Beetle Mysteries

David R. Maddison

So far I have only one mystery here, but I'll add more later!

 Dinner plates on your mouth

Dyschirius aeneus

On muddy or sandy shores of rivers and lakes lives a small ground beetle called Dyschirius. There are many species of this genus. Some are very small (about 2 mm long), others are a bit bigger (over 6 mm long). They are odd-looking things, with a front (prothorax) that looks like a shiny ball, hinged onto a shiny, sausage-shaped back (mesothorax, methathorax, and abdomen). Most of them are black, but some are reddish brown, and others are black and yellowish. They like to eat other beetles (especially rove beetles).

Some of the oddest things about Dyschirius are their mouthparts. Females of Dyschirius have relatively normal palps (the little feelers they use while eating or while finding food), but males are odd. Their palps are swollen, with larger structures that look like dinner plates stuck onto their side. Here is a picture of the side of a palp of the female, and the side of a palp of the male:

Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window

On the left is a maxillary palp of a female Dyschirius, on the right of a male

It might be that these plates on the male are like tastebuds, allowing the beetle to taste things around it (perhaps whether a female Dyschirius it has found is of the same species!), or they might act more like suction cups. We just don't know: it's a mystery.

About This Page

David R. Maddison
Oregon State University

Page: Tree of Life Beetle Mysteries Authored by David R. Maddison. The TEXT of this page is licensed under the Creative Commons Attribution License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.

 Treehouses are authored by students, teachers, science enthusiasts, or professional scientists. Anyone can sign up as a treehouse contributor and share their knowledge and enthusiasm about organisms. Treehouse contributions are checked for general accuracy and quality by teachers and ToL editors, but they are not usually reviewed by expert scientists. If you spot an error, please get in touch with the author or the teacher. For more information about quality control of Tree of Life content, see Status of Tree of Life Pages.

close box

This page is a treehouse that is attached to a branch of the Tree of Life.

Treehouses are ToL pages designed for children and the young at heart.

For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.

close box


Treehouse Content

articles & notes




Explore Other Groups

random page

  go to the Tree of Life home page