for National Geographic News
The term "endangered species" typically conjures up images of charismatic animalstigers, pandas, orangutans, whales, condors. But a new study says that the vast majority of species on the verge of extinction is in fact humble insects.
The study estimates that up to 44,000 bugs of all varieties could have been wiped off the face of the Earth during the last 600 years. And hundreds of thousands more insect species could be lost over the next 50 years.
Only about 70 insect extinctions have been documented since the 15th century, possibly because many insects have been poorly studied.
"Most extinctions estimated to have occurred in the historical past, or predicted to occur in the future, are of insects," argues entomologist Robert R. Dunn of North Carolina State University in Raleigh.
The finding is significant, because insects play vital roles in plant pollination, decomposition, and soil processing. They also form essential links in ecological chains as plant-eaters, predators, and parasites.
The loss of keystone insect speciesthose on which a large number of other species dependcould be especially detrimental for ecosystems and people.
Multitude of Missing Species
"Most entomologists I know have some species they haven't seen in years, but [they don't] have the time or money to look for them," said Dunn, who reports his findings in the current issue of the journal Conservation Biology.
"It wouldn't be hard to come up with a list, for example, of 50 ant species in the Americas that haven't been seen for 50 yearsmany in urban areas that used to be wild," he said.
Insects make up 80 percent of all known animal species. Though only 900,000 insects have been identified, experts agree that there are still vast numbers of undocumented species. Estimates vary, but some researchers believe that as many as 2 to 100 million insect species could exist.
To estimate how many insects may have become extinct in recent history, Dunn first looked at figures for well-documented birds and mammals. He found that, over the last 600 years, 129 bird species have gone extinct, or 1.3 percent of all existing bird species.
Dunn then assumed that 3.4 million insect species live on Earth. If insects go extinct at a similar rate as birds do, then about 44,000 species could have disappeared over the same time period.
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