59-05-032 Proceeding

366 Proceedings of the Princess Maha Chakri Sirindhorn Congress thorax (Pdl stage, 17 - 18 days old including the egg stage) (Rembold et al., 1980) were opened and inspected with the aid of a stereo microscope at 40X magnification. For each inspection, the pupa was removed from the cell and examined for mites. Then, the cell itself was examined. Cells which contained only one foundress as indicated by the dark color of her integument were scored for reproduction and non-reproduction. Determinations of mite progeny age and sex were based on a morphological characterization of T. mercedesae nymphal and adult stages according to the descriptions of Delfinado-Baker (1985) and Kitprasert (1984). The expected age of mite progeny at the time the bee in the cell would have emerged was estimated according to the developmental periods described by Woyke (1987). Only worker brood was evaluated since the nests we studied had not very drone brood. The numbers of cells infested with more than one foundress were counted, although the number. A reproductive foundressmitewas one that would have produced at least 1mature daughter before the host bee emerged from its cell. Harbo and Harris (1999) devided non-reproduction into 3 categories : (1) mites that died in the cell before laying eggs, (2) mites that were alive in the cell but did not lay eggs, and (3) mites with female progeny that were too young to mature before the host bee emerged from its cell. In this study, we could not distinguish between categories one and two since the combs were frozen prior to examination. We assumed that most of the mites were dead because of being frozen. The fecundity (number of progeny produced by reproductive mites) of reproducing mites from cells infested by one foundress mite was also recorded. Results The average number of cells per colony which were infested with T. mercedesae and contained Pdl or older pupaewas 32.5. About 0.5%of these infested cells were infestedwithmultiple foundresses. Cells containing multiple foundresses also contained an average of 1 daughter per foundress (Table 1). Table 1 Numbers of T. mercedesae daughters in A. dorsata worker brood cells in developmental stages of dark brown eyes with light pigmented thorax pupae and older having more than one foundress and the average reproductive rate in multiply infested cells. Colony Number of cells inspected Number of cells infested by more than 1 foundress Percentage of cells infested by more than 1 foundress Number of foundresses Number of daughters Number of daughters per multiply infested cell 1 693 3 0.4 6 3 1.0 2 569 4 0.7 9 3 0.8 3 672 2 0.3 4 2 1.0 4 517 3 0.6 6 3 1.0 5 814 3 0.4 6 3 1.0 6 1,275 5 0.4 11 4 0.8 7 783 2 0.3 4 2 1.0