More than 40 new beetle species discovered in Tahiti

Scientists have discovered more than 40 new beetle species in the island of Tahiti in French Polynesia.
A group of entomologists recently embarked on a month-long survey to update Tahiti's species classification records, and returned with 600 ground-dwelling beetles - those that have lost their flight wings through evolution.
The collection included more than 40 new species, 28 of which are described for the first time in the journal ZooKeys.
Ground-dwelling beetles are small - measuring between 0.1 to 0.3 inches long - and can be difficult to see on a shaded forest floor, 'LiveScience' reported.
To collect them, the team sprayed foliage near the ground with an organic chemical that causes insects to become more active, and crawl out from under hiding places in leaves and ferns. The team then laid down a white nylon sheet where the insects gathered.

After the expedition, Jim Liebherr, an entomologist at Cornell University who led the beetle component of the expedition travelled to the Paris Natural History Museum to compare his specimens with the largest collection of Tahitian ground-dwelling beetles worldwide.

Aside from looking for obvious differences in the exterior shape of the body and the distribution of hairs, he also dissected and compared genitals - often a distinct indicator of beetle species - to figure out which of his beetles represented new species.
Tahiti's insect diversity results, in part, from its jagged terrain, which keeps insect populations separate by preventing them from mating.

The island also has large patches of unstable soil, which easily become dislodged and fall away with rain forest rainstorms, contributing to the fragmenting and isolating of insect populations that eventually evolve into distinct species.