Factors affecting tarnished plant bug spatial dispersion patterns and feeding injury associated in mid-south cotton - Implications for zone management

Abundance and spatial distribution of tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae) was monitored in a multifactor cotton research field trial in northeast Arkansas over several production seasons. Agronomic factors evaluated included different cotton seeding rates, tillage, winter cover crop species and termination timing practices, and within-field, soil texture variability. Results from plant and pest monitoring indicated highest Lygus abundance and feeding injury were associated with plants positioned nearest the field border and with high plant stand densities. Cover crop management and tillage were not significant factors. Cotton lint yields following Lygus feeding injury varied across soil texture classes, and crop response was interpreted as differential tolerance and compensation capacity of plants to feeding injury.
These results demonstrate potential opportunities for building a zone management approach for Lygus. When there are pest-favorable, field borders, site-specific border sprays rather than broadcast sprays may be economically appropriate. Seeding rate prescriptions that result in higher plant population density in those field border management zones could provide a trap crop effect. Protective sprays in late season may be eliminated in field areas where early maturing plants have reached the final stage of crop susceptibility compared to areas with delayed maturity. Information from plant and pest monitoring, yield maps, soil EC maps, and aerial imagery are all important tools for setting zones, but the most important input is experience of the producer and crop advisors to validate the crop management worthiness of establishing the zone.