Category Archives: Myrmecophiles

Blapstinus, not welcome

Pogonomyrmex harvester ants dump scraps outside their nests.

Pogos at night.

Pogos at night.

For scavengers, this can be a lucrative place to visit for a meal. Tenebrionidae are frequent visitors. During our trip to TX this past summer, Blapstinus were very diverse and abundant around Pogonomyrmex nest entrances at night.

Blapstinus just eat trash so they’re a benign existence, but nonetheless are not welcome in the eyes of the ants.

This Blapstinus is not welcome.

This Blapstinus is not welcome.

Myrmecophily is a spectrum

Sometimes in the literature I come across definitions of myrmecophily that are quite restrictive, limiting the phenomenon to the most integrated members of the niche. I strongly think that myrmecophily is a spectrum, ranging into those that are more loosely associated with ants. If we don’t consider the entire spectrum, we miss the entirety of an ecosystem centered around an ant society.

From Texas again. This is Araeoschizus, a tenebrionid. These guys are loosely associated with ants, but they seem to have a tendency to be found with them. I often collect them with a variety of ant species. This trip, I observed them actively following Solenopsis (?) foraging columns at night for the first time. This adds to the complexity of Araeoschizus natural history.

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This one from Monahans Sand Dunes

This one’s from Monahans Sand Dunes

In situ Pella is the best kind of Pella

Finally got it! Evidence of Pella planifer behaving in its natural environment.

Pella planifer investigating the vicinity of Crematogaster activity.

Pella planifer investigating the vicinity of Crematogaster activity.

We know from work conducted in the Palearctic that species of Pella hang around the nest vicinities of their host ants, preying upon weakened workers and scavenging on whatever opportunities that may arise. But these observations were geographically limited and the few Pella species of North America were a behavioral enigmas.

Based on my own previous observations, it had been becoming clear that North American Pella exhibit similar behaviors and ecologies as their Old World cousins. That’s all dandy but there is nothing that can top visual evidence to support an organism’s behavior in its native environment – today, I’ve finally accomplished this.

Pella planifer biting and tugging at a Crematogaster queen in midst of colony recruitment.

Pella planifer biting and tugging at a Crematogaster queen in midst of colony recruitment.

Crematogaster wake for spring

There’s a Crematogaster colony that lives in my backyard where I’ve periodically searched for Pella planifer. I also use the colony’s activity as a proxy for ant activity. Before I set out to go collecting, I frequently check the activity of ants in my yard in order to assess how the collecting that day is going to be.

Ants active? Great, I’ll check foraging trail periphery for Pella today.

Ants not active cause it’s too hot? Too bad, maybe I’ll put off myrmecophile collecting until fall.

It wasn’t until around 1 PM that the Crematogaster began to forage, a little chilly today. Nonetheless, decided to check out the column for Pella later in the afternoon, hoping to snap some in situ action shots of Pella destroying Crematogaster workers.

For a second there I saw a scuttle out of the corner of my eye - not Pella but a free-living athetine of some sort. Maybe Acrotona?

For a second there I saw a scuttle out of the corner of my eye – not Pella but a free-living athetine of some sort. Maybe Acrotona?

Unfortunately, it was a little too cold today and the previous night’s drop in temp. didn’t help either, oh well. Still got some interesting shots of Crematogaster workers interacting with queens that had recently dropped their flight wings. This species of Crematogaster is polygynous, not sure but I interpreted this behavior as workers trying to recruit new queens. Oddly, the queens weren’t cooperating with the workers.

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I heard some pleasing news today and it made my day.

This photo’s from Costa Rica. I think it’s a Microdon sp., checking out the nest entrance. Honestly, I know they’re myrmecophilous so I should be able to identify the genus from other hover flies, but the characters that define them are found in the wing venation, so kinda hard to check out in the wild.

Thanks to a comment by Martin, this fly was identified as a species of Lepidomyia. Martin also informed me that the larvae are unknown, but those of a related genus develops in decaying wood. Makes sense, this individual was scouting a tree hole opening, which was coincidentally occupied by an ant colony.

Whatever, gestalt is a taxonomist’s best friend anyways.

Gestalt betrayed me…

Microdon checks out an ant nest entrance.

Lepidomyia checks out a tree hole opening.

And, some more myrmecophiles from Sat.

Camponotus were preparing for colonial proliferation.

Reproductives patiently wait for the right moment.

Reproductives patiently wait for the right moment.

Some case-bearing leaf beetles can be found with ants, where they feed on nest refuse. I’ve previously collected adults and larvae from Arizona, Arkansas and Oregon. The ones from Arizona and Oregon were in the genus Saxinis.

I kept them alive. We'll have wait and see what the adults look like.

I kept them alive. We’ll have wait and see what the adults look like.

Poster child myrmecophile, Myrmecophilus, hey it’s right in the name!

An immature female, you can see her still-developing ovipositor.

An immature female, you can see her still-developing ovipositor.

The current revision that treats North American taxa, in my opinion, is not that reliable. I don’t think hind leg spine number is a stable enough character to be used in identification. I have seen taxa with unequal numbers between their hind legs. I think molecular data will give us an entirely new perspective, just as the research in Japan has. I suspect this is what people call Myrmecophilus pergandei.

There is some evidence to suggest that individuals develop according to the size of their hosts. Therefore, some species are known to demonstrate extreme size polymorphism. Could this really be the reason behind these observations?

There is some evidence to suggest that individuals develop according to the size of their hosts. Therefore, some species are known to demonstrate extreme size polymorphism. Could this really be the reason behind these observations?

More Masoncus!

The female yesterday was a little teneral. The ones today are fully pigmented, and look, an immature!

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