wang, Jinqun Huang, Hailin Zhang, Yanan Wen, Jinyang Zhao, Qingjun Wu, Shaoli Wang, Brad S. Coates, Xuguo Zhou, Youjun Zhang

Entomology Faculty Publications

Background: Sweetpotato whitefly, Bemisia tabaci MED/Q and MEAM1/B, are two economically important invasive species that cause considerable damages to agriculture crops through direct feeding and indirect vectoring of plant pathogens. Recently, a draft genome of B. tabaci MED/Q has been assembled. In this study, we focus on the genomic comparison between MED/Q and MEAM1/B, with a special interest in MED/Q’s genomic signatures that may contribute to the highly invasive nature of this emerging insect pest.

Results: The genomes of both species share similarity in syntenic blocks, but have significant divergence in the gene coding sequence. Expansion of cytochrome P450 monooxygenases …

Tracking A Tree-Killer: Improving Detection And Characterizing Species Distribution Of Phytophthora Cinnamomi In Appalachian Forests, Kenton L. Sena

Theses and Dissertations--Plant and Soil Sciences

Phytophthora cinnamomi is a soil-borne oomycete pathogen causing root rot in susceptible host species. P. cinnamomi is thought to have originated in Southeast Asia, but has since been introduced to many regions around the world, where it causes dramatic declines in many forest tree species. In the eastern US, the primary susceptible tree species of concern are American chestnut (Castanea dentata), white oak (Quercus alba), and shortleaf pine (Pinus echinata). American chestnut, functionally eliminated in the early 1900s by the rapidly acting chestnut blight (Cryphonectria parasitica), has been the subject of decades-long …

A Window Of Opportunity: Subdominant Predators Can Use Suboptimal Prey, Kelly A. Jackson, Joshua S. Mccord, Jennifer A. White

Entomology Faculty Publications

Introduced species have been linked to declines of native species through mechanisms including intraguild predation and exploitative competition. However, coexistence among species may be promoted by niche partitioning if native species can use resources that the invasive species cannot. Previous research has shown that some strains of the aphid Aphis craccivora are toxic to a competitively dominant invasive lady beetle, Harmonia axyridis. Our objective was to investigate whether these aphids might be an exploitable resource for other, subdominant, lady beetle species. We compared larval development rate, survival, and adult weight of five lady beetle species in no-choice experiments with …

A Non-Native Forest Invader Alters Forest Structure And The Associated Arthropod Community, Matthew B. Savage

Theses and Dissertations--Entomology

The emerald ash borer (EAB, Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is a non-native wood boring beetle that is causing extensive ash (Fraxinus spp.) mortality in eastern North America, affecting both urban and wildland forests and drastically altering forest structure and composition. As EAB-induced ash mortality progresses, native arthropod associates of ash forests are impacted by the effects of rapid and broad scale tree mortality. These include loss of food source, increased canopy gap formation, alterations in litter inputs causing shifting temperature and moisture regimes on the forest floor, and significant accumulation of coarse woody debris.

I assessed the sub-canopy …

Benthic Collector And Grazer Communities Are Threatened By Hemlock Woolly Adelgid-Induced Eastern Hemlock Loss, Joshua K. Adkins, Lynne K. Rieske

Entomology Faculty Publications

Eastern hemlock (Tsuga canadensis (L.) is a foundation species in eastern North America where it is under threat from the highly invasive, exotic hemlock woolly adelgid (Adelges tsugae). Eastern hemlock is especially important in riparian areas of Central and Southern Appalachia, so we compared the spatial and temporal composition of benthic collector-gatherers, collector-filterers, and grazers in headwater streams with hemlock-dominated riparian vegetation to those with deciduous tree-dominated riparian vegetation to evaluate the extent to which adelgid-induced hemlock loss could influence composition and abundance of these two functional feeding groups. We found differences in benthic invertebrate abundance and …

Efficacy Of Dormant Season Herbicide Application On Control Of Japanese Honeysuckle (Lonicera Japonica) For Habitat Restoration In Kentucky, Jason L. Weese

