Browsing by Author "Bekelja, Kyle"
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- 2021 Virtual Eastern Shore Agricultural Conference and Trade ShowPittman, Theresa; Deitch, Ursula T.; Reiter, Mark S.; Singh, Vijay; Mason, John; Duerksen, Keren; Haymaker, Joseph; Doughty, Helene; Holshouser, David Lee, 1963-; Langston, David B.; Flessner, Michael; Rideout, Steven L.; Thomason, Wade E.; McCullough, Chris T.; Sutton, Kemper L.; Bekelja, Kyle; Kuhar, Thomas P.; Richardson, Bruce; Harper, Robert; Richardson, Brett; Shockley, Bill (Virginia Cooperative Extension, 2021-03-12)Join us for the 2021 virtual Eastern Shore Agricultural Conference and Trade Show! Hear updates and continuing education presentations that are pertinent to Eastern Shore of Virginia growers.
- Effect of Insecticides on the Control of Mexican Bean Beetle and Stink Bugs in Snap Beans in Virginia, 2022Walls, Courtney; Bekelja, Kyle; McIntyre, Kelly; Kuhar, Thomas P. (Oxford University Press, 2023)
- Effects of Selected Insecticides Against Alfalfa Weevil Infesting Alfalfa, 2022Bekelja, Kyle; McIntyre, Kelly; Kuhar, Thomas P. (Entomological Society of America, 2023)
- Effects of Selected Insecticides Against Insect Pests Infesting Alfalfa, 2022Bekelja, Kyle; McIntyre, Kelly; Kuhar, Thomas P. (Entomological Society of America, 2023)
- Effects of Selected Insecticides in Rotation Against Corn Earworm Infesting Sweet Corn, 2022Bekelja, Kyle; McIntyre, Kelly; Kuhar, Thomas P. (Entomological Society of America, 2023)
- Effects of Selected Organic Insecticides Against Mexican Bean Beetle and Stink Bugs Infesting Snap Beans, 2022Bekelja, Kyle; McIntyre, Kelly; Kuhar, Thomas P. (Entomological Society of America, 2023)
- Effects of Selected Organic Insecticides in Rotation Against Corn Earworm Infesting Sweet Corn, 2022Bekelja, Kyle; McIntyre, Kelly; Kuhar, Thomas P. (Entomological Society of America, 2023-01)
- Efficacy of Selected Insecticides Against Flea Beetle and Harlequin Bug in Cabbage in Virginia, 2022Sydnor, Taylore; McIntyre, Kelly; Bekelja, Kyle; Kuhar, Thomas P. (Entomological Society of America, 2023)
- Establishment and Distribution of Laricobius spp. (Coleoptera: Derodontidae), a Predator of Hemlock Woolly Adelgid, Within the Urban Environment in Two Localities in Southwest VirginiaFoley, Jeremiah R.; McAvoy, Thomas J.; Dorman, Seth; Bekelja, Kyle; Kring, Timothy J.; Salom, Scott M. (Oxford University Press, 2019-09-30)Hemlock woolly adelgid (HWA), Adelges tsugae Annand, is a highly destructive non-native pest lethal to eastern hemlock, Tsuga canadensis (L.) Carrière, and Carolina hemlock, T. caroliniana Engelmann. Fifty years following the first observation of HWA in eastern North America, a predatory beetle, Laricobius nigrinus Fender, was evaluated, approved, and released as a biological control agent. Efforts were made to mass rear L. nigrinus with the goal of redistributing the beetles on public lands, typically in forest ecosystems, as a secondary option to silvicultural and chemical controls. The majority of L. nigrinus releases has occurred on public lands. Herein, we report the observation of L. nigrinus within the urban environment outside of known release locations. Two towns, Blacksburg and Radford, were divided into 0.40 km2 grids. A total of 27 and 19 grids were randomly selected from each town, respectively. Hemlocks were present in 44 and 42% of the grids surveyed in Blacksburg and Radford, respectively. In Blacksburg and Radford, 86 and 100% of the grids with hemlocks were infested with HWA, and of those infested hemlocks, Laricobius spp. was present in 100 and 75% of grids, respectively. A total of 154 Laricobius spp. (98% L. nigrinus and 2% Laricobius rubidus) adults were collected between each town. While it is unclear the level of control L. nigrinus has on reducing HWA's impact, the establishment of this biological control agent in the urban environment is an additional level of predation, that would otherwise not be present, for homeowners with HWA-infested trees.
- A Novel Insecticide, Isocycloseram, Shows Promise as an Alternative to Chlorpyrifos Against a Direct Pest of PeanutBekelja, Kyle; Malone, Sean; Mascarenhas, Victor; Taylor, Sally V. (2024-01)Larvae of the southern corn rootworm (SCR) Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae) are primary pests of peanut in the Virginia-Carolina region of the United States, and are relatively sporadic pests in southern states such as Georgia, Alabama, and Florida. Peanuts have strict quality standards which, when they are not met, crop value is diminished by more than 65%. Management of direct pests like SCR is therefore crucial to maintaining the economic viability of the crop. The soil-dwelling nature of SCR larvae complicates management due to difficulties associated with monitoring and predicting infestations. Non-chemical management options are limited in this system; preventative insecticide applications are the most reliable management strategy for at-risk fields. Chlorpyrifos was the standard product for larval SCR management in peanut until its registration was revoked in 2022, leaving no effective chemical management option for larvae. We tested a novel insecticide, isocycloseram, for its ability to reduce pod scarring, pod penetration, and non-SCR pod damage in field studies conducted in Suffolk, Virginia in 2020 – 2022. Overall injury was low in 2020 and 2022, and in 2022 there was not a significant effect of treatment. In 2021, two simulated chemigation applications of isocycloseram in July significantly reduced pod scarring and overall pod injury relative to chlorpyrifos and the untreated control. Our results suggest that isocycloseram may become an effective option for managing SCR in peanut, although more work is needed to understand the mechanisms by which it is effective as a soil-applied insecticide.
