With concerns about declines in pollinating bee species worldwide, there is renewed interest in solitary native bee species and their role in pollination services. We studied the foraging preferences and foraging distances of Lasioglossum sordidum (Halictidae), New Zealand’s smallest solitary bee, in urban Christchurch. Lasioglossum sordidum were abundant within the Christchurch Botanic Gardens. Pollen samples taken from 40 bees at each of two nest sites were identified using a pollen reference collection from the sites.
There are currently many attempts in New Zealand to restore native ecosystem functioning through the intensive control of introduced mammalian predators. One system that is faltering is bird pollination of endemic mistletoes (Peraxilla tetrapetala) by bellbirds (Anthornis melanura), apparently because of stoat (Mustela erminea) predation. We used a paired-catchment experiment in Nothofagus solandri var. cliffortioides forest at Craigieburn, central South Island, to measure whether stoat control could restore bellbird densities and mistletoe pollination.
Native birds may have been underestimated as pollinators of the New Zealand flora due to their early decline in abundance and diversity on the mainland. This paper reconsiders the relative importance of birds and insects as pollinators to eight native flowering plants, representing a range of pollination syndromes, on two offshore island refuges. Experimental manipulations were made on five of these plant species to assess the relative effectiveness of bird and insect visitors as pollinators.
New Zealand flowers are frequently considered unspecialised allowing easy access to pollen and nectar by a wide range of visitors. Most conform with a syndrome of insect pollination (entomophily). Pollination of forest flowers by birds has been described for a range of species whose flowers are morphologically ornithophilous. On Kapiti Island and Little Barrier Island, all three species of New Zealand honeyeaters have been described feeding on flowers currently assumed to be entomophilous or where the pollination system is unknown.
Dactylanthus taylorii, a root parasite in the family Balanophoraceae, is New Zealand's only fully parasitic flowering plant. It grows attached to the roots of a wide range of hardwood trees and shrubs, often in fire-induced secondary forest on the margin of podocarp-hardwood forest. It is inconstantly dioecious with a skewed sex ratio of approximately 5:1 male to female inflorescences. The inflorescences, especially the males, contain a large quantity of nectar, up to 1.6 mi, and can produce 0.5 mi per day for 10 days.
Recent concern that honey bees may threaten natural areas by increasing weed abundances through increased pollination was investigated by reviewing the literature to determine which weed taxa surveyed from New Zealand Protected Natural Areas (PNAs) are visited by honey bees. The contribution made by honey bees to weed reproduction was assessed by checking reproductive strategies and pollination mechanisms of a subset of problem weeds. A substantial proportion of surveyed weeds in PNAs are probably visited by honey bees (43%) including half of the problem weeds.
Thrips, in particular Thrips obscuratus, were collected from the flowers of 13 species of trees common in the lowland forest of New Zealand. Many New Zealand trees have flowers which are small, shallow, clustered, and lack bright colours. This un specialized floral form is suitable for pollination by small insects, such as flies and thrips. Thrips obscuratus is among the most frequent visitors to the flowers of some trees. The pollen loads of the thrips and the breeding system of the plants indicate thrips may function as effective pollinators.
Banana passionfruit (Passiflora tripartita var. mollissima) is an invasive vine in New Zealand where it lacks its natural hummingbird pollinator. We investigated the mating system and reproductive traits that facilitate its spread in the Marlborough Sounds. Flower observations revealed that visitors were almost exclusively introduced honeybees and bumblebees, indicating an invasive mutualism.
Worldwide declines in bird numbers have recently renewed interest in how well bird–plant mutualisms are functioning. In New Zealand, it has been argued that bird pollination was relatively unimportant and bird pollination failure was unlikely to threaten any New Zealand plants, whereas dispersal mutualisms were widespread and in some cases potentially at risk because of reliance on a single large frugivore, the kereru (Hemiphaga novaeseelandiae). Work since 1989, however, has changed that assessment.
Flower predators (florivores) may affect plant reproduction directly through loss of pollen and ovules, or indirectly by deterring pollinators which avoid damaged flowers. Caterpillars of the widespread endemic moth Zelleria maculata feed inside flower buds of the endemic mistletoes Peraxilla tetrapetala and P. colensoi in New Zealand. We measured flower predation rates between 1995 and 2007 at 24 sites throughout New Zealand and assessed Zelleria feeding impact on fruit set.