Browsing by Author "Jacobson, Alana L."

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    Sampling Optimization and Crop Interface Effects on Lygus lineolaris Populations in Southeastern USA Cotton
    Dorman, Seth J.; Taylor, Sally V.; Malone, Sean; Roberts, Phillip M.; Greene, Jeremy K.; Reisig, Dominic D.; Smith, Ronald H.; Jacobson, Alana L.; Reay-Jones, Francis P. F.; Paula-Moraes, Silvana; Huseth, Anders S. (MDPI, 2022-01-13)
    Tarnished plant bug, Lygus lineolaris (Hemiptera: Miridae), is an economically damaging pest in cotton production systems across the southern United States. We systematically scouted 120 commercial cotton fields across five southeastern states during susceptible growth stages in 2019 and 2020 to investigate sampling optimization and the effect of interface crop and landscape composition on L. lineolaris abundance. Variance component analysis determined field and within-field spatial scales, compared with agricultural district and state, accounted for more variation in L. lineolaris density using sweep net and drop cloth sampling. This result highlights the importance of field-level scouting efforts. Using within-field samples, a fixed-precision sampling plan determined 8 and 23 sampling units were needed to determine L. lineolaris population estimates with 0.25 precision for sweep net (100 sweeps per unit) and drop cloth (1.5 row-m per unit) sampling, respectively. A spatial Bayesian hierarchical model was developed to determine local landscape (<0.5 km from field edges) effects on L. lineolaris in cotton. The proportion of agricultural area and double-crop wheat and soybeans were positively associated with L. lineolaris density, and fields with more contiguous cotton areas negatively predicted L. lineolaris populations. These results will improve L. lineolaris monitoring programs and treatment management decisions in southeastern USA cotton.
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    The Spatiotemporal Distribution, Abundance, and Seasonal Dynamics of Cotton-Infesting Aphids in the Southern U.S.
    Mahas, John W.; Mahas, Jessica B.; Ray, Charles; Kesheimer, Adam; Steury, Todd D.; Conzemius, Sophia R.; Crow, Whitney; Gore, Jeffrey; Greene, Jeremy K.; Kennedy, George G.; Kerns, David; Malone, Sean; Paula-Moraes, Silvana; Roberts, Phillip; Stewart, Scott D.; Taylor, Sally; Toews, Michael; Jacobson, Alana L. (MDPI, 2023-07-15)
    Cotton leafroll dwarf virus (CLRDV) is an emerging aphid-borne pathogen infecting cotton, Gossypium hirsutum L., in the southern United States (U.S.). The cotton aphid, Aphis gossypii Glover, infests cotton annually and is the only known vector to transmit CLRDV to cotton. Seven other species have been reported to feed on, but not often infest, cotton: Protaphis middletonii Thomas, Aphis craccivora Koch, Aphis fabae Scopoli, Macrosiphum euphorbiae Thomas, Myzus persicae Sulzer, Rhopalosiphum rufiabdominale Sasaki, and Smynthurodes betae Westwood. These seven have not been studied in cotton, but due to their potential epidemiological importance, an understanding of the intra- and inter-annual variations of these species is needed. In 2020 and 2021, aphids were monitored from North Carolina to Texas using pan traps around cotton fields. All of the species known to infest cotton, excluding A. fabae, were detected in this study. Protaphis middletonii and A. gossypii were the most abundant species identified. The five other species of aphids captured were consistently low throughout the study and, with the exception of R. rufiabdominale, were not detected at all locations. The abundance, distribution, and seasonal dynamics of cotton-infesting aphids across the southern U.S. are discussed.