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Little Transformers: Eburia pedestris

We are back to celebrate little transformers: insects that are more than meets the eye. In this post I feature an insect whose transformation may seem a little awkward at first. It is not of cryptic nature, and it is not a case of mimicry.

While doing research about whip spiders in Belize, I also surveyed the insect biodiversity of one site, and so made sure to visit the light traps that we set up in several spots. The traps attracted an impressive diversity of insects, including moths, leafhoppers, ants, mantids, and katydids. One night a beautiful longhorn beetle (family Cerambycidae) showed up at the light trap. I did not recognize it at first so I collected it for a short Meet Your Neighbours session.

Longhorn beetle (Eburia pedestris) from Belize

Longhorn beetle (Eburia pedestris) from Belize

It was Eburia pedestris, a member in a genus of hardwood-boring longhorn beetles with a wide distribution in the Americas. I took a few decent shots. The beetle was trying to escape of course, so I reached out to grab it before it fell from the acrylic sheet. The moment I touched it something interesting happened. It crossed its legs and took a sitting position. I could not help it and I sneaked a loud laugh, because it looked like the beetle was in the middle of a yoga practice. It stayed in this comical position for a while, so I took some additional shots.

Longhorn beetle (Eburia pedestris) just sitting around

Longhorn beetle (Eburia pedestris) just sitting around

Another view of the strange pose taken by Eburia pedestris

Another view of the strange pose taken by Eburia pedestris

The strange position did not make a lot of sense to me, but I thought maybe it was a more elaborate way of playing dead, a common behavior in many beetle families (which will probably be featured more than once in this series). I finally decided not to wait for the cerambycid to “open up” so I grabbed it in my hand to put it back into the vial before releasing it outside. And then it hit me.

I mean, it literally hit me.
I felt my hand being pierced in several spots. Blood was dripping from my fingers.
You see, there is a reason why Eburia beetles take this unusual body posture. Look at the beetle’s leg joints and at the tips of the elytra. By taking a “sitting” pose, the beetle transforms into a prickly business, pointing sharp spikes in all directions, making it difficult for large predators like myself to handle the beetle. It will also not hesitate to use its other cold weapon: biting mandibles. Something I only noticed much later when I examined the photos – notice how the beetle contracts its abdomen, to make the elytral spines more prominent. Even with caution it was difficult not to get your skin punctured by the spines. They are as sharp as syringes. I would not want to imagine the experience for a mammal trying to eat this beetle. Ouch.

Longhorn beetle (Eburia pedestris) in defense posture. Grab it if you can.

Longhorn beetle (Eburia pedestris) in defense posture. Grab it if you can.

Some insects prove to us that avoiding predators is not all about hiding, mimicking other organisms, and advertising toxicity or potent venom. There are other, more creative ways to survive in the jungle out there. I will even take it a step further and say this Eburia beetle is comparable to the armadillo girdled lizard in its behavior. Nature is so awesome.

Don’t mess with the Huhu

On my first night in New Zealand, I did something that I always do when I get to a new place – see which insects were attracted to light that was left on. The usual suspects are various species of moths, but sometimes also katydids, antlions and beetles.

To my surprise, the first insect that I found was a large longhorn beetle (family Cerambycidae). With a length of 50mm, hairy body, large mandibles and beautiful elytra reticulated in yellow, one could not miss it resting on the asphalt. I later learned that this was the huhu beetle, Prionoplus reticularis, New Zealand’s largest endemic beetle.

The huhu beetle, Prionoplus reticularis

The huhu beetle, Prionoplus reticularis

Detail of Prionoplus reticularis elytra

Detail of Prionoplus reticularis elytra

 

Portrait of Prionoplus reticularis

Portrait of Prionoplus reticularis

 

The adult huhu beetles do not feed and live for about two weeks only. These insects spend most of their lives in the larval stage, boring into and feeding of dead wood. They can become pests in sawn timber and logs, eventually destroying the wood and leaving just the outer shell. The larvae are considered delectable wild food and were traditionally harvested by the Māori people to be eaten raw or cooked (note to self: I need to try this). At the end of their growth the larvae reach an impressive body length of 70mm and create a chamber for pupation. The adult beetle emerges from the pupa after 25 days and uses its strong mandibles to break free from the pupation chamber in the wood. The whole life cycle can take up to several years.

The adult beetles appear during the southern hemisphere spring and summer (November to March). They start their activity around dusk, and many of them reach outdoor lights and well-lit rooms in their heavy flight. I often found mating pairs in close proximity to light bulbs.

 

Many people fear these beetles for no good reason (or worse – I heard people relate to these beetles as cockroaches). The adults look a bit scary with their enormous jaws and long antennae swinging from side to side as they walk, but they are harmless and not aggressive. Well, that is, if they are not provoked. They can still use their mandibles to bite, but their bite is a lot less serious that other bites I got while in NZ (for example, ground weta’s. Stay tuned!).

 

Huhu beetle (Prionoplus reticularis). He's coming to getcha!

Huhu beetle (Prionoplus reticularis). He’s coming to getcha!