No abstract

Observations for 3 seasons during the blossom period of kiwifruit (Actinidia chinensis Planch.) cv. 'Hayward' indicated that honey bees (Apis mellifera L.) were by far the most numerous of the insects visiting the flowers in orchards in which honey bees had been introduced. Hairy colletid bees (Leioproctus spp.) were observed on the flowers of 4 of 7 orchards in 1978-79, 6 of 9 in 1979-80, but none of 9 in 1980-8 1. However, their numbers were generally so low that, except in 1 orchard in 1978-79, and 2 in 1979-80, their effect on pollination was probably insignificant. Bumble bees (Bombus spp.) and other insects were too few to be of importance in the sites observed. Honey bee visitation to kiwifruit flowers in 1978-79 was reduced by competition from other pollen sources, which might explain the poor fruit size that season. Competition was minimal, and there was good bee visitation in 1979-80 (when fruit size was generally good) and in 1980-8 1 (when it was unsatisfactory). In 1980-81 there were more flowers and consequently more fruit, in all orchards compared with the 1979-80 season, and this physiological load probably caused some of the reduction in weight. In 1980-81, 32.7% of fruit weighed less than 72 g, even though fruit less than 93 g contained significantly more seed than in the previous 2 seasons. This suggested that pollination was satisfactory, but that adverse weather conditions may have retarded fruit growth. Even in poor seasons some orchards achieve excellent results, and in good seasons some orchards have very poor results, which suggests that factors such as position of male vines relative to females, cultural methods, and orchard microclimates may be important.

ABSTRAcrToxicity tests showed that the nectar of the yellow kowhai (Sophora microphylla Ait.) frequently has a narcotic effect on honey bees. Only adult bees are affected.Mortality of narcotised bees may occur, especially if they are exposed to the low temperatures common in the spring. Extracts of S. microphylla seeds are toxic to mice. Narcosis and mortality, resembling that caused by the nectar, result if bees are dosed extracts of seeds and wood. Narcosis and mortality of bees appear due to the alkaloids of S. microphylla reaching the nectaries.Beekeepers should consider resiting apiaries if severe mortality due to kowhai poisoning occurs.

No abstract

Over two seasons, observations were made on the role of the honey bee and the bumble bee in the pollination of Montgomery red clover (Trifolium pratense L.) in the South Canterbury, Mackenzie Country, North Otago, and South Otago districts of New Zealand.Conclusions were as follows:-(a) Honey bees and bumble bees were the only insects of importance as pollinators. (b) For most crops studied honey bees appeared to be more important than bumble bees. (c) The short-tongued bumble bee (Bomhus terrestris L.) was of much less value as a pollinator than were long-tongued bumble bees or honey bees. (d) Crops were pollinated as effectively by honey bees as by the two main species of long-tongued bumble bees. (e) In general, very low honey bee densities, expressed as bees per 10,000 flowers, were associated with heavy competition from other nectar sources. (f) Expressed as bees per 10,000 flowers, average concentrations of both honey bees and long-tongued bumble bees were significantly higher for crops with pollination values of 69% or more than they were for crops with values of less than 69%.