Theses and Dissertations--Forestry and Natural Resources

Kentucky’s disappearing native grassland communities provide habitat for native flora and fauna. A study was conducted to compare the efficacy of herbicides in control of the invasive Japanese honeysuckle (Lonicera japonica) applied at times when most native species are dormant. Six herbicide mixtures (glyphosate, glyphosate + imazapyr, glyphosate + imazapic, imazapyr, triclopyr + difluphenzopyr, and metsulfuron + difluphenzopyr) were applied in three seasons to assess the effect of application timing of each mixture on honeysuckle control. Herbicides were applied with a CO² pressurized sprayer at three sites in a randomized complete block design. Pretreatment sampling indicated that …

Effects Of Plant Virus And Its Insect Vector On Encarsia Formosa, A Biocontrol Agent Of Whiteflies, Xiaoyuan Liu, Wensheng Xiang, Xiaoguo Jiao, Youjun Zhang, Wen Xie, Qingjun Wu, Xuguo Zhou, Shaoli Wang

Entomology Faculty Publications

In this study, we investigated the tritrophic interactions among a persistently transmitted plant virus, Tomato yellow leaf curl virus (TYLCV), its insect vector, the sweetpotato whitefly Bemisia tabaci, and a parasitoid, Encarsia formosa Gahan, one of the most extensively used biological control agents. As an emerging invasive pest worldwide, the two most damaging whiteflies are B. tabaci B and Q cryptic species. On healthy tomato plants, parasitoid-induced mortality was significantly higher in B. tabaci B than in Q. In contrast, similar mortality levels of B and Q were observed on TYLCV-infected plants. A higher rate of parasitism was consistently observed …

Bemisia Tabaci Q Carrying Tomato Yellow Leaf Curl Virus Strongly Suppresses Host Plant Defenses, Xiaobin Shi, Huipeng Pan, Hongyi Zhang, Xiaoguo Jiao, Wen Xie, Qingjun Wu, Shaoli Wang, Yong Fang, Gong Chen, Xuguo Zhou, Youjun Zhang

Entomology Faculty Publications

The concurrence of tomato yellow leaf curl virus (TYLCV) with the spread of its vector Bemisia tabaci Q rather than B in China suggests a more mutualistic relationship between TYLCV and Q. Here, we investigated the hypothesis that viruliferous B and Q have different effects on plant defenses. We found the fecundity of nonviruliferous B, nonviruliferous Q, viruliferous Q and viruliferous B was 11.080, 12.060, 10.760, and 11.220 respectively on plants previously attacked by the other biotype, however, on their respective noninfested control leaves fecundity was 12.000, 10.880, 9.760, and 8.020 respectively. Only viruliferous B had higher fecundity on viruliferous …

Does Fungal Endophyte Infection Improve Tall Fescue’S Growth Response To Fire And Water Limitation?, Sarah L. Hall, Rebecca L. Mcculley, Robert J. Barney, Timothy D. Phillips

Plant and Soil Sciences Faculty Publications

Invasive species may owe some of their success in competing and co-existing with native species to microbial symbioses they are capable of forming. Tall fescue is a cool-season, non-native, invasive grass capable of co-existing with native warm-season grasses in North American grasslands that frequently experience fire, drought, and cold winters, conditions to which the native species should be better-adapted than tall fescue. We hypothesized that tall fescue’s ability to form a symbiosis with Neotyphodium coenophialum, an aboveground fungal endophyte, may enhance its environmental stress tolerance and persistence in these environments. We used a greenhouse experiment to examine the effects …

An Assessment Of The Invasive Poison Hemlock And Its Insect Associates In Kentucky, Christine D. Allen

Theses and Dissertations--Entomology

Poison hemlock, Conium maculatum (Apiaceae), is an invasive plant in North America with a unique toxic chemistry. Previous research on this plant has focused on identifying herbivores as potential biological control agents or describing the toxic plant alkaloids. However, none have examined the role of higher trophic levels in the food web surrounding poison hemlock. Generalist predators and food web interactions are an important component of studies investigating invasion effects, as plant or animal introductions can alter ecosystem functioning. In this study, predators in poison hemlock were sampled at the foliar and epigeal levels, resulting in 956 Carabidae and 321 …