Pest Alert: Silverleaf Whiteflies Moving into Cotton
Photo credit: Scott Bauer, USDA Agricultural Research Service, Bugwood.org
Silverleaf whitefly feeds on plants and can stunt growth and cause defoliation. Honey dew created by their feeding also can cause “sticky cotton,” which drives down lint quality.
2020 has been a very busy insect year, starting with plant bugs and spider mites and, most recently, a large bollworm flight. In controlling pests like mites and bollworms, disruptions in beneficial insect populations coupled with hot and dry conditions can give ground to the silverleaf whitefly, says Wilson Faircloth, Syngenta Agronomic Service Representative in GA.
Silverleaf whitefly is a crop-crossing pest that can quickly infest fields and reach economically damaging thresholds. Often, whitefly outbreaks occur when natural enemies have been diminished or disturbed. Faircloth says that whiteflies are not an every-year pest, but when they do come along, they can be very difficult to manage.
In recent pest patrol alerts, entomologists in GA and AL warn growers that this difficult-to-manage pest infested historical areas and is spreading across more acres. These sucking pests feed on plants, leading to reduced plant health and defoliation, as well as potential lint quality deductions due to sticky honeydew secretion.
GA entomologist Phillip Roberts, Ph.D., says whiteflies are on everyone’s radar. Heavy rainfall can suppress adults and delay the need to treat as infestations continue to spread. However, where whiteflies are entrenched, rains only provide temporary relief. According to Roberts’ guide, Scouting Silverleaf Whiteflies in Cotton, leaves are infested if there are 5 or more immatures on the underside. Treatment is recommended when 50% of sampled leaves are infested with immature silverleaf whiteflies.
Managing silverleaf whitefly in cotton can be tricky because multiple factors complicate treatment options, including beneficial populations, speed of control and length of residual control. Roberts urges growers to scout their fields and be timely with applications if whitefly numbers exceed threshold, especially when using insect growth regulator products. Roberts recommends treating with a contact, systemic product when applications will be made late.
For silverleaf whitefly control in cotton, growers must implement a timely integrated pest management program that simultaneously offers flexibility and effective control.
With silverleaf whitefly in the system, growers should diligently scout fall vegetable crops.
Sign up for the 2020 Pest Patrol alerts to receive timely text updates on insect and disease threat levels, outbreak predictions and more from leading experts and Syngenta agronomic service representatives.
Sign up for the Know More, Grow More Digest to receive twice-monthly agronomic email updates pertinent to your area.
All photos are either the property of Syngenta or are used with permission.
Syngenta hereby disclaims any liability for Third Party websites referenced herein.