June 5, 2001 Ornamental Pest Management Update Meeting Palm Beach, Florida Notes by: Loren Horsman Dr. Lance Osborne: Mealybugs are a major issue involving at least one call per week. Three new species are spreading: Root mealybugs in containerized palms, Longtailed mealybugs, and Mexican mealybugs. There is a quarantine issue for these three mealybugs. Ornamentals contaminated with any of the three new mealybugs may not be able to leave the state. Osborne also mentioned the citrus mealybug is still out there and is difficult to control. He thinks the loss of Temik has increased mealybug problems. For now, there are very few effective sprays for mealybug control. The control of mealybugs interferes with other biological control programs, thus making it difficult to initiate a program. The proper identification of mealybugs is essential: Citrus mealybug - Planococcus citri- has a single stripe down its back. Mexican meal bug- Phenacoccus gossypii- huge host range, very rapid development. Solenopsis mealybug- toxin associated with feeding damage causes leaf deformation. Pink hibiscus mealybug- found in California but not in Florida, infested plants have leaf distortion. Pseudococcus longispimus- has two long tails. Banana mealybug- Pseudococcus elisae- similar to long tail mealybug. Striped mealybug- Ferrisia vergata- two dark stripes. Osborne is working on developing biological control programs for mealybugs using parasitoids. Several species need to be used for good, effective control. Leptomastix dactyles and L. normis- very effective but only on citrus mealybug. Anagyrus fusciventris - cycad mealybug parasitoid. A. Sp. - Mexican mealybug parasitoid, one grower is rearing this parasitoid in buckets to control Mexican mealybugs in his nursery. Ladybug predators: The mealybug destroyer- larvae look like mealybugs. Diomus austrinus - a ladybug beetle that eats many different mealybug species. Growers must understand that it takes a while for parasitoids and predators to become established. Correct identification of mealybugs is key to selecting the correct biological control agent. Because female mealybugs do not fly, a bucket full of them can be used to rear and propagate parasitic wasps. The following are products used in the control of mealybugs: Dursban, Orthene, Talstar, Distance, Marathon, and Closure (last one may cause phytotoxicity). None of these products gives more than seven to ten days of mealybug control. All but Marathon can interfere with biological control agents. Spider mites: Osborne believes spider mites can only be controlled effectively by scouting. Thirty-six percent of all ornamental pesticides are applied to control spider mites. Male spider mites are identified by their pointed abdomen. A high number of males present indicates a big problem. The Lewis mite, Tumid mite (red with spots) and the broad mite (very fast development time, phoretic movement into ornamentals by whiteflies and thrips) are some of the most common and injurious mites in ornamentals. Control: Grower must develop a matrix of miticide applications. A miticide can be contact with little residual or a seven to twenty-one day residual. They can target eggs, nymphs, or adults. The product you chose depends on what is happening in your system. The most common predatory mite is Neoseiulis spp., N. californicus feeds on broadmites. Felitia spp.- predatory midges that feed on mite immatures and eggs. Six spotted thrips are good mite egg predators and the Franklinthrips sp.- look like an ant, can fly and move to other areas and feed on all kinds of mites. Dr. Catherine Mannion: Not all snails and slugs are pests since they also feed on algae and fungi. Any snails on plant material will be a problem to ship. She knows of three shipments to Arizona rejected because of the presence of snails - Bradybaenu similaris. As a rule of thumb, darker snails are more resistant to chemical controls than lighter colored ones. Also, they are more resistant during the reproductive stage. Product Updates Phyton 27 (bactericide & fungicide): Labeled for perennial and bedding plants, dip and foliage application. It is a CuSO4 material, systemic, odorless, and invisible for control of powdery mildew and botrytis. Use in nursery or landscape as a foliar spray or drench; can be phytotoxic if used with Plyac. Hexygon (miticide): Acts as an ovicide/larvacide and inhibits the female mite from producing eggs. It is safe for beneficials, but has no activity on broad mites. Must be applied at first mite egg finding at the rate of two ounces per one hundred gallons of water. Manufacturer claims thirty days of mite control. Ultraflora (miticide): Reduced risk product with the active ingredient of milbemecin A1 and A4. Acts as an ovicide/larvacide/adulticide and inhibits female mite from laying eggs. Ovation (miticide): New miticide that will control two spotted spider mite, and broad mites. Lasts for thirty to forty-five days, can only be applied once per year, must be applied before infestation takes place.