Browsing by Author "Malone, Sean M."
Now showing 1 - 17 of 17
Results Per Page
Sort Options
- Aphids in Virginia Small Grains: Life Cycles, Damage and ControlMalone, Sean M.; Taylor, Sally V.; Day, Eric R. (Virginia Cooperative Extension, 2019-03-20)Describes life cycle of four species of aphid and damage on small grain crops in Virginia. Discusses prediction of aphid population outbreaks and methods of sampling plants for aphids. Also discusses aphid predators and parasites.
- Assessment of Soybean Leaf Area for Redefining Management Strategies for Leaf-Feeding InsectsMalone, Sean M. (Virginia Tech, 2001-08-31)Commercially available leaf area index (LAI) meters are tools that can be used in making insect management decisions. However, proper technique must be determined for LAI estimation, and accuracy must be validated for the meters. Full-season soybean require LAI values of at least 3.5 to 4.0 by early to mid-reproductive developmental stages to achieve maximum yield potential, but the relationship between double-crop soybean LAI and yield is unknown. This research (1) evaluated minimum plot size requirements for mechanically defoliated soybean experiments using the LAI-2000 Plant Canopy Analyzer, (2) compared LAI estimates among LAI-2000 detector types which respond to different wavelengths of light, (3) compared LAI-2000 estimates with directly determined LAI values for 0, 33, 66, and 100% mechanical defoliation levels, (4) used linear and non-linear models to describe the response of full-season and double-crop soybean yields to reductions in LAI through mechanical defoliation, and (5) evaluated the response of double-crop soybean yields to reductions in LAI through insect defoliation. The minimum plot size for obtaining accurate LAI estimates of defoliated canopies in soybean with 91 cm row centers is four rows by 2 m, with an additional 1 m at the ends of the two middle rows also defoliated. The wide-blue detector, which is found in newer LAI-2000 units and responds to wavelengths of light from 360 to 460 nm, gave higher LAI estimates than the narrow-blue detector, which responds to light from 400 to 490 nm. The unit with the narrow-blue detector gave estimates equal to directly determined LAI in two of three years for 0, 33, and 66% defoliation levels, while the units with the wide-blue detectors gave estimates higher than directly determined LAI in the two years that they were studied, except for a few accurate 33% defoliation estimates. Therefore, the LAI-2000 usually provides reasonable estimates of LAI. Yield decreased linearly with LAI when LAI values were below 3.5 to 4.0 by developmental stages R4 to R5 in both full-season and double-crop soybean. Usually, there was no relationship between yield and LAI at LAI values greater than 4.0. There was an average yield reduction of 820 ± 262 kg ha⁻¹ for each unit decrease in LAI below the critical 3.5 to 4.0 level; maximum yields ranged from 1909 to 3797 kg ha⁻¹. Insect defoliators did not defoliate double-crop soybean plots to LAI levels less than 4.0, and there was no yield difference between insect-defoliated and control plots. Therefore, double-crop soybean that maintains LAI values above the 3.5 to 4.0 critical level during mid-reproductive developmental stages is capable of tolerating defoliating pest
- Brown Marmorated Stink Bug, Biology and Management in Mid-Atlantic SoybeansAigner, Benjamin L.; Kuhar, Thomas P.; Hogue, Jamie; Malone, Sean M.; Herbert, D. Ames Jr.; Seymore, Ed (Virginia Cooperative Extension, 2015-11-05)Reviews the life cycle and threat of the brown marmorated stink bug, its impact on soybean plants, and management strategies to minimize this impact, and protect soybean crops.
- Contrasting Role of Temperature in Structuring Regional Patterns of Invasive and Native Pestilential Stink BugsVenugopal, P. Dilip; Dively, Galen P.; Herbert, D. Ames Jr.; Malone, Sean M.; Whalen, Joanne; Lamp, William O. (PLOS, 2016-02-29)Objectives Assessment and identification of spatial structures in the distribution and abundance of invasive species is important for unraveling the underlying ecological processes. The invasive agricultural insect pest Halyomorpha halys that causes severe economic losses in the United States is currently expanding both within United States and across Europe. We examined the drivers of H. halys invasion by characterizing the distribution and abundance patterns of H. halys and native stink bugs (Chinavia hilaris and Euschistus servus) across eight different spatial scales. We then quantified the interactive and individual influences of temperature, and measures of resource availability and distance from source populations, and their relevant spatial scales. We used Moran’s Eigenvector Maps based on Gabriel graph framework to quantify spatial relationships among the soybean fields in mid-Atlantic Unites States surveyed for stink bugs. Findings Results from the multi-spatial scale, multivariate analyses showed that temperature and its interaction with resource availability and distance from source populations structures the patterns in H. halys at very broad spatial scale. H. halys abundance decreased with increasing average June temperature and distance from source population. H. halys were not recorded at fields with average June temperature higher than 23.5°C. In parts with suitable climate, high H. halys abundance was positively associated with percentage developed open area and percentage deciduous forests at 250m scale. Broad scale patterns in native stink bugs were positively associated with increasing forest cover and, in contrast to the invasive H. halys, increasing mean July temperature. Our results identify the contrasting role of temperature in structuring regional patterns in H. halys and native stink bugs, while demonstrating its interaction with resource availability and distance from source populations for structuring H. halys patterns. Conclusion These results help predicting the pest potential of H. halys and vulnerability of agricultural systems at various regions, given the climatic conditions, and its interaction with resource availability and distance from source populations. Monitoring and control efforts within parts of the United States and Europe with more suitable climate could focus in areas of peri-urban developments with deciduous forests and other host plants, along with efforts to reduce propagule pressure.
