Entomology Commons^™

Population Dynamics Of The Diamondback Moth And Its Parasitoids In Zimbabwe, Rudo Sithole, Casper Nyamukondiwa, Peter Chinwada, Bernhard Lohr

All Peer-Reviewed Publications

Temporal population dynamics of the diamondback moth (DBM), Plutella xylostella (L.) and its parasitoids were studied for a continuous 13-months period at two sites in Zimbabwe, vis Henderson and Mutoko. Our results showed that mean DBM numbers of 2.2 and 2.9 per plant for Henderson and Mutoko, respectively were not significantly different (p = 0.12). At Henderson, the DBM numbers achieved a pre-winter peak in February and a post-winter peak in October, while at Mutoko the pre-winter and post-winter peaks were reached a month earlier, in January and September, respectively. A total of four parasitoid species, comprising Cotesia vestalis, Oomyzus …

Vertical Connectivity Influences Secondary Production, Community Diversity, And Resilience In An Ozark Stream, Nathan C. Dorff

Graduate Theses/Dissertations

The hyporheic zone, a key component of stream vertical connectivity, supports stream function (e.g., nutrient regeneration) and provides habitat for aquatic biota. The Ozark Highlands ecoregion contains gravel-bed streams that have extensive hyporheic zones and that are subject to recurrent flash floods. I sampled Leuctra tenuis(Pictet) nymphs from the hyporheic habitat (30-45 cm below the streambed) in a gravel-bed reach and an intermittent tributary of an Ozark stream from early instar to adult emergence. Concurrently, I sampled benthic insects in two reaches of the same stream that differed primarily in amount of hyporheic habitat (bedrock vs. gravel) and monitored …

Recovery Of Domestic Behaviors By A Parasitic Ant (Formica Subintegra) In The Absence Of Its Host (Formica Subsericea), Amber Nichole Hunter

Graduate Theses/Dissertations

Dulosis is a type of social parasitism in which a parasitic ant has become dependent on captured workers (hosts) of a closely related species. Dulosis can be either facultative or obligate depending on the degree of dependence on host workers. As parasites become more specialized over evolutionary time, their domestic abilities degenerate until they become unable to survive without the host. However, the ‘lost’ behaviors may display some degree of recovery when host workers are unavailable to do the tasks. The Formica sanguinea group consists of 12 species of parasitic ants, which are all traditionally considered to be facultative parasites. …

Using Pseudo Nomarski Contrast To Study Hemocytes Of Galleria Mellonella, Westley David Peterson

Graduate Theses/Dissertations

Differentiation of insect hemocytes requires microscopes equipped with differential interference contrast (DIC), s.c. Nomarski’s contrast. However, the high price of DIC limits speed and efficacy of hemocyte studies. For my thesis, I developed two low cost microscope sets equipped with custom oblique illumination filters. The oblique illumination filters, that I produced, provided high quality images comparable with those produced by DIC, for a fraction of the cost and allowed me to train laboratory personnel quickly. Microscopes with these oblique illumination filters were used in studies of spherulocytes and for rapid screening of plant essential oils to impair insect immune system. …

From Spinning Silk To Spreading Saliva: Mouthpart Remodeling In Manduca Sexta (Lepidoptera: Sphingidae), Istvan Miko, Sarthok Rasique Rahman, Anne C. Jones, Mark A. Townley, Brandon Gominho, Sulav Paudel, S David Stupski, Heather M. Hines, Rudolf J. Schilder

Biological Sciences

As a model organism, the tobacco hornworm Manduca sexta (Linnaeus 1763) has contributed much to our knowledge of developmental processes in insects, and major developmental changes between different larval instars are generally well understood. Second and later instars of M. sexta do not produce silk, and their spinneret and accessory labial glands (=Lyonet’s glands), structures thought to be key players in silk production in other lepidopterans, are highly reduced. To our knowledge, mouthparts and labial gland morphology of the silk-producing first instar have never been described. In this study, we compared the mouthpart morphology and transcriptome profile of first and …

Physiological Characterization Of Inward Rectifier Potassium (Kir) Channels In Insect Neural Systems, Rui Chen

LSU Master's Theses

A complete understanding of the physiological pathways critical for proper function of the insect nervous system is still lacking. The recent development of potent and selective small-molecule modulators of insect inward rectifier potassium channels has enabled the interrogation of the physiological role and toxicological potential of Kir channels within various insect tissue systems. Therefore, we aimed to highlight the physiological and functional role of neural Kir channels in the central nervous system, muscular system, and neuromuscular system through pharmacological and genetic manipulations. Our data provide significant evidence that Drosophila neural systems rely on the inward conductance of K+ ions for …

Effect Of Larval Density And Substrate Quality On The Wing Geometry Of Stomoxys Calcitrans L. (Diptera: Muscidae), Steve B.S. Baleba, Daniel Masiga, Baldwyn Torto, Christopher W. Weldon, Merid N. Getahun

