Defense mechanisms of Apis dorsata fabricius and ars primorsky honey bee Apis mellifera linnaeus to the bee mite Tropilaelaps clareae delfinado and baker

Abstract

Six new and 8 established colonies of Apis dorsata were collected in Samut Songkhram, Thailand, between April 2000 and September 2002 to investigate their infestation by Tropilaelaps clareae Delfinado and Baker. No mites were found in the 6 new colonies. The 8 established colonies had 2-119 mites in the sampled sealed brood, and 3 of 8 established colonies had 1-11 mites on the adult bees. Sixteen established and 13 deserted colonies of A. dorsata were also collected from different locations in Thailand, from March 2000 to October 2002, to determine for mite infestations. The sixteen established colonies had 0-146 T. clareae in the sampled capped brood, and 0-647 mites were found in sealed brood of the 13 deserted colonies. The average infestation rate was 0.3% on the adult bees, and 1.8 and 13.5% in sealed brood cells of the established and deserted colonies, respectively. Debris from two A. dorsata colonies (1 and 2) in Chiang Mai and three A. dorsata colonies (3. 4 and 5) in Samut Songkhram was collected between May 2000 and July 2002. A total of 9,163 and 1,806 T. c/areae were recovered from colonies 1 and 2. respectively, The number of mites collected in the debris of colonies 3. 4 and 5, was 10, 1 and 0. respectively. The percentage of injured mites in the debris from these A. dorsata colonies was 93.8%. Eleven A. dorsata, 10 ARS Primorsky (A. mellifera) and 10 Thai commercial colonies (A.mellifera) were used to investigate rates of non-reproduction by Tropilae/aps mites infesting brood and the number of progeny produced by reproductive mites. The mean percentage of non­ reproductive mites on the worker pupae of the A. dorsata colonies (65.2±5.1%) was significantly higher than that the mites in the Thai (50±3.8%) and Primorsky (48±5.2%) colonies. The mean percentages of non-reproductive mites in the Primorsky and Thai colonies were not significantly different. The numbers of progeny produced by reproductive mites in the A. dorsata (1.7±0.4). Thai (1.8±0.3) and Primorsky (2.0±0.3) colonies were not significantly different. Ten ARS Primorsky and 10 Thai colonies were studied regarding their potential resistance to T. clareae. The experiment was conducted in Chiang Mai during November 2001- February 2003. The average infestation rate of T. clareae on the Primorsky brood (18.5±2.6%) was significantly higher than that of the Thai brood (11.4±1.5%). The mite infestation rate on the adult bees (0.5±0.1 - 0.8±0.2%). the average number of mites through time in the test colonies (871.5±179.5 - 954.9±184.6). the mite number per infested cell (2.4±0.2 - 2.9±0.2), the injured mite percentage in the debris (70.3 - 72.7%), the rate of removal of freeze-killed brood (82.6±5.8 - 85.5±5.4%) and the colony longevity (4.6±0.5 - 6.2±0.8 months) of the Primorsky and Thai colonies did not significantly differ.