Article by Jack Bacheler
Plant bug adult. Image LSU, anonymous.
In addition to stink bugs, plant bugs appear to be on the high side in some eastern county cotton fields, with one report of 50% dirty blooms in Chowan County. Although we do not recommend treating on the basis of dirty blooms, dirty bloom levels above approximately 10% should be followed up with direct assessments for live adult and immature plant bugs, preferably with a black ground cloth. Plant bug can also damage small bolls. The exterior damage pictured below resulted from plants bugs being confined to small bolls in a small mesh cage. The internal and external damage symptoms cannot be distinguished from that of stink bugs. Insecticides that are active against stink bugs generally provide good control of plant bug in the Southeast.
Plant bug damage to bolls. Image by Jack Bacheler.
A sample of hard-to-control cotton aphids from Gates County was submitted to Jeff Gore at Mississippi State University by Ames Herbert of Va Tech early lasy week. The population showed a tolerance/resistance level in the range of 20-fold (compared to a chloronicotinoid-susceptible population), thus helping to explain at least some of the recent control issues that had been reported in NC following the use of this chemical class. If poor control is noted following the use of Admire Pro or Centric and a retreatment is needed, an aphid-active material in a different chemical class (such as Carbine) is recommended. Fortunately, most cotton aphid populations are presently being controlled by the naturally-occurring fungal pathogen Neozygites fresenii.