AN EVALUATION OF SHAKING AND DISPLACEMENT METHODS FOR SEPARATING A SAMPLE OF HONEYBEES WITH LARGE HYPOPHARYNGEAL GLANDS FROM THE REMAINDER OF A COLONY
R S PICKARD AND G Y KITHER
Means and frequency distributions of hypopharyngeal land weights were compared in worker honeybees taken from the hive entrance and from central brood frames subjected to shaking or displacement. In samples of 360 bees derived from 4 colonies, the mean hypopharyngeal gland weight per bee was 5.08 ±0.16mg (hive entrance), 8.5± 0.24mg and 9.94 ± 0.55mg (central brood frames, before and after shaking). The difference bewteen the overall means before and after was shown to be significant (P < 0.002) by t - testof the differences between the before and after means of the individual trials. Of the bees on unshaken coombs, 24% had glands < 5mg and 50% of these were displaced by shaking. Displacement procedures gave better selection for large hypopharyngeal glands than shaking. In samples of 180 bees derived from 3 colonies, the mean hypopharyngeal gland weight per bee was 11.71± 0.27mg after 24h displacement to a nucleus box and 11.57 ± 0.25 after 24 h dispalcement to a brood box with its own flight entrance, placed over perforated zinc screen on the parent colony. The displacement procedure using a screened brood box was considerd vto be the best method for isolating bees with gland weights in the range of 6-20mg.