All Peer-Reviewed Publications

Background: In insects, oviposition decisions may lead to egg deposition in substrates with different larval density and nutritional levels. Individuals developing in such substrates may present plasticity in their phenotype. Here, we investigated the effect of two factors related to oviposition decisions, namely larval density and substrate quality, on the wing size and wing shape of the stable fly, Stomoxys calcitrans L. (Diptera: Muscidae). Methods: We reared S. calcitrans larvae at different densities (5, 15 and 25) and on different substrates (camel, cow, donkey and sheep dung). For each fly that emerged, we recorded body weight, and detached, slide-mounted and …

Mesopredator Distribution, Abundance And Potential Competition With The American Burying Beetle (Nicrophorus Americanus) At Fort Chaffee Joint Maneuver Training Center, Karisa Fenton

Theses and Dissertations from 2019

The American burying beetle (Nicrophorus americanus, hereafter ABB) was listed as an endangered species in 1989 and many hypotheses have been developed to explain their rangewide decline. I investigated the carcass competition hypothesis that implicates increased competition between vertebrate scavengers and ABBs for appropriate-sized carcasses as a cause for ABB decline. Predators of medium size that occupy an intermediate trophic level (hereafter mesopredators) are potential competitors for carcasses. I used camera trapping to assess mesopredator abundances in nine different habitats at Fort Chaffee Joint Maneuver Training Center (FCJMTC) in western Arkansas because this area supports the largest known population of …

Reproductive Character Displacement In Calopteryx Aequabilis And C. Maculata: Improving Species Recognition Through The Divergence Of Male Mating Preferences, Melissa Encinias

Masters Theses, 2010-2019

An ongoing evolutionary question is how co-occurring species maintain reproductive barriers when they are morphologically, behaviorally, and ecologically similar. Without geographic isolation, traits involved in species recognition may be under selection to enhance reproductive barriers. Exaggerated trait differences between species in sympatric populations may reflect selection to reduce misdirected mating between species, or reproductive character displacement. While this phenomenon is widely recognized as an important stage in the speciation process, there is little direct evidence of this process in nature. In two North American damselfly species, Calopteryx aequabilis and C. maculata, wing pigmentation is sexually dimorphic and also shows …

The Interface Between Invasive Species And The Increased Incidence Of Tick-Borne Diseases, And The Implications For Federal Land Managers, Ed Clark, Janis Mcfarland, Blaine Parker, Slade Franklin

National Invasive Species Council

Includes information on the dynamics of tick-borne disease, factors affecting the occurrence and density of ticks, matrices of ties between habitat, human activities, invasive plants, and ticks, federal resources and programs related to ticks and vector-borne disease in the United States, with references and an annotated bibliography of literature on ticks, vector-borne diseases, and invasive species.

Hexapod Herald - Vol. 31, No. 2, May 2019

Hexapod Herald and Other Entomology Department Newsletters

Congratulations -- Meeting News -- Welcome -- Publications -- Grants -- Faculty News -- Outreach -- Student News -- Busy as a Bee -- Distinguished Alumni Recognition -- Entomology Department Alumni Dinner

Nebline, May 2019

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

25 Years of Earth Wellness Festival: A Generation of Students Have Learned Value of Environmental Resources

Malcolm 4th Graders Learn About Healthy Choices

Recipe of the Month

2019 Cash Rent Survey

Bagworm Control in Windbreaks

Choosing the Best Bug Spray to Protect Your Family From Mosquitoes and Ticks

2019 Herb of the Year

Garden Guide Things to Do This Month

Children and Mindful Eating

Heart of 4-H Volunteer Award: Susan Martin

Babysitting Training, June 18

4-H Announcements for 4-H'ers and Volunteers

Clover College

Upcoming Landscape Workshops

Extension News: New Domestic Water and Wastewater Extension Associate

Extension News: Two New Interns …

The Impact Of Fall Armyworm, Spodoptera Frugiperda (J.E. Smith), Feeding And Mechanical Defoliation On Growth And Yield Of Rice, Oryza Sativa (L.), Layton Denman Mccullars

Graduate Theses and Dissertations

The fall armyworm, Spodoptera frugiperda (J.E. Smith), (FAW) is a serious pests of many crops, and can be observed feeding throughout the entire growing season on rice, Oryza sativa, (L.). A new defoliation based threshold would help rice growers and consultants make more economically sound decisions for FAW. Work from this thesis focuses on determining the amount of damage caused by FAW feeding at different growth stages and effective insecticide seed treatments for controlling this pest.

