Greenbug [Schizaphis graminum (Rondani)] is a serious insect pest that not only damages cereal crops, but also transmits several destructive viruses. The emergence of new greenbug biotypes in the field makes it urgent to identify novel greenbug resistance genes in wheat. CWI 76364 (PI 703397), a synthetic hexaploid wheat (SHW) line, exhibits greenbug resistance.
View Article and Find Full Text PDFThe number, timing, and fitness of colonizing parasitoids in fields of ephemeral crops often depend on factors external to the fields. We investigated cereal aphid parasitism in 23 winter wheat fields using sentinel plants infested with bird cherry-oat aphids, Rhopalosiphum padi (L.) (Hemiptera: Aphididae), and we investigated the effect of parasitoids on cereal aphid population growth using exclusion and parasitoid-accessible cages infested with bird cherry-oat aphids.
View Article and Find Full Text PDFWe propose that a growing research base considering pest management as an ecosystem service can be leveraged to expand areawide pest management (AWPM) to an agroecological-oriented framework when addressing pest arthropods in cropping systems. This AWPM framework centers on the innate capacity of the agroecosystem to suppress pests and is supported with strategic insertion of AWPM tactics. Recent studies on agroecological pest management are valuable to identify AWPM candidates.
View Article and Find Full Text PDFThe sorghum ( [L.]) agroecosystem of North America provided an opportunity to evaluate agroecosystem response to an invading insect herbivore, (Theobald) (sorghum aphid) (previously published as Zehntner) (Hemiptera: Aphididae) onto a widely planted crop that experiences a range of agro-landscape and weather conditions. Initial sorghum risk assessments after 's invasion in the mid-2010s provided forecasts of range expansion and annual migration, which were based on aphid life history, extent of sorghum cultivation and susceptibility to , and weather (aphid-plant-weather [APW] risk scenario).
View Article and Find Full Text PDFThe sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), is an invasive sorghum pest that has threatened over 90% of North American sorghum production. Resident parasitoids, coccinellids, syrphids, and lacewings prey on this aphid. Our objective was to compare and estimate parasitoid and predator suppression of sugarcane aphids placed on resistant and susceptible hybrids in a field setting using natural enemy exclusion cages.
View Article and Find Full Text PDFObjective: To characterize disordered eating behaviors, eating disorder (ED) risk and diagnosis, and treatment seeking behaviors in active-duty military personnel/veterans compared with civilians.
Method: Self-selecting participants (n = 113,388; 1744 were military personnel/veterans) 18+ years old completed the National Eating Disorders Association's online screen. Engagement in and frequencies of disordered eating behaviors were compared across military/veteran and civilian groups and were stratified by gender.
Sugarcane aphid Melanaphis sacchari Zehntner is a significant economic pest of grain sorghum in the United States. Effective monitoring and early detection are cornerstones for managing invasive pests. The recently developed binomial sequential sampling plan estimates sugarcane aphid economic thresholds (ETs) based on classification whether a 2-leaf sample unit has ≤ or ≥ 50 M.
View Article and Find Full Text PDFThe sugarcane aphid (Melanaphis sacchari Zehntner) is a significant economic pest of grain sorghum (Sorghum bicolor (L.) Moench) in the Southern United States. Current nominal and research-based economic thresholds are based on estimates of mean aphids per leaf.
View Article and Find Full Text PDFWinter canola Brassica napus L. (Brassicales: Brassicaceae) was introduced to U.S.
View Article and Find Full Text PDFWinter wheat is Oklahoma's most widely grown crop, and is planted during September and October, grows from fall through spring, and is harvested in June. Winter wheat fields are typically interspersed in a mosaic of habitats in other uses, and we hypothesized that the spatial and temporal composition and configuration of landscape elements, which contribute to agroecosystem diversity also influence biological control of common aphid pests. The parasitoid Lysiphlebus testaceipes (Cresson; Hymenoptera: Aphidiinae) is highly effective at reducing aphid populations in wheat in Oklahoma, and though a great deal is known about the biology and ecology of L.
View Article and Find Full Text PDFOf the many ways biological control can be incorporated into Integrated Pest Management (IPM) programs, natural enemy thresholds are arguably most easily adopted by stakeholders. Integration of natural enemy thresholds into IPM programs requires ecological and cost/benefit crop production data, threshold model validation, and an understanding of the socioeconomic factors that influence stakeholder decisions about biological control. These thresholds are more likely to be utilized by stakeholders when integrated into dynamic web-based IPM decision support systems that summarize pest management data and push site-specific biological control management recommendations to decision-makers.
