Bug-Catching: It Ain’t Easy

National Geographic grantee Nik Tatarnic is taking a closer look at the traumatic sex lives of Tahiti’s tiny bugs. Follow Nik’s expedition on Explorers Journal as he investigates the bizarre sexuality of the genus known as Coridromius.


Well, it’s been 10 days in Tahiti and things have been pretty hectic. We’ve circumnavigated the island several times, ascended a few mountains, climbed several trees, fallen in the mud, been attacked by hornets, and searched through just about every piece of vegetation on the island for our bugs. We had plenty of strike outs, but also a few hits. Here’s a brief snapshot of our journey so far.

1) Getting around the island. There’s essentially one main road around Tahiti. On the plus side, it’s pretty hard to get lost, but on the minus side, it’s near impossible to access the forested, mountainous interior. We’ve teamed up with Dr. Jean-Yves Meyer, local botanist/naturalist/explorer, who knows the island like the back of his hand. With Jean-Yves’ help, we’ve managed to drag ourselves up to almost 2,000 meters above sea level on a few of Tahiti’s highest peaks, all in the hunt for our little bugs.

Jean-Yves tries to unstick his 4X4
Jean-Yves tries to unstick his 4X4. Photo courtesy of Nik Tatarnic.

2) How we catch our bugs. Given the tiny stature of our study insects, you can’t just walk up to a plant and pick them off the flowers. Instead, we use a collecting method called “beating”. The technique is pretty simple – essentially, we take a stick and hit the leaves and flowers of a plant, dislodging the unsuspecting insects and knocking them into an awaiting net below. These are then sucked up into a collecting jar using an aspirator. Sounds simple, right? Well try doing this on a rainy mountain ridge trail 1,500 meters up, or while hanging in a harness from a tree (on said ridge). On top of that, the bugs have massive jumping hind legs and bounce around like nobody’s business, so they often escape before we get a chance to suck them up. It ain’t easy.

Hunting insects in the canopy along the trail to Mount Aorai
Hunting insects in the canopy along the trail to Mount Aorai. Photo courtesy of Nik Tatarnic.
Luke and Nik hunting bugs on Mt Marau. Photo courtesy of Nik Tatarnic.

3) Observing bug behavior. No matter how you slice it, this part of the job is tough. The bugs are small and fast, and they don’t always cooperate. Since we’re trying to document mating behavior, there are a few things we can do to help set the mood and increase our odds. The first thing we do after collecting a whole bunch of bugs is determine the sex and species of each individual. (Since we think one species is mimicking the other, the latter process can be pretty tricky.) Once the bugs are separated, we give each one some host plant and leave them overnight. By the next morning, hopefully they’re eager to mate.

Like I said, these bugs move fast, so we can’t always rely on being able to see what’s going on the first time around. To overcome this, we film each interaction so we can go over it later frame by frame. This is done with an HD camcorder on a tripod, outfitted with a 5x magnification diopter lens. Then, using a technique I learned from a documentary filmmaker, we place the bugs in a cage made from two panes of glass separated by about 1 cm (in our case we used a pair of picture frames sandwiched together). In this manner the bugs can move about in two directions, but cannot move too far in the third, thereby staying within the limited depth of field of the camera.

A pair of Coridromius tahitiensis about to mate
A pair of Coridromius tahitiensis about to mate. Photo courtesy of Nik Tatarnic.

We still have a week left of exploring, collecting, and experiments. With a little luck the weather and the bugs will co-operate. I’ll let you know how we go in a few days!

NEXTHow to Find a Bug the Size of a Grain of Rice in Tahiti’s Dense Tropics

Changing Planet


Meet the Author
I am a biologist specializing in the evolution, ecology and behaviour of insects. I am particularly interested in the role of sex in evolution - how sexual selection can drive changes in morphology and behaviour, ultimately leading to speciation. Born in Canada, I am currently living in Australia, where I am Curator of Entomology at the Western Australian Museum.