ON ‘THE SIXTH EXTINCTION’

(SEPTEMBER/OCTOBER)

Although I applaud the inclusion of the article summarizing the sixth extinction, there were two serious omissions regarding the extent and impact of the human assault on our planet’s ecosystems. Although mentioned in passing, it is the insects that are the movers and shakers of all terrestrial ecosystems. Presently there are about 1.9 million named species of metazoan (multicellular) cataloged, with at least 40 per cent being insects. However, vast numbers of insects remain undescribed and unnamed. A detailed taxonomic study in a tropical habitat, spearheaded by colleague Brian Brown and me, showed that there were more than 4,332 species of flies occurring in just four hectares of cloud forest in Costa Rica. Most were unnamed. When one sees clear-cut mountains in tropical countries, one should realize that many thousands of insect species are already extinct before they could even be studied. The information in the article was largely based on vertebrates, certainly because that is where the best data are. So why are insects not central to concerns about extinction? In large measure, it is because of our ignorance of what is out there. An army of insect taxonomists is needed to study what is left of our world’s biodiversity. Tropical countries have little hope of interpreting and protecting much of their disappearing fauna and flora without substantial assistance. It is to our collective loss and that of all future generations.