Cotton Insect Report
Following Tropical Storm Cristobal, spider mites are still
building in parts of central Alabama. Spider mite infestations are rarely evenly
distributed throughout the field and are almost always in clumps either near
field edges or randomly throughout the field. Our threshold in the Alabama Cotton
IPM Guide says to treat fields when mites are widely distributed and
mottling of leaves is common. Determining when to implement controls can be
difficult when trying to decide how many ‘hotspots’ suggest mites are “widely
distributed” and justify a spray. Spider mites prefer hot, dry conditions and
typically can be “beaten back” by a rainfall event. Fields with spider mite
hotspots should continue to be monitored after rain, because populations can
build back after several days of hot, dry conditions. Spider mites also tend to
build following broad-spectrum insecticide applications for other pests.
To scout for spider mites, look for leaf stippling or
reddening on the top of leaves. If these symptoms are observed, look on the
underside of leaves for spider mites, which will be a yellowish color with two
black “spots” on each side of its back. Exposing the underside of leaves to the
sun may agitate mites, making them easier to see. Also look for mites one or
two nodes above the most symptomatic leaves as they may have moved up to fresh
leaves. There are a few miticides labeled for use in cotton that can be found
in the Cotton
IPM Guide. Abamectin (e.g., Agri-Mek 0.15EC) at 8-12 ounces per acre is the
most economical option but rotating chemistries is necessary if multiple
applications are needed. Historically, lower rates of abamectin (8-10 oz) have
provided adequate control in younger cotton, while higher rates (12 oz) are
needed later in the season when plants are larger.
Peanut Insect Report
We were recently notified that Nichino America
received a supplemental label for the miticide Portal to use in peanuts. The
labeled rate is 1.0 – 2.0 pints per acre with a minimum of 14 days between
applications. The supplemental label must be in the possession of the user at
the time of application.
