Aphid numbers continue to build, while most insects numbers remain at moderate levels

Insect conditions have not changed greatly in the past week or so. Aphids have continued to build in more fields. All other insects are low to moderate levels (mostly sub-threshold). These include plant bugs (including a few clouded plant bugs coming into the mix), bollworms, tobacco budworms and stink bugs. Most growers do not have enough of a single species to apply controls for. The two biggest surprises at this point in the season are the low number of bollworms and the low number of stink bugs in most fields. Numerous fields of conventional cotton still have less than 2 bollworms per 100 plants. Boll damage to stink bugs is less than 10% in most fields.

Most of the state has had abundant thunderstorms for several consecutive weeks. Cotton yield prospects have improved greatly and, if conditions continue, numerous fields have two bale plus potential. The two biggest limitations we now have are fields with “skippy” stands and too much late maturing cotton.

Cotton Insect Management 2011

Points for Discussion:
1. Low Input System - Conventional vs. Technology
2. Evolution of Bt Cotton - Various Genes Involved
How do they compare and what is in the future?
3. Phase Out of Temik
What will be the greatest impact?
4. Stink Bug Research Towards a More Rapid Survey Technique
Factors that influence external vs. internal stink bug boll damage.

5. New Damaging Insects
A. Plataspid (Kudzu) Bug

B. Brown Marmorated Stink Bug

C. Redbanded Stink Bug


A. Plataspid (Kudzu) Bug

 Native to Asia

First detected near Athens Georgia in the fall of 2009

Has since spread over much of Georgia, South Carolina and into a few counties in North Carolina and Alabama

Feeds primarily on legumes

Reduced soybean yields by about 20% in 2010 test fields in Georgia

Feeds on stems and leaves

Has high reproductive potential

Can be controlled with pyrethroids and other chemistry

Is a public nuisance problem in fall of the year as they enter homes and buildings to hibernate.

B. Brown Marmorated Stink Bug

First discovered in Pennsylvania in late 1990s

Native of Asia

Big problem in specialty crops in mid-Atlantic states (grapes, apples)

Caused 60-90% loss in peaches and apples in 2010

Called Interstate Bug since it spreads by trucks and campers

Has wide host range - feeds on about everything

Have been found in three Alabama counties in late 2010

Has long proboscis so can go through the husk of corn

Pecans may be huge host in the southeast

Causes more damage per bug on soybeans than green or brown stink bug species

Expect to be economic pest of cotton

Will likely have heavy field edge or border damage
Invades homes for hibernation sites in the Fall

3. Redbanded Stink Bug

Native to South America (Brazil)

First found in Louisiana in 2000

Observed on soybeans in Baldwin County, Alabama in July 2010

Is sensitive to winter temperatures below 20 degrees F

Has high reproductive potential

Is primarily a legume feeder

Can cause heavy damage to soybeans

Feeds earlier and more aggressively than other stink bug species

More difficult to kill than Southern green stink bug

This concludes Week Five of Cotton Insect Management 2011. The slide show can also be viewed at http://www.aces.edu/anr/crops/documents/CottonInsectManagement2011RonSmith.pdf