Field plots were mechanically defoliated to determine grain yield loss across multiple growth stages and defoliation percentages. Results indicated that defoliation in late vegetative …

Geospatial Analysis Of Rickettsial Species, Amy Frank

Animal Science Undergraduate Honors Theses

Rickettsia species are obligate intracellular, arthropod-borne bacteria with a potential to cause multiple diseases including Rocky Mountain spotted fever (RMSF). Fleas, mites, and ticks serve as vectors for Rickettsia, but ticks are the primary vector of interest. RMSF and other rickettsial diseases have continued to gain importance in both human and veterinary medicine as RMSF is the most common tick-borne disease within the United States according to the Lyme and Tick-Borne Disease Research Center. A statewide citizen science project was utilized to determine the prevalence of Spotted Fever Group (SFG) Rickettsia in Arkansas. This project yielded results in 64 …

Do Enallagma Exsulans From Streams And Lakes Show Patterns Of Divergence?, Savannah Rae Graham

Graduate Theses and Dissertations

Divergent selection across heterogenous environments could lead to adaptive divergence in populations resulting in potential local adaption. These populations have phenotypic differences that are fitness related and make native individuals more fit than non-native individuals. My research focuses on a species of damselfly, Enallagma exsulans, to explore local adaptation and morphological differences as a result of divergent selection or plasticity. My first study explored potential local adaptation of wild caught stream and lake E. exsulans using a reciprocal transplant design, a classic approach for this objective. The stream and lake sites chosen were on a small spatial scale allowing for …

Indole Sensitivity In Various Insect Herbivores., Rakhi Patel

College of Arts & Sciences Senior Theses

When plants in nature are attacked by herbivores, they frequently release airborne volatiles. These herbivore-induced plant volatiles (HIPVs) help plants defend themselves against herbivore attack by calling in natural enemies, but HIPVs may also be directly toxic to herbivores. Indole (C₈H₇N) is a common HIPV that is toxic to caterpillars, but its relative toxicity to different caterpillars has not been explored. I tested the toxicity of indole on six caterpillar species (Spodoptera frugiperda, Trichoplusia ni, Spodoptera exigua, Anticarsia gemmatalis, Heliothis virescens, and Helicoverpa zea). Results show that indole is …

Biogeography Of Endemic Dragonflies Of The Ozark-Ouachita Interior Highlands, Wade Alexander Boys

Graduate Theses and Dissertations

A common pattern across many taxonomic groups is that relatively few species are widespread while the majority are restricted in their geographic ranges. Such species distributions are used to inform conservation status, which poses unique challenges for rare or cryptic species. Further, priority status is often designated within geopolitical boundaries, which may include only a portion of a species range. This, coupled with lack of distributional data, has resulted in species being designated as apparently rare throughout some portions of their range, which may not accurately reflect their overall conservation need. The Interior Highlands region of the central United States …

Spatial Patterns And Sequential Sampling Plans For Estimating Densities Of Stink Bugs (Hemiptera: Pentatomidae) In Soybean In The North Central Region Of The United States, Daniela T. Pezzini, Christina D. Difonzo, Deborah L. Finke, Thomas Hunt, Janet J. Knodel, Christian H. Krupke, Brian P. Mccornack, Andrew P. Michel, Roger D. Moon, Christopher R. Philips, Adam J. Varenhorst, Robert Wright, Robert Koch

Department of Entomology: Faculty Publications

Stink bugs are an emerging threat to soybean (Fabales: Fabaceae) in the North Central Region of the United States. Consequently, region-specific scouting recommendations for stink bugs are needed. The aim of this study was to characterize the spatial pattern and to develop sampling plans to estimate stink bug population density in soybean fields. In 2016 and 2017, 125 fields distributed across nine states were sampled using sweep nets. Regression analyses were used to determine the effects of stink bug species [Chinavia hilaris (Say) (Hemiptera: Pentatomidae) and Euschistus spp. (Hemiptera: Pentatomidae)], life stages (nymphs and adults), and field locations (edge …

Western Corn Rootworm Pyrethroid Resistance Confirmed By Aerial Application Simulations Of Commercial Insecticides, Dariane Souza, Bruno C. Vieira, Bradley K. Fritz, Wesley C. Hoffmann, Julie A. Peterson, Greg Kruger, Lance J. Meinke

Department of Entomology: Faculty Publications

The western corn rootworm (Diabrotica virgifera virgifera LeConte) (WCR) is a major insect pest of corn (Zea mays L.) in the United States (US) and is highly adaptable to multiple management tactics. A low level of WCR field-evolved resistance to pyrethroid insecticides has been confirmed in the US western Corn Belt by laboratory dose-response bioassays. Further investigation has identified detoxification enzymes as a potential part of the WCR resistance mechanism, which could affect the performance of insecticides that are structurally related to pyrethroids, such as organophosphates. Thus, the responses of pyrethroid-resistant and -susceptible WCR populations to the commonly used pyrethroid …

Bacterially Expressed Dsrna Causes Gene Silencing In Eab, Lynne Rieske-Kinney

Entomology Research Data

RNA interference (RNAi) is a naturally occurring, biological process in which RNA molecules inhibit gene expression or translation by neutralizing target mRNA molecules. Recent advances in our understanding of the RNAi mechanism have allowed its development as an emerging tool to protect against insect pests. The major challenge for efficient pest management using RNAi as a molecular bio-pesticide in the field is development of convenient and efficient methods for production, and practical delivery of stable dsRNAs to the target insect. Our goal is to assess the potential for deploying bacterially produced RNAi as a bio-pesticide against an invasive forest pest, …