(G43) SOUTHERN WAX MYRTLE: Myrica cerifera L. CO-CO PLUM: Chrysobalanus icaco L. EFFECT OF BEAUVERIA BASSIANA ON LOBATE LAC SCALE INFESTING ORNAMENTALS, 2004 C. L. McKenzie USDA-ARS, U. S. Horticultural Research Laboratory 2001 South Rock Road Ft. Pierce, FL 34945 Phone: (772) 462-5917 Fax: (561) 462-5986 E-mail: cmckenzie@ushrl.ars.usda.gov Catharine Mannion Tropical Research and Education Center Institute of Food and Agricultural Sciences 18905 SW 280 St Homestead, FL 33031 Phone: (305) 246-7001 ext. 220 Fax: (305) 246-7003 E-mail: cmannion@mail.ifas.ufl.edu Lobate lac scale: Paratachardina lobata (Chamberlin) Virtually unknown before its introduction into Florida in 1999, the lobate lac scale has spread quickly and is now reported on over 160 economic and native species representing 49 different plant families. This little known scale has become one of the potentially most devastating pests of trees and shrubs in the Florida history and has been identified by the nursery industry as one of their top research priorities. BotaniGard ES mycoinsecticide (Beauveria bassiana) was evaluated for efficacy against lobate lac scale on two susceptible ornamental hosts, southern wax myrtle and co-co plum. Lobate lac scale were field collected from multiple sites and various host plants across south Florida by cutting infested twigs into 8- 10 inch length segments for easy storage in emergence containers. Twigs were held and monitored for crawler emergence. When crawlers were noted, twigs were divided into 2-inch lengths and placed at the base of each test plant so that crawlers would independently transfer and settle on the test plant naturally for mycoinsecticide evaluations. Speedling trays of southern wax myrtle and co-co plum were obtained from a local nursery and examined for contamination (pest or disease). Clean transplant cells were broken up into single plants (approximately 25 cm tall) and planted into Ray Leach “Cone-tainer” single cell systems. Cone-tainers were placed in half racks so that the rack could be placed in a water holding tub. All plants received the same water and fertilizer amounts at the same time by filling up the holding tub above the bottom of the cone tubes. Water was siphoned from the holding tub after watering (approximately 2-3 h), but kept to a one inch level remaining in the tub to insure humidity was kept at an acceptable level for proliferation of lobate lac scale. Soil and nutritional requirements were satisfied by standard ProMix Bx potting medium and fertilized weekly with Peter’s Professional General Purpose FLA Special 20-10-20. Two age groups of lobate lac scale were evaluated on each of the ornamental hosts. Large lobate lac scales (165 -221 d old) were seeded between 9 Mar and 3 May and small lobate lac scales (97 - 116 d old) were seeded between 21 Jun and 9 Jul. BotaniGard ES mycoinsecticide was applied according to the label as a rooted cutting dip at the recommended high rate (1 oz /gal water) and Downloaded from https://academic.oup.com/amt/article-abstract/30/1/G43/309554 by guest on 22 May 2020