Second Largest Insect Ever Discovered at Two Feet Long

It's official: the second largest bug in the known world is one very long twig... or more accurately, an incredibly large stick bug.

Also known as "walking sticks" (not to be confused with the hiking equipment), stick bugs are a type of leaf-eating insect that rely on their unique and incredibly convincing form of camouflage. Their long segmented bodies, legs, and even antennae all look exactly like long discarded twigs.

This makes them difficult animals to study, as this camouflage makes them tricky enough to find. Add in the fact that they are unlikely to move until after night falls, and entomologists find themselves looking for a needle in a stack of needle-like hay, in the dark. Talk about a challenge!

However, for decades exceptionally patient experts have been up to the task, identifying a whopping 3,000 species of the Phasmiatodea order. Some of these bugs resemble stumps, leaves, and even thorns rather than sticks, but the twig-like form is the most common. The Phobaeticus kirbyi of Borneo was thought to be the largest of these bugs, with its females measuring just over a foot long. This made it one of the longest insects in the world.

However, the recent discovery of the Phryganistria heusii yentuensis subspecies, as described in the journal European Journal of Taxonomy, may be knocking other ruler-sized bugs down a few pedestals.

That's because the discovery, made in Tay Yen Tu Nature Reserve of Northeastern Vietnam, is nearly two feet long, at 21 inches (54 cm), earning it the title of the second longest insect ever recorded. The world record holder, of course, is another stick bug known as "Chan's Megastick."

As described in the study, a research team from the Royal Belgian Institute of Natural Sciences (RBINS) identified three new taxa of stick bug in all, after surveying various preserves and parks in Vietnam and China. (Scroll to read on...)

For the most part, the researchers used a very hands-on method to find these insects: laying a sheet on the ground and vigorously shaking nearby trees and bushes. However, when they found their giant, it was just calmly crawling along a nearby bush.

When speaking with Wired, they admitted that some very choice words were exclaimed with the initial discovery. After all, it's a bit startling to see a nearby branch just pick up and start walking on its own - even if that's exactly what you were looking for.

The researchers told DeRedactie (Dutch Language) that even after they knew what they were looking for, they still had a hard time finding multiple examples of the massive insects.

"They are almost only active at night and they make with their elongated body and green-brown color in shrubs and trees almost invisible," said Jérôme Constant, an entomologist at the Institute.

"We found that the color of males does not vary, but females do," added researcher Joachim Bresseel, who explained that this complicated things. Females, being the largest, would normally be easier to find, but with several potential colorations they had more potential hiding spots.

Thankfully, the bugs helped in their own unique way: by hooking up. Entomologists have long known that stick bugs copulate very slowly, often taking days to get the deed done. Males have even been known to hang around for longer, hoping to essentially "cock block" the competition. If two sticks that happen to be of a different hue get together, they become easier to spot for some time.

Even still, "it often took up to two hours at night before we returned to base camp with the collected specimens," Constant said.

The team is now reportedly working in cooperation with Vietnamese biologists to help build a reference museum collection, even as they develop keys to help identify these stunning insects.

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).