We were cruising along last week with
cotton insects kinda quiet. Thrips control was winding down on our latest
planted cotton. The most prevalent observation was the white margined borrower
bug, which could be found in most all fields. They were on cotton with 3 or 4
true leaves up to cotton knee high and squaring.
This week things have changed
dramatically. Not to say every field has insect problems. However, in some
fields, consultants are finding some level of plant bugs, spider mites, aphids
and a few stink bugs. Generally, the older the cotton, the greater the chance
some combination of these pests are present.
Let’s take these pests one at a time.
Some have observed adult plant bugs feeding in terminals of pre-square cotton.
Others report that plant bugs have dropped square retention to below 80% in
cotton that will bloom within 7-10 days. A few stink bugs can already be found
in these older fields. As we know from previous experience, stink bugs will
attack bolls just after the dried bloom drops off if there are no larger bolls
to feed on.
Added to these bug problems are the
presence of aphids and spider mites. Aphids can be found clustering in the
terminals of some plants in fields of older cotton. This is typically the way
an economic aphid infestation usually begins. Spider mites have been treated in
some fields already. Good results were obtained with Abamectin at 10 oz. per
acre. Mites are still on borders of other fields and do not appear to be
spreading yet.
With the combinations of pests present,
it is difficult to control multiple species without a tank mix combination. My
advice to growers, agrifieldmen and consultants would be to narrow your pest
spectrum to the two species that offer the most near term damage potential and
select a chemical or combination that will control those. It is just too early
for me to consider three way tank mix combinations. At this time I believe it
would be wise to target plant bugs (and stink bugs) first and I would place
aphids second. These species can be controlled with a tank mix of two materials
that would be rather inexpensive. A product that will give good control of
plant bugs and stink bugs would be my first choice in the tank. If this product
does not control aphids, I would add one that did.
This would leave the mite issue
unaddressed. I just feel that we need to protect fruit first and deal with
stress from spider mites in the weeks ahead.
There are a number of ways to tackle this
tank mix issue for bugs and sucking pests. One would be a mix of pyrethroid and
imidacloprid. There are too many to mention all at this time. I will be happy
to discuss the various options by phone at 334-332-9501 if you are having
problems deciding what approach to take.
Good luck and I’ll be back as we observe
or hear of other information to pass along.
Ron Smith 