Category Archives: Myrmecophiles

Masoncus-season #2 begins

About a year ago I blogged about how I had started collecting a species of linyphiid spider with Formica ants that nest in my front yard. I left the post open ended, hoping that someone would have an idea of what the spider species might have been. I was picking up multiple life stages, both sexes and had accumulated over 40 specimens over the course of the field season. Given these statistics, it was hard for me to believe that these spiders were accidentally occurring with ants and became convinced these spiders were myrmecophilous.

A mature female Masoncus sp. wanders among its hosts.

At the time little did I know that I was to receive an email informing me that the spider may belong to the genus Masoncus and was directed to the research of Paula Cushing. She worked with a, at the time, new species of Masoncus that occurred with Pogonomyrmex in southeastern USA. Observations revealed that these spiders follow host trail pheromones to accompany host nest site switches. I contacted Paula and we believe that the species in my yard might be a new species, which had also been collected recently in Wisconsin.

Masoncus sp.

A mature female Masoncus sp.

Masoncus sp.

A mature female Masoncus sp.

Several of us are now working together to further understand the biology of Masoncus in relation to its hosts. As a part of this objective, we are currently accumulating material for gas chromatography-mass spectrometry (GC-MS) to compare guest and host cuticular hydrocarbon profiles (CHC). These spiders wander the nests freely, undetected, and may be acquiring CHCs from their hosts either passively or actively, essentially camouflaging themselves among the ants. On the flip side, these spiders may just “have no smell.” These are both commonly employed strategies to infiltrate ant colonies among arthropods. Either way, the GC-MS should tell us more.

More minis.

TA meeting, applied for money, reviewed a manuscript… Before I continue on with more pressing tasks, here are a couple more mini-clavs. These are from the KU collections.



And, something to stimulate your auditory senses while these little guys blow your visual fuse box.

Oh, and next time your lab gets dry ice.

Who likes ant-guests? I like ant-guests!!

As a reader of my blog, you’re probably already aware of symbioses with social insect. What does this mean? Well, social insects (think ants, termites, bees, etc.), just like our societies, can become infested with freeloaders – basically, pests – we have rats and ants have beetles that also scavenge on leftovers.

Some object, but I think that drawing analogies between economics and evolutionary theory can be a fun and insightful exercise, so here I go: In economics, there is this idea that the number of loopholes (e.g. number of ways to cheat your taxes) in a system increases with complexity.

In other words, the more complex the social system, the more ways to cheat the system. This phenomenon seems to be mirrored in the societies of social insects – the more complex the sociality, the more ways, and therefore, the diversity of  freeloaders in the nest increases. (If you haven’t already, please check out Joe and my blog post over at Scientific American.)

Once you’ve decoded the social system of your host(s), it’s a pretty easy ride: air-conditioned accommodation, an extreme concentration of energy, and protection from enemies. But scientists have been struggling to figure out just how you get to a point where you are truly integrated in the host’s societies.

Rove beetles have left all other insects in the dust when it comes to symbiosis with social insects. In particular, the Aleocharinae and Pselaphinae stand out as “evolutionary success stories.” Interestingly, the two groups couldn’t look more different. Aleocharinae are elongate and flimsy (my specialty), while the Pselaphinae are compactly formed tanks of a beetle (Joe’s specialty). This might mean two things: 1) the Aleocharinae retain abdominal flexibility which can allow for gross morphological redesign in contrast to the Pselaphinae, which seem to have given up that option; 2) the Pselaphinae are tanks, their tough, and a few attacks from a host aren’t going to be detrimental – a stark contrast to a flimsy Aleocharinae.

Myrmecoid (hey, that's the name of the blog!) Aleocharinae: independent examples of drastic abdominal modification.

Myrmecoid (hey, that’s the name of the blog!) Aleocharinae: independent examples of drastic abdominal modification.

What does that mean? Well, it seems that Pselaphinae, although they’ve given up the ability to drastically rearrange their abdominal morphology as an adaptive strategy for living with social insect colonies, have bought themselves a different entry pass into the nests of ants and termites. Again, Pselaphinae are tough. As long as they can withstand a few attacks here and there, given some time in the nest, adaptations present or not, you’ll start to pick up host colony odors.

Nest-mate recognition in social insects appear to depend heavily on “colony odors” in the form of unique cuticular hydrocarbon profiles. These hydrocarbons, like all compounds, express some amount of volatility ~ kinda like smelling like Indian food after you’ve left the place. You take this a step further and you can imagine the evolution of structures and/or behaviors that optimize ability to pick up host colony smells, and become, for all intents and purposes, invisible to those around you. Toughness, in evolutionary time might prove to be one of a few options for entering into social insect symbiosis.

