To be considered an effective pollinator, a floral visitor must not only be able to remove pollen but also transfer this pollen to a receptive conspecific stigma. While studies of diurnal pollination are commonplace, our understanding of the effectiveness of nocturnal pollinators is limited largely because of the difficulties of doing these studies at night. As a result of this, the way in which moths transfer pollen between flowers has been understudied globally, despite many authors suggesting they could be significant contributors to pollination.
On a global-scale, moths (Lepidoptera) are considered to be important pollinators for many plant families. However, the assumption that moths are also involved in pollination in New Zealand is underpinned by relatively little research. Here we review the evidence for moth pollination of flowering plants in New Zealand and compare the quality of evidence available with that of the global literature.
One of the strongest patterns in the historical record of biological control is that programmes targeted against lepidopteran pests have been far less successful than those targeted against homopteran pests. Despite fueling considerable interest in the theory of host–parasitoid interactions, biological control has few unifying principles and no theoretical basis for understanding the differential pattern of success against these two pest groups.
In New Zealand, the European shrub gorse (Ulex europaeus) is becoming the initial post-disturbance shrub, replacing the native myrtaceous manuka (Leptospermum scoparium) and kanuka (Kunzea ericoides) scrub in this role. Change in the dominant vegetation is likely to affect the native invertebrate community.
Two of New Zealand's most important insect pests, grass grub and porina, are endemic species which have successfully colonised improved pastures. Population densities of these insects within this new environment are far greater than in the native plant systems in which they evolved. Within these high populations diseases have flourished, and high numbers of diseases are recorded from each of these pests. These include bacteria, fungi, nematodes, viruses and protozoa.
Species-rich moth faunas at two sites in a montane tussock grassland at Cass show major declines in the abundance of many common species between 1961-63 and 1987-89, furthering a 50- to 70-year trend. The recent faunal record (202 species) is quantified by a 3-point light-trapping methodology based on independence of serial samples, minimised sample variability and a posteriori data standardisation. An historical record of vegetation change is also presented, pointing to a major decline in endemic herb species with the advances of an adventive grass, Agrostis capillaris.