Search Results (4)

The cotton fleahopper (Pseudatomoscelis seriatus (Reuter)) is an early-season hemipteran plant bug pest of cotton. In transgenic cotton cultivars, Bt event Mpp51Aa2 (Cry51Aa2) affects some other plant bug species (Hemiptera: Miridae) (we henceforth use the common terminology, stating that these cultivars have the ThryvOn trait). Field experiments were conducted in Corpus Christi, Texas, USA, to evaluate the responses of four cotton cultivars with and without the ThryvOn trait to cotton fleahopper infestations, comparing them with early-season foliar insecticide applications of flupyradifurone. Naturally occurring cotton fleahopper populations rose to the economic threshold midway through the first four weeks of squaring, when cotton plants are most sensitive to feeding injury, in 2024 and later in the same period in 2025. Flupyradifurone application significantly reduced adult and nymph abundance, resulting in reduced square abscission (2025) and yield protection that was consistent across cultivars in 2024 but more variable in 2025. Cultivars expressing the ThryvOn trait exhibited modest and variable reductions in adult cotton fleahopper abundance (~10–30%), occasionally benefiting from reduced square abscission but not protected yield. The open boll ratio, used to assess maturity delay, was not affected by cultivar or cotton fleahopper pressure. These results indicate that ThryvOn cultivars may provide limited supplemental benefits but do not replace or enhance the effectiveness of flupyradifurone for cotton fleahopper management. Full article

Boll abscission in cotton (Gossypium spp.) is a key factor that limits yield; however, the molecular mechanisms underlying this process remain poorly understood. In this study, boll abscission characteristics were uncovered in four cotton varieties that exhibited extreme differences in boll abscission rates via tissue sectioning. Transcriptome analysis was performed on the four cotton varieties. Using weighted gene co-expression network analysis (WGCNA) of the transcriptome data, we identified a stearoyl-(acyl-carrier-protein) desaturase (SACPD) as a potential key regulator of boll abscission. We also performed evolutionary analyses on the SACPD gene family across five cotton species and identified 63 members that were classified into four evolutionary clades, with duplication-polyploidization events being a major driver of gene expansion. Tissue-specific expression profiling revealed that Gossypium hirsutum GhSACPD19 is highly expressed in the abscission zone. Our findings suggest a role of GhSACPD19 in regulating boll abscission, likely through metabolism of jasmonate, a well-known positive regulator of abscission. Our work offers new insights into the regulation of organ abscission at cellular and molecular levels and presents a valuable resource for cotton yield improvement. Full article

The leaffooted bug, Leptoglossus phyllopus (L.) (Hemiptera: Coreidae), probes and feeds on tissues of many plant species, including developing cotton bolls, causing seed damage and abscission. Insecticides are the primary tool for managing leaffooted bugs, but concerns about resistance and environmental harm highlight the need for alternative management strategies. One promising approach is using semiochemicals, such as plant- and insect-produced volatile organic compounds (VOCs), to trap or repel pests. Insect herbivores often use plant-produced VOCs to select suitable host plants for feeding and oviposition. Field observations of abundant adult leaffooted bugs on cotton bolls suggest that bugs aggregate at feeding sites. The goal of this study was to characterize VOCs from developing cotton bolls with and without leaffooted bug herbivory and evaluate how these VOCs affect adult bug foraging behavior. A portable dynamic headspace sampling method was used to collect VOCs from developing cotton bolls in the field, and VOC samples were analyzed using gas chromatography–mass spectrometry. Leaffooted bug herbivory induced volatile emissions from cotton bolls, with significant increases in the emissions of six compounds (benzaldehyde, α-pinene, β-pinene, β-myrcene, p-xylene, and (E)-β-caryophyllene). Dual-choice olfactometer assays revealed that adult leaffooted bugs were attracted to VOCs from damaged cotton bolls, as well as being attracted to synthetic benzaldehyde or α-pinene individually. In contrast, leaffooted bugs were repelled by the combination of synthetic benzaldehyde and α-pinene. These findings suggest that VOCs from cotton bolls are attractive to leaffooted bugs and could contribute to the development of attractive lures for integrated pest management. Full article

Soil waterlogging is one of the most serious abiotic stresses on plant growth and crop productivity. In this study, two potassium application levels (0 and 150 kg K₂O hm⁻²) with three types of soil waterlogging treatments (0 d, 3 d and 6 d) were established during cotton flowering and boll-forming stages. The results showed that soil waterlogging markedly reduced RWC (relative water content), gas exchange parameters and cotton biomass. However, potassium application considerably improved the aforementioned parameters. Specifically, 3 d soil waterlogging with potassium increased Pn (net photosynthetic rate), Gs (stomatal conductance), Ci (intercellular CO₂ concentration) and Tr (transpiration rate) by 4.55%, 27.27%, 5.74% and 3.82%, respectively, compared with 3 d soil waterlogging under no potassium, while the abscission rate reduced by 2.96%. Additionally, the number of bolls and fruit nodes under 6 d soil waterlogging with potassium increased by 16.17% and 4.38%, compared with 6 d soil waterlogging under no potassium. Therefore, it was concluded that regardless of 3 d or 6 d soil waterlogging, potassium application alleviated the negative effects of waterlogging by regulating the plant water status, photosynthetic capacity and plant growth in cotton. These results are expected to provide theoretical references and practical applications for cotton production to mitigate the damage of soil waterlogging. Full article