View Article and Find Full Text PDFIn 2013, the sugarcane aphid, (Zehntner) (Hemiptera: Aphididae), a new invasive pest of sorghum species in North America, was confirmed on sorghum in 4 states and 38 counties in the United States. In 2015, the aphid was reported on sorghum in 17 states and over 400 counties as well as all sorghum-producing regions in Mexico. Ability to overwinter on living annual and perennial hosts in southern sorghum-producing areas and wind-aided movement of alate aphids appear to be the main factors in its impressive geographic spread in North America.
View Article and Find Full Text PDFEight QTL for coleoptile length were identified in a genome-wide association study on a set of 893 wheat accessions, four of which are novel loci. Wheat cultivars with long coleoptiles are preferred in wheat-growing regions where deep planting is practiced. However, the wide use of gibberellic acid (GA)-insensitive dwarfing genes, Rht-B1b and Rht-D1b, makes it challenging to breed dwarf wheat cultivars with long coleoptiles.
View Article and Find Full Text PDFRemote sensing describes the characterization of the status of objects and/or the classification of their identity based on a combination of spectral features extracted from reflectance or transmission profiles of radiometric energy. Remote sensing can be benchtop based, and therefore acquired at a high spatial resolution, or airborne at lower spatial resolution to cover large areas. Despite important challenges, airborne remote sensing technologies will undoubtedly be of major importance in optimized management of agricultural systems in the twenty-first century.
View Article and Find Full Text PDFCreating conditions that enhance the abundance of resident populations of natural enemies in agroecosystems is considered critical to the efficiency of biological control of insect pests. We conducted a study to determine the potential of relay-intercropping for enhancing the abundance of aphidophagous lady beetles in sorghum. A relay-intercropping system consisting of alfalfa, winter wheat, and cotton as intercrops and sorghum as a main crop was compared with sorghum monoculture plots at two study sites in OK from 2003 to 2006.
View Article and Find Full Text PDFSupercooling points (SCPs) were measured for various life stages of male and female Lysiphlebus testaceipes (Cresson) parasitoids, along with mummies and its aphid host, Schizaphis graminum (Rondani). Some parasitoids were acclimated (4 h at 10 degrees C before cooling down to the SCP) to determine whether this could significantly lower the SCP. Acclimation did not improve SCPs for L.
View Article and Find Full Text PDFWe studied life history responses of larvae of three coccinellid species, Coleomegilla maculata (DeGeer), Hippodamia convergens Guerin-Meneville, and Harmonia axyridis (Pallas), when deprived of food for different periods of time during the fourth stadium. The coccinellid species did not differ in starvation resistance when larvae were starved throughout the stadium; however, for larvae fed only on day 1 of the stadium, H. convergens had the highest starvation resistance, followed by H.
View Article and Find Full Text PDFAlthough spectral remote sensing techniques have been used to study many ecological variables and biotic and abiotic stresses to agricultural crops over decades, the potential use of these techniques for greenbug, Schizaphis graminum (Rondani) (Hemiptera: Aphididae) infestations and damage to wheat, Triticum aestivum L., under field conditions is unknown. Hence, this research was conducted to investigate: 1) the applicability and feasibility of using a portable narrow-banded (hyperspectral) remote sensing instrument to identify and discern differences in spectral reflection patterns (spectral signatures) of winter wheat canopies with and without greenbug damage; and 2) the relationship between miscellaneous spectral vegetation indices and greenbug density in wheat canopies growing in two fields and under greenhouse conditions.
View Article and Find Full Text PDFFrom 1998 to 2001, the relationship between the proportion of tillers with >0 mummified aphids (Ptm) and the proportion of cereal aphids parasitized (Pp) was estimated on 57 occasions in fields of hard red winter wheat located in central and western Oklahoma. Both original (57 fields) and validation data (34 fields; 2001-2002) revealed weak relationships between Ptm and Pp, however, when Ptm > 0.1, Pp always exceeded the recommended parasitism natural enemy threshold of 0.
View Article and Find Full Text PDFSeven native coccinellid species inhabited alfalfa, corn, and small grain fields in eastern South Dakota prior to invasion and establishment of Coccinella septempunctata L. Six species occurred in all crops, however, Adalia bipunctata (L.) occurred only in corn.
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