Historical, landscape and resource influences on the coccinellid community in Missouri

"May 2014."Dissertation Supervisor: Dr. Deborah Finke.Includes vita.The diversity and abundance of native lady beetle (Coccinellidae) species in North America is declining. This decline has been attributed to the introduction and establishment of exotic lady beetles, including Coccinella septumpunctata and Harmonia axyridis. This is worrisome because coccinellids, both native and exotic, provide important biological control services in many agricultural systems. To date, most of the studies documenting negative effects of exotic species on the community of native lady beetles have been done in agricultural habitats, whereas grasslands have been suggested as potential refuge habitats for native species from the pressures of exotics. The research presented here (1) documents the impact of the introduction of exotic species on the community of native lady beetle species occurring in Missouri using a historical dataset (1930-present), showing long-term changes to the community occurring prior to exotic species establishment, (2) explores natural and agricultural grassland habitats as potential refuges for native species, finding all grasslands to be beneficial habitats for the persistence of native species, (3) explores resource availability as a mechanism that may make one grassland habitat a better refuge habitat for native coccinellid species than others, and also (4) examines the hypothesis that native coccinellid species could be actively displaced from foraging habitats by interactions with exotic lady beetle species.Includes bibliographical references (pages 102-112)

Ovipositional preference, fidelity, and fitness of \u3ci\u3eDrosophila suzukii\u3c/i\u3e in a co-occurring crop and non-crop host system

Drosophila suzukii (Matsumura) is a devastating pest of soft-skinned fruits including blackberries and raspberries. Management of this pest is focused on preventing infestation in crops, but non-crop hosts may play an important role in enabling D. suzukii to persist in the absence of cultivated hosts. Drosophila suzukii may also infest fruits of both crop and non-crop hosts concurrently. Our goals were to determine whether (1) D. suzukii prefers to oviposit in cultivated blackberry, Rubus L. subgenus rubus Watson, or American pokeweed, Phytolacca americana, a non-crop host commonly found along field edges, (2) D. suzukii prefers to oviposit into the same host from which it emerged, and (3) performance differs between D. suzukii progeny that develop in blackberries or pokeweed berries. Although the pest was able to infest both hosts at the same rate, we found that D. suzukii females emerging from pokeweed preferred to oviposit into blackberries, while females emerging from blackberry had no preference. Progeny that developed in blackberries were more fit than progeny that developed in pokeweed berries based on several measures. In field locations, cultivated blackberries and pokeweed berries only overlapped in availability for a short period of time, and infestation rates were variable between blackberries and pokeweed berries collected during that period. Nonetheless, these results suggest that noncrop hosts may facilitate the invasion of D. suzukii and perpetuate infestation of cultivated hosts under certain circumstances

Determining the Professional Development Needs of Florida Integrated Pest Management Extension Agents

With agriculture as the second largest economic industry in Florida, the state\u27s Extension agents need subject matter expertise necessary for disseminating the latest in agricultural research information to agricultural producers. Using an exploratory sequential design coupled with a Borich model, we determined the professional development needs of Florida Extension agents working in integrated pest management (IPM). Through our needs assessment, we identified 16 IPM competencies and found that the highest priority relative to needed professional development was for the competency determining pest thresholds. Extension personnel can use the list generated to assess perceptions of importance and ability level regarding IPM competencies among Extension professionals in their states

A Whole-Genome Scan for Association With Invasion Success in the Fruit Fly Drosophila Suzukii Using Contrasts of Allele Frequencies Corrected for Population Structure

Evidence is accumulating that evolutionary changes are not only common during biological invasions but may also contribute directly to invasion success. The genomic basis of such changes is still largely unexplored. Yet, understanding the genomic response to invasion may help to predict the conditions under which invasiveness can be enhanced or suppressed. Here, we characterized the genome response of the spotted wing drosophila Drosophila suzukii during the worldwide invasion of this pest insect species, by conducting a genome-wide association study to identify genes involved in adaptive processes during invasion. Genomic data from 22 population samples were analyzed to detect genetic variants associated with the status (invasive versus native) of the sampled populations based on a newly developed statistic, we called C2, that contrasts allele frequencies corrected for population structure. We evaluated this new statistical framework using simulated data sets and implemented it in an upgraded version of the program BAYPASS. We identified a relatively small set of single-nucleotide polymorphisms that show a highly significant association with the invasive status of D. suzukii populations. In particular, two genes, RhoGEF64C and cpo, contained single-nucleotide polymorphisms significantly associated with the invasive status in the two separate main invasion routes of D. suzukii. Our methodological approaches can be applied to any other invasive species, and more generally to any evolutionary model for species characterized by nonequilibrium demographic conditions for which binary covariables of interest can be defined at the population level

Population genomics of Drosophila suzukii reveal longitudinal population structure and signals of migrations in and out of the continental United States

Drosophila suzukii, or spotted-wing drosophila, is now an established pest in many parts of the world, causing significant damage to numerous fruit crop industries. Native to East Asia, D. suzukii infestations started in the United States (U.S.) a decade ago, occupying a wide range of climates. To better understand invasion ecology of this pest, knowledge of past migration events, population structure, and genetic diversity is needed. In this study, we sequenced whole genomes of 237 individual flies collected across the continental U.S., as well as several sites in Europe, Brazil, and Asia, to identify and analyze hundreds of thousands of genetic markers. We observed strong population structure between Western and Eastern U.S. populations, but no evidence of any population structure between different latitudes within the continental U.S., suggesting there is no broad-scale adaptations occurring in response to differences in winter climates. We detect admixture from Hawaii to the Western U.S. and from the Eastern U.S. to Europe, in agreement with previously identified introduction routes inferred from microsatellite analysis. We also detect potential signals of admixture from the Western U.S. back to Asia, which could have important implications for shipping and quarantine policies for exported agriculture. We anticipate this large genomic dataset will spur future research into the genomic adaptations underlying D. suzukii pest activity and development of novel control methods for this agricultural pes

Developing a Management Plan for Lebbeck Mealybug

Managing lebbeck mealybug has become an ongoing challenge in many citrus-growing areas of Florida. This pest expanded into 14 counties from 2019 to fall of 2021 and impacts both commercial and residential citrus. Management strategies can be developed to minimize the impact of lebbeck mealybug. The first step is understanding the seasonal biology of the pest.

Biological Controls for Lebbeck Mealybug

Lebbeck mealybug (Nipaecoccus viridis) was first identified in Florida citrus in 2019 in Highlands County. It has now been documented in commercial citrus groves in 11 counties and in dooryard citrus plantings in two counties. There is no quick fix to getting control over lebbeck mealybug. But researchers are making progress each week to better understand this pest, its predators and what combination of management actions are needed to support Florida citrus production

Incorporating newer tools in resets

article discusses incorporation of reflective mulch, IPCs, and kaolin sprays relative to insectide only contro

Fire Ant Management in Citrus

While there are many species of ants in Florida, the invasive fire ant (Solenopsis invicta) is the one most people are familiar with. These ants can be pests in agriculture, landscapes and structures. The pest’s ability to use a variety of habitats and resources makes it challenging to manage. Peer reviewed through UF/IFAS Citrus Research and Education Center; published in Citrus Industry Magazin

Developing management for a new snail pest

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