Control of Varroa Mites on Caged Honey Bees, 1993

Live bees were obtained from the brood nests of colonies in an apiary heavily infested with Varroa mites near Cocoa, FL, 13 Mar. Approximately ¼ liter (225 g) of bees from each colony (about 1700 bees) were placed in each of sixteen 20.8-liter screen cages (27.3 × 27.3 × 27.9 cm), equipped with sugar syrup feeders. Caged bees were maintained in a darkened airconditioned trailer (70°F) at the U.S. Horticulture Laboratory, Orlando, FL. Cages were randomized into 3 treatment groups and 1 control group (4 cages per group). A sample of approximately 275 bees (121-346) from each cage was sacrificed to estimate the initial level of mite infestation before treatment. Cages were placed over sticky paper to trap mites that fell. Amitraz smoke-treated cages were placed into a chamber (0.19 m1) for 1 h, where they were exposed to smoke from a strip of filter paper (2.54 × 9 cm) soaked in 15% KNO, and impregnated with 20 mg of Amitraz (Varamit®, sold in the former Yugoslavia). Apistan® package bee strips (Zoecon, Inc.) (a plastic strip, 3.18 × 12.7 cm, containing 2.5% fluvalinate, 21.1 mg AI) were hung from the top of cages near the feeder. Fluvalinate smoke (containing 16.7 mg AI) was administered in the same manner as Amitraz smoke. Cages were placed on shelves over sticky paper for 5 d to trap mites that dropped. Sticky papers were changed at 1, 24 and 120 h post-treatment for mite counts. Exact counts were made of live bees and mites remaining in cages at the conclusion of the 5-d test.