This article was prepared by postgraduate student Olga Petko as part of the ECOL 608 Research Methods in Ecology course.
When we hear the word “biodiversity” magnificent tigers and cute koalas, beautiful coral fish and bright parrots first come to mind. But biological diversity or, to be more precise, species richness, is not about appearance or popularity but is simply about numbers. And no other group can claim to be richer in species than the insects.
Insects can be found almost anywhere: running on sand in hot deserts or making tunnels inside icebergs, flying over tropical forest canopy or hiding behind curtains in your room. Any habitat is a home to countless six-legged dwellers, one just need to look. Little wonder that mushrooms are not an exception. To look at fungi of New Zealand to find out who exactly finds them irresistible is an adventure on its own for such a dedicated entomologist as John Marris from Lincoln University.
The woodland insects associated with the fruiting bodies of macrofungi, i.e. mushrooms, include specialist fungi-eaters, generalist detritus feeders and all their associated predators and parasitoids. Marris and his colleagues used rotted commercial mushrooms (Agaricus spp) as a bait to collect insects from native beech forest (Nothofagus spp), native mixed forest, exotic conifers (Pinus radiate or Cupressus macrocarpa) and urban restoration areas. Overal 2 429 invertabrates were collected, which mainly consisted of beetles (Coleoptera), flies and midges (Diptera), also parasitic wasps (Hymenoptera). To name just a few interesting species: a parasitoid wasp of spider eggs Idris spp (Baeini), round fungus beetles Leiodidae, Saphobius spp (Scarabaidae) and moth flies Psychoda spp (Psyhodidae). Of course, as it always happens with these tiny creatures, among collected specimens were several newly-described genera and new species.
The list of insect species that are associated with mushrooms increases our knowledge of the nature of New Zealand. Worldwide habitat-specific insect assemblages are used as indicators of site quality and conservation value, as well as measurement of anthropogenic disturbance. The survey of Marris and his colleagues showed that two conspicuous native beetles Zeanecrophilus prolongatus and Saphobius can be used as good indicators of site quality. A handy method in assessing the remnant patches of New Zealand woodland. It also became clear that monoculture plantations of exotic conifers are not a wood equivalent of a desert and can compare favorably to native forests in terms of richness and diversity of insect faunas. What is most important these plantations can provide suitable habitat for indigenous insects too.
There are many restoration projects in cities and around them. And here is the good news. The research brought new evidence that despite the fact that urban nature reserves are small in comparison to remaining native forest and low in total species richness, they still play a valuable role in conservation of invertebrates, providing a refuge at a local level.
This study was first of its kind in New Zealand. The “mushroom bait” method is not ideal, not all insects are attracted by the smell of commercial Agaricus. The researchers are sure that the use of any native New Zealand fungi as bait or alternative collection techniques will widen the species list of the citizens of Mushroom City.