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Management of Spring Vegetable Pests
Southwest Florida Research and Education Center
February 16, 2000
Sponsored by:
University of Florida/Institute for Food and Agricultural Sciences
Dow Agrosciences
Prepared by: Galen Frantz

Phil Stansly presented the results of insecticide tests conducted during the Spring and Fall of 1999. The spring tests have been published in the Proceedings of the Florida Tomato Institute (September 1999) and the results of the fall tests were presented in a handout at tonight's meeting. A copy will be circulated at Bari Street. Additional copies will be forwarded to Jupiter for distribution to Homestead and Quincy. He first presented data on the impact of Tomato Yellow Leafcurl Virus (TYLCV), which clearly showed that the time of infection is the critical factor in determining yield effects of this disease. The earlier infection occurs, the greater the yield reduction. The disease does not have a significant impact on fruit size, but reduces the number of fruits produced. Therefore early control of SLW is most critical. Colored mulches can have an effect on early infestations of tomato by silverleaf whiteflies (SLW). Highly reflective Mylar mulch showed the greatest reduction in early infestation, but lowered soil temperatures, resulting in reduced plant growth and productivity. These mulch tests are being re-run this spring. Soil application of imidacloprid (Admire) and thiomethoxam (Actara from Novartis) is much more effective than foliar application for control of SLW adults. Both active ingredients performed equally well. Pymetrozine (Fulfill from Novartis) was effective against immature SLW, but did not control adults. Thiomethoxam was effective against SLW at application rates of .0125 and 0.088 lb ai/A, compared to 0.25 lb ai/A for imidacloprid.
Spintor, Javelin and Ambush were evaluated for control of melonworms and pickleworms on zucchini squash. The pickleworms were evaluated by examining blooms, as this is the usual site of hatching. In these tests Spintor and Javelin provided better control than Ambush, with Spintor performing best. Yields were highest in the plots treated with Spintor.
Vydate and Actara were compared for control of pepper weevil. Control with Actara was significantly better than with Vydate, although both treatments were better than the untreated check. Actara was applied twice at 0.085 lb ai/A, compared to six applications of Vydate at 0.5 lb/A. The difference in the number of applications needed for control may be important for scheduling hand labor operations. Actara is expected to be available sometime next season.
For control of diamondback worm, 4 oz Spintor 2SC provided best control followed by 2 qt of either Match or Javelin. Spintor's label restricts the number of applications in a cabbage crop to three.
All materials tested provided some level of tomato pinworm control. Spintor provided the best control, Confirm/Intrepid and Mattch reduced populations somewhat, but not as much as Spintor or a high rate of Agrimek. Spintor, an acetylcholine exciter, causes involuntary muscle contractions and can take a week to kill. Coverage is the key to success with using Spintor. Silicone spreaders, crop oil concentrates or 80/20 surfactants improve Spintor efficacy. A maximum of 29 oz of Spintor is legal for each crop. Only three consecutive applications are allowed for each crop. Two consecutive applications for leafminers or pinworms are recommended. Three consecutive applications are allowed for other pests. A 2-oz maintenance rate can be applied, but the 4 to 6-oz rates are more commonly used. With Spintor, beet armyworms die more easily than southern armyworms at an older age. Applying Spintor for third instar armyworms may work, but is not recommended. Loopers are easily controlled. Western flower thrips stay on the plant for a longer period than do the Florida flower thrips. The key to control of thrips with Spintor is multiple applications. Aphids, scale insects, true bugs, most beetles and mites are not controlled with Spintor.

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