Whitefly Alert

The situation

This spring is shaping up to be a bad season for whitefly and attendant problems pm tomato of TYLCV (virus) and irregular ripening.  Already we are seeing irregular ripening problems in late picked fall tomatoes (Figure 1.  What factors are causing this situation?

  1. Perfect weather for whiteflies (dry and warm)
  2. Poor market causing growers to hold crops that may not be adequately sprayed and overlap with spring crops.

As a result, whiteflies that built up in fall crops are moving to spring crops carrying virus with them.  Irregular ripening is a physiological disorder unrelated to virus but caused by feeding of whitefly nymphs, not adults.  The threshold for irregular ripening is 1 nymph per 2 leaflets.  Nymphs (Figure 2) are best monitored on the underside of the lower (5-7th node) leaves.

What needs to be done? 

  • Kill any old tomato crops a quickly as possible.  Spray first with a tankmix of pyrethroid and malathion to kill whiteflies in the old crop.
  • Treat seedlings with a systemic insecticide in the transplant water.  If on drip, make a second soil application in 30 days using a systemic insecticide of different mode of action (Table 1).
  • Scout crops every week and apply insecticides as needed to maintain control.  Target nymphs once the threat of immigration from old crops has passed (Table 2).

Table 1: Systemic insecticides applied to soil for whitefly control


Table 2


Figure 1. Irregular ripening of Roma tomatoes

Figure 2, Third and fourth instar whitefly nymphs (Bemisia tabaci) on tomato.

For more information contact:  Phil Stansly, University of Florida/IFAS/SWFREC, 239-658-3427/ 464-7395 pstansly@ufl.edu

Monica Ozores Hampton, University of Florida/IFAS/SWFREC, 239-658-3412305-318-9949, ozores@ufl.edu


Screwworm larva showing rasping mouthparts. Photo credit: John Kucharski

On Monday, state agriculture officials announced that the parasite that eats the flesh of living animals had been found in a stray dog in Homestead. As a precaution officials will release sterile flies in order to eradicate the pest.


Click on the following link to read Miami Mayor Carlos Gimenez’s statement regarding New World screwworm:



Galleries of Emerald Ash Borer. Photo credit: Kelly Oten, North Carolina Forest Service, Bugwood.org

Effective immediately, the Animal and Plant Health Inspection Service (APHIS) is adding White County in Tennessee to the list of regulated areas for the emerald ash borer (EAB).

NAPPO Official Pest Report

USDA APHIS Emerald Ash Borer Federal Regulations and Quarantine Notices



Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org

Effective October 28, 2016, the Animal and Plant Health Inspection Service (APHIS) removed the Mexican fruit fly (Mexfly) Anastrepha ludens quarantine in the San Ygnacio area of Zapata County, Texas.

NAPPO Official Pest Report

USDA APHIS Fruit Flies Quarantine Information


Sterile male screwworm fly marked with a numbered tag to study fly dispersal, behavior, and longevity. Photo credit: Peggy Greb, USDA-ARS.

From the USDA-APHIS website:

The presence of New World screwworm (Cochliomyia hominivorax) in Key deer has been confirmed by USDA-APHIS in Big Pine Key, Florida. New World screwworms are fly larvae (maggots) that can infest livestock and other warm-blooded animals, including people.

See alert here: USDA Confirms New World Screwworm in Big Pine Key, Florida



Key deer. Photo credit: Marc Averette, creative commons.