Most Wasps Are Misunderstood…
‘Wasps’ are truly a diverse group of insects – with over 100,000 species known out of an estimated total of 350,000, they make up a considerable chunk of biodiversity.
It’s true that some wasps wreak havoc against native biodiversity and cause serious allergic reactions when they turn their sights on people. However, only a handful of species give wasps their bad reputation in New Zealand:
- Common wasp (Vespula vulgaris)
- German wasp (Vespula germanica)
- Asian paper wasp (Polistes chinensis)
- Tasmanian paper wasp (Polistes humilis)
- European paper wasp (Polistes dominula)
These five introduced species have tarnished the reputation of New Zealand’s misunderstood wasps.
We have up to 3,000 native wasp species (compared to about 250 native birds), and none of our natives are social wasps. This means they don’t form colonies and won’t sting, preferring instead to lead solitary lives as ‘parasitoid’ wasps.
Parasitoids can be thought of as being intermediate between predators and parasites. Like parasites, they require a ‘host’ to feed on to complete their life cycle. But unlike parasites, they eventually kill their host. In parasitoid wasps, females inject their egg into the caterpillar of another insect (or lay it on the outside of the caterpillars’ body). The wasp larvae that hatch out feed on the bodies of their hosts, slowly draining away their vitality, and using this nourishment to develop into adult wasps.
Parasitoids play important roles in the ecosystems they inhabit. By keeping a lid on their host populations, parasitoids ensure that no single group gets too abundant. This means that parasitoids help to ensure the diversity and abundance of other organisms is maintained. They make up a staggering portion of global biodiversity, so being ignorant of them makes us ignorant of much of the animal life on the planet. Naming, describing, and studying the distributions of parasitoid species makes significant contributions to our overall catalogue of life.
Not only are parasitoids found almost everywhere, they are also involved in a myriad of interactions with their hosts, the plants their hosts feed on, and the wider web of organisms within those areas. If we are to conserve species or habitats, we need to know how they work, which means understanding the complex networks that parasitoid wasps are a part of. Humans can also harness the behaviour of parasitoids in ways that benefit us. We can introduce them outside their native ranges to control pests (after careful testing), and we can potentially use them to monitor the ‘health’ of an ecosystem. However, parasitoids exhibit attributes that make them extinction prone: they rely on unpredictable resources (their host populations may fluctuate wildy); they are present in naturally low numbers; and they have very high levels of endemism (i.e there are many species that are found no where else in the world).
Therefore, I believe their study should be prioritized by conservationists, the primary industries, and the public in general.