Posted by Theo Van Noort @TVanNoort
All manner of pollination interactions exist, from the simple to the bizarre, even downright exploitative, involving plants and animals of all growths, walks and flights of life (disclaimer: I don’t know of any fish that carry pollen, but apparently they can influence pollination interactions…).
Broadly speaking, New Zealand’s plants have simple flower morphology, with flowers generally being small, white and attractive to a wide suite of potential flower visitors.
New Zealand has no native social bees or wasps, so these unspecialised native plants rely heavily on solitary insects, particularly native bees (check out this previous blog by Anna) as well as flower visiting flies, moths, butterflies and beetles to provide pollination services. Native plants with more specialised pollinator interactions also exist, particularly involving native birds, but bats and even lizards have played a role in the evolution of New Zealand’s flowering flora too.
Introduced organisms can integrate with existing pollination networks and may augment them with some degree of resilience to the ongoing native biodiversity loss. A classic example of this is the European honeybee.However, the impact of new organisms in a pollinator network can be unpredictable. An introduced flower visitor might not provide adequate pollination to a flowering plant but nonetheless remove nectar, “robbing” the plant of its ability to lure in other effective pollinators.
Of course the opposite may be true, where a new flower visitor may be rather effective at pollinating a certain plant. This latter interaction can be concerning from a biosecurity point of view when it results in “facultative mutualisms” between invasive plants and introduced flower visitors- improving the ability of each to succeed in and further disrupt ecosystems. This is demonstrated in the interaction between the invasive plant scotch broom and honeybees here.
My Masters thesis is focused on the ecology of Vespula wasps (here’s my previous blog). As part of my work I’ve been exploring the behaviour and role of these aggressive insects in pollination networks in New Zealand. Sugar resources are known to enormously influence the ecology of Vespula wasps, as seen in honeydew beech forests in the South Island, so it is interesting to consider how another ubiquitous (albeit less abundant) sugar source, nectar, may also be influencing their behaviour and ecology. While I’m still making sense of the data, one major outcome is that I spend much more time stopping to sniff the flowers (and check out any other flower visitors that might have stopped by!)
Theo Van Noort is an MSc student in the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland. He is investigating the attractiveness of different lures to Vespula wasps, as well as their potential role in pollination and seed dispersal. He is supervised by Jacqueline Beggs and Imogen Bassett