The need for using laboratory tests in breeding honeybees for improved honey production
C. P. Milne, Jr
Seasonal honey production and laboratory measurements of worker hoarding behaviour, longevity (length of life), pupal weight and corbicular area in honeybees (Apis mellifera) were recorded for an apiary of about 18 different colonies for each of 6 years. An analysis of variance indicated significant differences between years for both honey production and results on each laboratory test. Corbicular area was an important component of, or significantly correlated with, colony honey production in 2 of the 3 years it was examined. Hoarding behaviour, longevity and pupal weight were important in 1, 3 and 5 of 6 years, respectively. Of the 4 sets of laboratory tests, only results on the test of hoarding behaviour were not significantly correlated with colony honey production when all 6 years were combined. Therefore, over a period of years, these tests apparently measured significant components of colony honey production. Of the 6 possible phenotypic correlations among the 4 laboratory tests, coefficients for all but hoarding behaviour with corbicular area were significant, implying the influence of a number.of common genes. As all 6 correlation coefficients were positive, it should be possible to select simultaneously for the 4 components represented in the laboratory tests. Because there is wide year-to-year variation in the effects of the environment on honey production (reflected in variation in significance for correlations between honey yields and individual tests), it is unlikely that field-tests of full-strength colonies alone will be reliable for identifying superior breeding stock to achieve genetic improvement in honey production. The 4 laboratory tests, and others yet to be developed, should be employed to achieve genetic improvement in honey production. These conclusions, based on estimates of the phenotypic correlation, would be strengthened greatly by additional evidence from genetic correlation estimates.