- Field Guide to Stink Bugs of agricultural importance in the United StatesHerbert, D. Ames Jr.; Kamminga, Katherine; Malone, Sean M.; Kuhar, Thomas P.; Day, Eric R.; Greene, Jeremy K.; Bundy, C. Scott; Brown, Lydia; Ellsworth, Peter C. (Virginia Cooperative Extension, 2020)Descriptions of different types of stink bugs and the economic damage they can do to crops
- Field Guide to Stink Bugs of Agricultural Importance in the United StatesHerbert, D. Ames Jr.; Kamminga, Katherine; Malone, Sean M.; Kuhar, Thomas P.; Day, Eric R.; Greene, Jeremy K.; Brown, Lydia; Ellsworth, Peter C. (Virginia Cooperative Extension, 2014-11-17)This field guide provides information on common and less common species of stink bugs in the United States. Text along with pictures helps with identification of eggs, nymphs and adults of both pests and beneficial species of stink bugs.
- Field Guide to Stink Bugs of Agricultural Importance in the Upper Southern Region and Mid-Atlantic StatesKamminga, Katherine; Herbert, D. Ames Jr.; Malone, Sean M.; Kuhar, Thomas P.; Greene, Jeremy K. (Virginia Cooperative Extension, 2009-07-29)This field guide provides information on common and less common species of stink bugs in the region. Text along with pictures helps with identification of eggs, nymphs and adults of both pest and beneficial species of stink bugs.
- Fifty Years of Cereal Leaf Beetle in the U.S.: An Update on Its Biology, Management, and Current ResearchPhilips, Christopher R.; Herbert, D. Ames Jr.; Kuhar, Thomas P.; Reisig, Dominic D.; Thomason, Wade E.; Malone, Sean M. (Entomological Society of America, 2011-10-01)Cereal leaf beetle, Oulema melanopus L., is an introduced insect pest of small grains first recorded in the United States in the early 1960s. Since its introduction from Europe or Asia into Michigan, cereal leaf beetle has rapidly spread and can now be found in most states. Cereal leaf beetle feeds on numerous species of grasses and is considered a major pest of oats, barley, and wheat. Although several studies have investigated cereal leaf beetle biology and population dynamics, numerous gaps remain in understanding the mechanisms that influence its spread and distribution, which makes predicting pest outbreaks difficult. Because of the difficulty in predicting when and where pest outbreaks will occur many growers in the southeast apply insecticides on a calendar basis rather than using a threshold-based integrated pest management approach. Our challenge is to develop new information and procedures that will encourage growers to reevaluate the way they are approaching spring-time insect control in wheat, and consider adoption of the integrated pest management approach. This article is a review of cereal leaf beetle biology, past and present management practices, and current research being conducted.
- Identifying Soybean Fields at Risk to Leaf-Feeding InsectsMalone, Sean M.; Holshouser, David L.; Herbert, D. Ames Jr.; Jones, Brian Paul (Virginia Cooperative Extension, 2018-11-13)Discusses the use of leaf area index for soybean crops in relation to potential crop yield, and damage from insect pests.
- Identifying Soybean Fields at Risk to Leaf-Feeding InsectsMalone, Sean M.; Holshouser, David L.; Herbert, D. Ames Jr.; Jones, Brian Paul (Virginia Cooperative Extension, 2009-05-01)Provides information about assessing the risk of damage to soybean fields.
