Watch for a new insect invader in Florida

Watch for a new insect invader in Florida

By Wayne Hobbs

UF/IFAS Environmental Horticulture Agent

Clay County

With a large amount of agricultural and horticultural production, Florida plays host to many plant diseases and pests. In addition to the aphids, mites, and mealybugs, we do sometimes get a new pest or a mutation of an established species.

This has occurred with the Q-Biotype Whitefly.

According to University of Florida IFAS research, the sweet potato whitefly or silverleaf whitefly (Bemisia tabaci), the species has been in Florida since the early 1900’s but in April 2016 the Q-Biotype whitefly made the news as it spread to several counties throughout Florida including Duval County and several more to the south. What makes the pest newsworthy is the fact that it is much more resistant to pesticides than other biotypes.

The insect itself is fairly inconspicuous, as it is a white, gnat like insect. To monitor for whiteflies, shake the plant to see them fly away or look on the underside of the leaves. The sweet potato whitefly is smaller than other landscape whiteflies, has a yellowish colored head and body and has no bands or spots on the leaves. They also secrete honeydew, a waste product from feeding on plants, which will often lead to black sooty mold.

The insects are mostly found on hibiscus, lantana and crossandra in the landscape but may also feed on tomatoes, squash, watermelons, beans and other vegetables. It is also known to spread viruses that significantly reduce vegetable crop yields and is expensive to control by farmers, making it of high concern.

However, do not panic about the insect, as it is not causing major damage in the landscape but the spread needs to be stopped. Research is underway at the University of Florida and there are things that you can do as a homeowner to reduce populations and keep it contained.

First of all, if you have infested plants do not transport the plants or clippings. If plant clippings are infested, securely bag them and place them in the garbage instead of leaving them as yard waste. Most landscape plants that have the pest can be treated with insecticidal soap or horticultural oil such as those containing Neem oil, paraffinitic oil, vegetable oil or potassium salts of fatty acids.

For larger plants where these applications are not practical, use systemic pesticides that are labeled for landscape plants and whitefly control containing Dinotefuran or Acetamiprid. These are usually applied at the base of the plant to the soil and are long lasting. Other pesticides should be avoided unless they have been shown as effective against the Q-Biotype of the sweet potato whitefly.

With all pesticides, follow the label exactly. The pesticide label is the law and is there to protect you, wildlife and the environment from possible harm. Also, make sure to check the label for plant sensitivity as some products may cause harm to certain species.

If you have any more questions about the whitefly, composting or any other lawn or landscape topics, contact the University of Florida/IFAS Extension Office online at http://www.clay.ifas.ufl.edu, follow us on Facebook, or call by phone at (904) 284-6355.