|De Guzman, Lilia|
Submitted to: Apidologie
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2012
Publication Date: 9/1/2012
Citation: Khongphinitbunjong, K., De Guzman, L.I., Burgett, M.D., Rinderer, T.E., Chantawannakul, P. 2012. Behavioural responses underpinning resistance and susceptibility of honeybees to Tropilaelaps mercedesae. Apidologie. 43(5):590-599. Interpretive Summary: Tropilaelaps mercedesae is a serious pest of Apis mellifera in Asia. Tropilaelaps has been reported to have the ability to withstand the longest international flight. Thus, this parasitic mite species has the potential of becoming the most serious parasite of A. mellifera worldwide. We studied the behavioral responses of A. cerana, A. dorsata and A. mellifera to T. mercedesae. Our results showed that A. cerana was the most successful in removing phoretic mites which was probably due to a combination of auto-grooming and body-shaking. A. dorsata and A. mellifera both displayed auto-grooming but A. dorsata was more effective. Likewise, A. cerana and A. dorsata quickly performed grooming actions toward the introduced T. mercedesae. A. mellifera took the longest time to react against T. mercedesae. A. cerana is not the original host of T. mercedesae. Hence, we hypothesize that the auto-grooming and body-shaking of A. cerana may be evolutionary responses to selection pressure exerted by varroa mite parasitism.
Technical Abstract: The behavioural responses of Apis cerana, A. dorsata and A. mellifera to T. mercedesae were compared using two laboratory bioassays: cohorts of unknown ages of worker bees and single-bee bioassays. For the group bioassay, combless cages containing 50 worker bees and 10 adult T. mercedesae were used. After 6 h, nearly 2/3 of the inoculated mites on A. cerana were removed compared to only about 1/3 for A. dorsata and A. mellifera. The majority of the mites fell after 24 h from A. cerana, after 36 h from A. dorsata and after 48 h from A. mellifera. Higher proportions of injured mites were also observed in cages with A. cerana (38.3 ± 12.9%) and A. dorsata (33.9 ± 17.4%) than in those with A. mellifera (19.5 ± 7.2%). The rapid and successful mite removal in A. cerana may be due to a combination of auto-grooming and rapid body-shaking. Likewise, A. cerana (39.4 ± 13.2 sec) and A. dorsata (44.9 ± 19.2 sec) responded to the presence of T. mercedesae more quickly than did the A. mellifera (188.4 ± 63.9 sec) when individual bees were challenged with one female T. mercedesae. We also found that phoretic T. mercedesae used specific attachment sites on host bees. The propodeum/petiole region of all three honey bee species was used most often by the mites. Also, some mites occupied the wing base area of A. dorsata and A. mellifera.