- Removing Neonicotinoid Seed Treatments Has Negligible Effects on Refuge Function and Crop Protection in Transgenic Maize Targeting Western Corn Rootworm (Coleoptera: Chrysomelidae)Bekelja, Kyle; Miller, Kathleen; Kuhar, Thomas P.; Krupke, Christian; Taylor, Sally V. (Entomological Society of America, 2023-01)Nearly all maize seed sold in the United States (US) includes a neonicotinoid seed treatment (NST), meant to protect seedlings against early-season insect pests. For key pests, including western corn rootworm (Diabrotica virgifera virgifera LeConte) (D.v.v), insecticidal proteins derived from Bacillus thuringiensis (Bt) are expressed in plant tissues as alternatives to soil-applied insecticides. Insect resistance management (IRM) plans use non-Bt “refuges” to encourage survival of Bt-susceptible D.v.v., which maintains susceptible alleles in the population. In non-cotton producing regions, IRM guidelines require a minimum 5% blended refuge for maize expressing more than one trait targeting D.v.v. Prior work has shown that 5% blends yield insufficient proportions of refuge beetles to contribute reliably to IRM. Whether NSTs interfere with survivorship of refuge beetles is unknown. Our objective was to determine whether NSTs affect proportions of refuge beetles, and secondarily, to determine whether NSTs provide agronomic advantages over Bt seed alone. To reveal host plant type (i.e., Bt or refuge), we used stable isotopes (15N) to mark refuge plants in plots with 5% seed blends. To assess refuge performance between treatments, we compared proportions of beetles from respective natal hosts. In all site-years, NSTs showed inconsistent, often negligible, effects on proportions of refuge beetles. Treatment comparisons showed inconsistent agronomic benefits of NSTs when combined with Bt traits. Our results demonstrate that NSTs have a negligible impact on refuge performance and reinforces the assertion 5% blends are serving little benefit for IRM. Plant stand and yield were not improved by NSTs.
- A Study of Neonicotinoid Seed Treatments in Bt Maize: Insect Resistance Management, Efficacy, and Environmental FateBekelja, Kyle (Virginia Tech, 2022-06-10)Roughly 79-100% of maize in the United States (US) is treated with a neonicotinoid seed treatment (NST), and transgenic (GMO) maize, Zea mays L. (Poaceae), that produces insecticidal toxins by way of genes derived from Bacillus thuringiensis (Bt), occupies more than 75% of maize acreage. Among a variety of secondary pests targeted by NSTs, the primary soil-dwelling pest targeted by Bt maize is the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae). Transgenic Bt technology has dramatically reduced insecticide use for WCR, and insect resistance poses the greatest threat to its utility. To delay resistance to Bt traits, in 2010 the US Environmental Protection Agency (EPA) approved a "refuge-in-a-bag" (RIB) insect resistance management (IRM) strategy, where 5% of seeds do not express Bt toxins (i.e., "refuge" maize). The RIB strategy is intended to preserve Bt trait effectiveness if mating between 'resistant' insects from Bt plants and 'susceptible' insects from refuge plants occurs at a high enough frequency. Investigations into the effectiveness of RIB for WCR have shown that beetles emerged from Bt plants tend to vastly outnumber beetles emerged from refuge plants, which contributes to low rates of mixed mating. Large proportions of Bt beetles is one of several factors that contributes to resistance development, and resistance to all currently-available WCR-Bt traits has been documented. I conducted field experiments in two regions (Indiana and Virginia) comparing refuge beetle proportions in NST-treated (NST+) and NST-untreated (NST-) 5% RIB maize, to determine whether NSTs may be limiting refuge beetle emergence. To assess advantages of combining use of Bt and NSTs, I compared stand, root injury rating, and yield between NST+, NST-, Bt and non-Bt maize in both states. I also measured neonicotinoid residues in soil, water, and stream sediment within and surrounding fields of maize, to study the off-site movement and soil residence time of these compounds. I found that 5% seed blends did not produce large populations of refuge beetles in any site-year, and that NSTs showed inconsistent effects on refuge beetle populations. Treatment comparisons showed inconsistent benefits of NSTs when combined with Bt traits. I detected neonicotinoid residues in soil matrices throughout the growing season (range: 0 – 417.42 ppb), including prior to planting, suggesting year-round presence of these compounds. My results suggest that, while the effects of NSTs on Bt IRM may be inconsistent, the benefits of universally applying NSTs to Bt maize for soil pests may not be worth the ecological costs of doing so in all cases.
- Testing Novel Seed Treatments and Soil-Applied Insecticides Against Wireworm in Corn, 2023Bekelja, Kyle; Malone, Sean (Oxford University Press, 2024-01)
- Western Corn RootwormBekelja, Kyle; Kuhar, Thomas P.; Taylor, Sally V. (Virginia Cooperative Extension, 2019-02-15)Describes the western corn rootworm, its life cycle, and damage to corn plants.