BEEKEEPING
&
DEVELOPMENT 48
How
cerana.in Apis Varroa keeps ch eck by
Otto Boecking, Institut ftir Landwirtschaftliche, Zoologie und Bienenkunde, Germany
Varroa jacobsoni is a predatory mite that lives on
honeybees. In recent years it has been spread throughout the world by beekeepers. It is now a major problem for Apis mellifera. However, Varroa jacobsoni does not show notable disturbance of the Asiatic hive bee Apis cerana, and treatments against Varroa are not necessary. Varroa jacobsoni regularly infest Apis cerana colonies, yet many Apis cerana beekeepers have never seen a Varroa mite in their colonies! Apis cerana and Varroa have built up a balanced host-parasite interrelation in which neither the bees nor the mites completely kill the other species. This is because during their long evolutionary process in Apis cerana
1.
Removal behaviour colonies of Apis cerana the main reason for the restricted population growth of the mite is partially explained by physiological barriers in the worker brood and/or in the mite itself. In
Apis cerana actively defend themselves by removing mite-infested brood. This may also lead to the lack of Varroa jacobsoni in worker
brood.
brood cells, many of these infested brood cells are detected by adult worker bees running over the comb. To hinder the mites from reproducing, the bees uncap these cells and remove the bee larvae or pupae (Figure 1). Consequently the mites fail to reproduce in these cells. If Varroa mites enter Apis cerana worker
(
QS
Figure
colonies the growth of Varroa populations is restricted to the time when drone brood is present. Varroa jacobsoni cannot reproduce in worker brood. In contrast to this, Varroa does reproduce successfully in both drone and worker brood of Apis mellifera bees and can build large mite populations during the whole brood rearing season. For this reason chemical treatments against Varroa are used regularly in Apis mellifera beekeeping world-wide.
Removal behaviour
Figure 3. Grooming behaviour
Further reading BOECKING,O;
et
al (1993) American Bee Journal. 133: 117-119
BOECKING,O, RITTER,W (1994) American 134: 689-694
i
BUCHLER.R;
et
Bee Journal.
al (1992) Exp. Appl. Acarol. 16: 313-319
DELFINADO-BAKER,M; Acarology 18: 315-322
ef al
(1992) International Journal of
FRIES,|; ef al (1996) Apidologie 27: 3-11
KOENIGER,N; PENG.Y C. 49: 54-60
Figure 2. “Non-removai” and plugging the pore
FOUR
et
ef
al (1983) Apidologie 14: 197-204
al (1987) Journal of Invertebrate Pathology.
RATH,W (1992) American
Bee Journal. 132:
329-331
A Bees for Development publication
