Tropical Insect Populations Crashing?

Early in the 1980s, a scientist named Terry Erwin decided to count the number of Coleoptera species — the insect order containing beetles and weevils — in the rainforest canopy. He was trying to answer a really big question: how many species live on Earth? And he figured beetles, one of the planet’s super-families, was the place to start.

So he packed of…