Bollworms found in some cotton
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By Dagan Teague/IPM Agent-Floyd & Crosby County—
FLOYD COUNTY – This week in cotton we were finding small bollworms in some non-Bt cotton fields that were above threshold.
Bollworm larvae full-grown are about 1 1⁄2 inches long and vary in color from pale green, pink, or brownish to black, with stripes along the back. They are attracted to and lay eggs in cotton with lush new growth. Moths sometimes deposit eggs on squares, bolls, stems, and lower parts of the plant when cotton plants are stressed and making little new growth, or during periods of high temperature and low humidity.
Moths usually lay single eggs on the tops or undersides of young, tender, leaves on the tops of the plant. However, in Bt cotton, moths frequently lay eggs on blooms, bloom tags, or other tissues deeper in the canopy because these tissues have lower concentrations of Bt protein toxins. Eggs are white to cream color and about the size of a pinhead or smaller. They can be confused with other eggs. Eggs hatch in 3 to 4 days, turning light brown before hatching. Young worms usually feed for a day or two on leaves, leaf buds, and small squares in the plant terminal before moving down the plant to attack larger squares and bolls. Small worms are most vulnerable to insecticides when they are in the upper third of the plant.
There also has been a few cotton Stainers seen around as well, but nothing over threshold to be worried about spraying for. The cotton Stainer is a true bug that has piercing-sucking mouth-parts. This damages developing bolls by puncturing seeds and causing plant sap to stain the lint.
Also, there has been a few fields exhibiting verticillium wilt symptoms this week. While there is little that you can do to help once verticillium symptoms appear. There are measures you can take advantage of in the off-season management that can be made.
Sorghum
There has been activity with aphids this week again. Some of the fields in the area have needed treatment, while other fields remain not infested. They are not blowing up as they have in the past.
