Verde Plant Bug Association with Boll Damage Including Cotton Boll Rot and Potential In-Season Indicators of Damage

A replicated grower field survey was done to capture a range of boll-feeding sucking bug species, in-season boll feeding responses, and damage including cotton boll rot, in South Texas during 2010 and 2011. Cotton boll rot was found on up to 25% of the open bolls inspected in coastal fields, and verde plant bug was the dominant boll-feeding sucking bug species collected (>98% of boll-feeding sucking bugs during peak to late bloom). Field cage trials that isolated verde plant bug feeding activity confirmed that it introduces boll rot-causing organisms. A stepwise regression using 4 independent variables (1. verde plant bug per plant [using a beat bucket or sweep net], 2. proportion of green bolls with signs of external feeding, 3. proportion of green bolls with signs of internal feeding, and 4. proportion of green bolls with signs of boll rot) identified a one independent variable model as the best indicator of at-harvest boll damage. Verde plant bug per plant using a beat bucket was the selected model. Input of other variables did not increase the informative value of the regression using beat bucket sampling for verde plant bugs as an indicator of at-harvest damage. But because verde plant bug presence is an early step in the sequence of events leading to boll damage, cracking a few bolls to detect internal feeding may be useful to supplement the efficient beat bucket sampling method. We are working on using independent data sets to validate this approach.