Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/6/2019
Publication Date: N/A
Interpretive Summary: Cotton is a worldwide commodity and is attacked by several seasonal insect pest species. Some pest species, such as stink bugs, use needle-like mouthparts to attack and penetrate the developing cotton fruit (or boll) to introduce plant pathogens. These pest species occur throughout the cotton production season, however, it was unknown at which age the bolls were most susceptible to penetration by pest species with needle-like mouthparts. The objective of this study was to compare known penetration potential of seasonal pests to determine when boll walls of several cotton species were susceptible to breaching by these pests. One of the two pest species occurring during the early-season could only penetrate walls of bolls that were less than 7 days old; the other early-season pest could not penetrate the boll wall at all. Eight stink bug species were evaluated and all species could penetrate the wall of 1-d-old newly formed bolls. Further, virtually all of the stink bug species can penetrate the boll wall even after the wall has achieved maximum thickness at 14 d of age. Typical management tactics include monitoring for stink bugs late in the production season. However, these results indicate that stink bugs can breach the wall as soon as the boll is available and producers should re-consider management tactics to detect these stink bug species earlier in the production season. Earlier detection of stink bugs could potentially minimize yield losses and prevent the introduction of pathogens by the insects.
Technical Abstract: Cotton (Gossypium hirsutum L. [Malvales: Malvaceae]) is a high value cash crop that is usually plagued by various hemipteran insect pests, including lygus bugs (mirids) and stink bugs (pentatomids). Stink bugs can transmit pathogens that cause seed and boll rot of cotton, and lygus bugs can also vector pathogens. However, the temporal susceptibility to breaching of the carpel wall by stink bugs and related species was unknown. Our objective was to compare known stylet penetration estimates of mirids [Lygus lineoloaris Palisot de Beauvois; Pseudatomoscelis seriatus Reuter] and pentatomids [Chinavia hilaris Say, Euschistus obscurus (Palisot), Euschistus servus (Say), E. tristigmus (Say), E. quadrator, Nezara viridula (L.), Oebalus pugnax (F.), Piezodorus guildinii Westwood, and Thyanta custator accerra McAtee] against observed minimum boll wall thickness in entries of G. arboreum, G. barbadense, G. herbaceum, and G. hirsutum to determine the time at which bolls initially become susceptible to stylet penetration. Pseudatomoscelis seriatus cannot breach the boll wall. Lygus lineolaris can breach the wall of bolls at = 7 d after flower in G. herbaceum and in select entries of G. hirsutum. All of the pentatomid species can breach the internal carpel wall of bolls at 1 d after flower and virtually all of the species can continue to breach the boll wall throughout the entire production season regardless of boll age and wall thickness. Monitoring efforts for stink bugs may need to be implemented at boll set to mitigate introduction of pathogens and yield losses given season-long susceptibility of bolls to stink bugs.