The past 10 days have been characterized by heat, drought, scattered thunderstorms, aphids, and in some cases spider mite decisions. Some areas have received one or more rainfall events of 1 to 3 inches or more while others are still suffering extreme drought. Some of these storms have brought high winds, downed trees, demolished buildings and hail.
been rather quiet overall. Many field men have made aphid treatment decisions
with significant acres treated. In at least one incidence, both aphids and
mites were at treatment levels. Other more sporadic fields have needed adult
tarnished plant bug controls. In the majority of cases the plant bug population
has now shifted to immatures. In these cases field men need to switch from
sweep nets to drop cloths to quantify these immature plant bugs. Two or three immatures
per drop could be considered a threshold level requiring treatments, especially
if “dirty” blooms are present. Pinhead square retention is no longer the best
way to look for plant bug damage since they spend more time down in the canopy
feeding on larger squares (which later become dirty blooms).
I have not
had any calls yet, but field men in the southern areas of the state need to pay
attention to stink bugs since our oldest fields are now at week three, four or
more of bloom. Weeks three through six of bloom is when stink bugs are most
damaging. A good threshold for treatment during this period is 10-15% internal
damage to quarter diameter (still soft) 10-12 day old bolls. Look for brown
areas near the seed and warts on the
inside boll wall where stink bugs have penetrated in search of a protection source
in the form of developing seed. If the population of stink bugs is primarily
the southern green species then we have choices of both pyrethroid and
phosphates. However, as most likely the case, the population may be
predominately brown stink bugs. Here we would need a phosphate such as Bidrin
or either a high rate of bifenthrin and get decent suppression.
just received of an increase of small larvae on peanuts in south-central
Alabama. My guess would be that they are tobacco budworms. By July 15, newly
hatched larvae will more likely be corn earworms.