- The influence of pheromone dispenser release rates, trap height and pheromone dispenser height on captures of leafrollers in Virginia apple orchardsMalone, Sean M. (Virginia Tech, 1996)Gravimetric analysis was used to determine the release rates and longevities of several designs of pheromone dispensers for mating disruption of leafrollers and codling moth, Cydia pomonella (Linneaus). Release rates were described by linear equations for at least four months, but by the end of the season release rates tended to become erratic. Biocontrol’s red-brown codling moth dispenser lasted for up to four months, and one application of the dispenser in early May should control codling moth for the entire season in Virginia apple orchards. Ecogen and Hercon leafroller dispensers lasted for a shorter time than the codling moth dispensers and would require two applications per season to provide the best control of their target pests. In a commercial northern Virginia apple orchard, the effects of pheromone trap height and pheromone dispenser height on captures of the tufted apple bud moth, Platynota idaeusalis (Walker), were studied. Low traps (2.0 m) were more sensitive than high traps (4.5 m) for monitoring tufted apple bud moth. The number of moths caught in 1994 and 1995 in a two-hectare mating disruption plot with pheromone dispensers placed in the upper third of the tree was not significantly different from the number caught in a plot with pheromone dispensers placed at head height. Fruit damage was very high in both pheromone plots in 1994, but by 1995 it appeared that mating disruption was able to reduce fruit damage due to leafroller larvae.
- Mid-Atlantic Guide to the Insect Pests and Beneficials of Corn, Soybean, and Small GrainsHerbert, D. Ames Jr.; Malone, Sean M.; Dively, Galen; Greene, Jeremy K.; Tooker, John; Whalen, Joanne; Youngman, Roger R. (Virginia Cooperative Extension, 2011)This document offers brief descriptions and photos of common insect pests and beneficial insects in corn, soybean and small grain crops in the mid-Atlantic region.
- Mid-Atlantic Guide to the Insect Pests and Beneficials of Corn, Soybean, and Small GrainsHerbert, D. Ames Jr.; Malone, Sean M.; Dively, Galen; Greene, Jeremy K.; Tooker, John; Whalen, Joanne; Youngman, Roger R. (Virginia Cooperative Extension, 2018-11-13)Offers brief descriptions and photos of common insect bests and beneficial insects in corn, soybean, and small grain crops in the mid-Atlantic region.
- Monitoring and Management of Beet Armyworm and Other Rind-feeding Larvae in WatermelonHerbert, D. Ames Jr.; Kuhar, Thomas P.; Malone, Sean M.; Whalen, Joanne (Virginia Cooperative Extension, 2011-04-21)Describes Beet Armyworm and other rind-feeding larvae in watermelon, their damage to crops, and notes methods of control.
- Neonicotinoid seed treatments of soybean provide negligible benefits to US farmersMourtzinis, Spyridon; Krupke, Christian H.; Esker, Paul D.; Varenhorst, Adam; Arneson, Nicholas J.; Bradley, Carl A.; Byrne, Adam M.; Chilvers, Martin, I.; Giesler, Loren J.; Herbert, D. Ames Jr.; Kandel, Yuba R.; Kazula, Maciej J.; Hunt, Catherine; Lindsey, Laura E.; Malone, Sean M.; Mueller, Daren S.; Naeve, Seth; Nafziger, Emerson D.; Reisig, Dominic D.; Ross, William J.; Rossman, Devon R.; Taylor, Sally V.; Conley, Shawn P. (Springer Nature, 2019-09-09)Neonicotinoids are the most widely used insecticides worldwide and are typically deployed as seed treatments (hereafter NST) in many grain and oilseed crops, including soybeans. However, there is a surprising dearth of information regarding NST effectiveness in increasing soybean seed yield, and most published data suggest weak, or inconsistent yield benefit. The US is the key soybean-producing nation worldwide and this work includes soybean yield data from 194 randomized and replicated field studies conducted specifically to evaluate the effect of NSTs on soybean seed yield at sites within 14 states from 2006 through 2017. Here we show that across the principal soybean-growing region of the country, there are negligible and management-specific yield benefits attributed to NSTs. Across the entire region, the maximum observed yield benefits due to fungicide (FST = fungicide seed treatment) + neonicotinoid use (FST+NST) reached 0.13 Mg/ha. Across the entire region, combinations of management practices affected the effectiveness of FST+NST to increase yield but benefits were minimal ranging between 0.01 to 0.22 Mg/ha. Despite widespread use, this practice appears to have little benefit for most of soybean producers; across the entire region, a partial economic analysis further showed inconsistent evidence of a break-even cost of FST or FST+ NST. These results demonstrate that the current widespread prophylactic use of NST in the key soybean-producing areas of the US should be re-evaluated by producers and regulators alike.
- Winter Grain Mite potential pest for small grains and orchardgrassHerbert, D. Ames Jr.; Malone, Sean M. (Virginia Cooperative Extension, 2020)The Winter Grain Mite, it's description, hosts, lifecycle, the type of damage they do, and control methods
- Winter Grain Mite: Potential Pest of Small Grains and OrchardgrassHerbert, D. Ames Jr.; Malone, Sean M. (Virginia Cooperative Extension, 2009)Describes the Winter Grain Mite (Penthaleus major), its life cycle, damage to grain plants and orchardgrass, and discusses methods of control.