Chalcid wasps are small

We relate to the world around us through our senses. We have little choice. There might exist a world of objective reality, the realm of Plato’s ideal, but we can’t reach it, except perhaps through pure mathematics (and even then, Plato says, we’re still looking at shadows on the cave wall rather than the actual objects that cast those shadows).

So, stuck in the cave as we are, we tend to judge the world around us as it relates to us. A slightly older contemporary of Plato’s, the ancient Greek sophist Protagoras summed up this anthropocentric tendency thousands of years ago in the pithy saying “Man is the measure of all things.”

This tendency has persisted to the present day, both in common usage and in cosmological theory¹ But we don’t need to be cosmologists to understand that we relate to the world around us through our human-sized senses. A pretty sunrise, for example, is easy to appreciate; it seems to be sized for our enjoyment:

The sun looks about as large as my thumbnail held at arm’s length—easy to handle, despite my knowledge of how incredibly large the actual sun is. The point I’m trying to make is that everyday experiences like these center around events, objects, and beings that are, or appear to be, in the human-sized world.

Our experience of worlds larger and smaller is less immediate. Both the microscopic world and the realm of the astronomically large are almost always mediated by our equipment: macro lenses,² to make the tiny objects that inhabit the micro world large enough to see, and telescopes, to magnify and make visible as extended objects the tiny points of light that are, in actuality, the largest objects in the universe: other planets, stars, nebulae, and galaxies.

That’s one reason I love these bits of optical gear so much. They open up realms of experience that are otherwise inaccessible to me. When I see a tiny little dot in the air with my naked eye, and it resolves itself into a lovely little bee through optical aid, I get a thrill. And when those tiny little dots and patterns in the night sky³ resolve themselves into recognizable patterns (for example, in Messier 42) in the eyepiece of my telescope, I get a thrill.⁴

Similarly, in our everyday experience of nature, be it in the back yard or at a nearby park (or even in a far-away national park or wildlife refuge), we tend to focus on those large objects that are visible to the naked eye: birds, butterflies, and perhaps the various shrubberies, trees, or flowers in which they appear. When we pay really close attention, we might see something as small as a dayflower, or a common honeybee or an ant, but that’s pushing our powers of observation to their limits:

To experience the true diversity of the natural world, at least as it manifests itself in the insect world, we need magnification. I use binoculars, a hand lens, or the macro lens on my camera. The camera lens is especially useful as it helps me record details that I’m unable to see in real time. (For example, it enabled an expert to identify that bee in the above picture.)

A recent fortuitous encounter through the camera lens drew my attention to the enormous wasp superfamily Chalcidoidea. This group is enormous in terms of diversity, not physical size: most of the over 22,000 described members are less than 3 mm from stem to stern; in fact, this group contains the smallest known insect, Dicopomorpha echmepterygis. And there are thought to be as many as 500,000 species in this group; there are so many of them, and they’re so tiny, that relatively little attention has been paid to them compared to the “charismatic megafauna” of the insect world like the beetles or the butterflies.

After several years of almost complete ignorance of their presence here in my yard I’ve recently discovered three tiny little members of this superfamily of wasps. At our current level of taxonomic sophistication, none of them can be identified to the species level, but they can all be assigned to a genus. Here they are, in alpha order:

Brachymeria species (family Chalcidinae):

 

Conura species (family Chalcidinae):

Eurytoma species (family Eurytomidae):

What’s astounding to me is how different all of these tiny creatures are from each other, once their images are enlarged enough to be useful. The conurid is eye-catching: bright yellow-orange body, with yellow eyes and black marks in distinctive patterns on the body; the two black wasps have remarkably different eye colors (bright red for the eurytomid, black for the brachymeriid) and antennal structure (the feathery antennae of the eurytomid differ markedly from the “straight” antennae of the two chalcidinids).⁵

While I know very little about these particular species, it seems plain to me that the conurid wasp is a predator, either a parasitoid or a hyperparasitoid; it’s constantly scanning the leaves of my wild lime bush for caterpillars. The other two wasps appear to be phytophagous, eating either the nectar or the pollen of the plants I find it on; they seem to adore my butterfly bush (Cordia globosa), and I frequently see them inside the flowers, rather than scanning, scanning, scanning for prey like the predatory wasps.

I’ve seen dozens of individuals of two of these species (the eurytomid and the conurid), which makes me think that they’re either gregarious or social, if not eusocial like the ants and the honeybees; so far I’ve only seen the one brachymeriid, so either it’s a solitary wasp or I’ve just not been paying enough attention. And part of the reason for this post is to testify that I haven’t been paying enough attention, and to try to remedy that situation.

But this is as far as I’ve gotten for now. Hope you enjoyed the trip!

References

Bug Guide. Available at http://bugguide.net

Noyes, J.S. Universal Chalcidoidea Database. Available at http://www.nhm.ac.uk/research-curation/research/projects/chalcidoids/

Wikipedia article on chalcids. Available at https://en.wikipedia.org/wiki/Chalcid_wasp

Related Images:

1. The anthropic principle in cosmology, for example, postulates that, in essence, the universe exists in order for us to contemplate it.
2. Nikon calls their macro lenses “micro” lenses, perhaps just as a branding technique, but perhaps also to make this distinction more obvious
3. At least, in areas where artificial light at night hasn’t washed them all out
4. Although to be honest, this thrill takes a bit more mental effort, involving my understanding of just what I’m looking at: when I realize just how far away that fuzzy blob named really is, and how truly massive it is, and how long it took the light from it to get here, it’s more of an intellectual and less of a visceral thrill than I get when, for example, I see a tiny insect right in front of me come into focus.
5. In case you’re wondering about all these names ending in -id, it’s pretty simple: for any taxonomic level above the species level, you can just add “-id” to the name to describe all members of that level, be it the genus level, family level, superfamily, subgenus, etc.