Blah, blah, blah; sorry, I know that was long up to now, but I really wanted to set the stage so that YOU, the reader, can truly appreciate the videos that follow.

Why? Well I’ll let this quote from a Senegalese conservationist, Baba Dioum give it to you straight.

In the end, we will conserve only what we love, we will love only what we understand, we will understand only what we are taught.

And I hope that we can preserve these evolutionary miracles for the future – because they are so awesome!

The following videos were taken and sent to me by my friend, colleague and developmental/evolutionary biologist extraordinaire Joseph Parker at Columbia U., which got us discussing their amazingness and we couldn’t resist sharing. Videos today concern two stars form the Pselaphinae: Harmophorus and Batraxis. The two genera are both faculitative symbionts, although Batraxis seems to have inched a little closer to an obligation to its myrmecophilous way of life. In addition, Batraxis seems to be “invisible” to their host ant while Harmophorus is not entirely so – possibly corroborating my previous statement.

Harmophorus with its usual host (above). The ants are aware of Harmophorus‘ presence and attack here and there, but thanks to the beetle’s hard exterior and compact body, very little, if not any damage seems to have been inflicted.

Batraxis and its natural host (above). Notice that the ants don’t even seem to realize their presence.

Look what happens when we switch the host ants between Batraxis and Harmophorus. While Batraxis (above) walks around unmolested by their novel host, Harmophorus (bottom) is being absolutely pummeled. Although, again, thanks to the Harmophorus‘ robust nature, seems to be OK despite the many bites and stings.

For Joe and I, this was a p-scientific way of demonstrating the possibility of an ecological transitional series from free-living to social insect symbiosis. Can’t you imagine a beetle like Harmophorus, beginning to demonstrate a propensity to live with ants, → evolving some better strategies for colonial integration (e.g. Batraxis), → until “perfecting” the art as the clavigerines have.

Difficult to test, definitely. We’ll need observational, phylogenetic and experimental data in order to begin to weave a supported story. But, the evolutionary magnificent these organisms display! I would gladly give my life studying them, even if it means merely discovering the corner pieces to a puzzle for which its dimensions remain a mystery.

Snowed in

School’s closed again. I had to blaze a trail to lab today. I’ll use my tracks to go home.

A small clavegerine that Joe and I plan to describe. We think it might be a new genus. This particular species is Brazilian and from the British Museum. We have another two species from the collections here at KU.

A tiny myrmecophile.

A tiny myrmecophile.

Clavegerines are a diverse lineage of myrmecophilous pselaphines. They have compact appendages, especially those antennae. Some observations have elucidated, they twirl the those nubby antennae when they’re trying to assess the situation within their ant-nest homes. “Hmm, what’s going on?” (twirl-twirl)

Save science at the Field Museum

The Field Museum has been feeling the economy for some time, but now the president is proposing to scale back research at the Field in order to survive the economic downfall of the institution.

Please, please consider signing this petition and please, please consider spreading the word.

New Publication

Thanks to everyone that accessed/shared Joe and my guest blog yesterday!

In our blog article, Joe and I touched on the immense subject of myrmecophily. Hopefully we got across the message that this ecology has evolved many many times in staphylinids. This naturally means that the funky-looking mymrecophile morphologies ultimately are derived from normal-looking precursor ancestors.

Here’s a new pub of mine titled: Redescritpion of the genus Apalonia Casey, description of immature stages and reevaluation of its tribal placement.


Apalonia up to now had been considered to be a constituent of the tribe Lomechusini, a group that is comprised mostly of myrmecophilous species. It turns out, though, that most New World taxa traditionally considered to be Lomechusini belong to a different group.

Basically, past researchers were fooled by convergent morphologies that are apparently adaptive for myrmecophily.

In this paper, I use evidence from larval and adult morphological characters to transfer Apalonia out of Lomechusini. Apalonia are not myrmecophilous but fungus-feeding, similar to its close relative Meronera.

Guest blogging at Sci.Am.

Recently Joe Parker invited me to join a guest blog post at Scientific American, the topic being non other than… myrmecophiiles!

Diartiger fossulatus, a consummate obliggate myrmecophile. One of many stars in our new guest blog post over at Scientific American.

Diartiger fossulatus, a consummate obligate myrmecophile. One of many stars in our new guest blog post over at Scientific American.

The post just came out today! Please check it out, spread the good word, and help give these beetles the opportunity to prove themselves under the limelight.

Please enjoy the post with a little Digable Planets on this pleasant Monday morning.