Insect pollination in the New Zealand mountain flora

Abstract

A wide variety of lepidopterans, bees, flies, and beetles visit the flowers of most species of New Zealand montane plants. Of the 82 plant Species which were well-collected, 4 species (Pterostylis sp., Pratia macrodon, Mazus radicans, and Dracophyllum acerosum) exhibited specialised pollination relationships with an insect order; 3 species (Cyathodes fraserii, Microris unifolia, and Thelymitra venosa) are not apparently visited by insects; and the remaining 7S species are visited by a variety of insects in 2 or more orders. Introduced plant species in the Composite family are visited predominantly by introduced bumblebees. Bees in the genera Lasioglossum and Leioproctus are abundant flower visitors. The most common lepidopteran flower visitors are in the families Noctuidae, Geometridae, and Pyralidae, and the genus Lycaena. Dipterans, in particular tachinids and syrphids, are numerically the most abundant flower visitors, and visit a wide range of species. The syrphid Melangyna novaezelandiae visits the flowers of more plant species than any other flower visitor. Beetles are typically not abundant, and do not move often between flowers. Species in the genus Hebe might be expected to have different insect pollinators from species in the Composite family. because of the quite different floral characteristics in these groups. However, there is no general difference in the insects visiting the flowers in the genus Hebe, the family Compositae. and the remaining species. indicating a lack of specialisation for particular pollinators. Individual flowers of most species last more than 4 days, so that several consecutive days of bad weather need not prevent a flower from being pollinated. There is no obvious relationship between the biogeographical Origin of plant species and the types of insects visiting its flowers.

Keywords:

• pollination
• reproductive behaviour
• New Zealand flora
• mountain flora
• insects
• insect pollination