Determination of proteolytic activity in Varroa jacobsoni an ectoparasitic hemophagous mite of honey bees (Apis sp.)

In previous studies, it was demonstrated through immunotechniques that the Varroa resorbs the ingested hemolymph proteins of honey bees (Apis mellifera ) into its own hemolymph. These same proteins are detectable in the eggs of this parasite. To check this undegraded resorption of host proteins, a study of proteolytic activity in Varroa was carried out using homogenates of whole female mites in Tris-HCl-buffer (pH 8.2). Low proteolytic activity could be detected only with the help of very sensitive methods (by using synthetic substrates) and also there were indications that a protease inhibitory factor is present in the Apis hemolymph. A possible explanation of macromolecular uptake of host proteins by Varroa due to an inhibitory factor in the host hemolymph, as well as the low proteolytic activity in the mite, is discussed.