Notable Texas Eleodes

Some notable species of the diverse genus Eleodes from our trip to Texas this past summer.

Eleodes veterator

This first species is Eleodes veterator, a coastal dune inhabiting species. If you’re familiar with what Eleodes species typically look like, this is an oddball: flattened and fuzzy, it’s actually kinda cute.

These individuals are taking advantage of some messy campers by feeding on an old lemon rind.

Eleodes labialis

Eleodes labialis

The second species is an elusive species, Eleodes labialis, previously only known from the two original type specimens. A species presumably adapted to living between boulders and within the crevices along canyon walls of the Rio Grande, it sports rather long antennae and legs for the genus. I guess you could argue the eyes are slightly smaller then what you would expect for an Eleodes of this size.

Nicagus occultus withstands the wind

From a Texas trip with Kojun and James. A nice find at the dunes. Here, a female tolerates the gusting wind awaiting a male at dawn.

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Ampulex canaliculata

I was inspired by AntRoom’s post on rearing the emerald cockroach wasp, so I set out to find our North American local Ampulex.

I saw this female carrying a juvenile roach up a tree by its antennae (very typical), but failed to get my camera ready in time. Fortunately, I was able to grab a couple shots of her carrying debris back to her nest which she uses to plug up the entrance.

A female Ampulex canaliculata carries debris back to her nest.

A female Ampulex canaliculata carries debris back to her nest.

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Her and other individuals were nesting in holes made by wood boring beetles and debris for blocking the entrance could be found nearby by collecting frass generated by the same wood boring beetles.

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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Regressing against Ethanopium

I’m including stats in a larval description I’m working on, like, now. Give it up for Dyar’s Ratio!

I took Jim’s course on larval biology (one of the best classes I have taken, btw, and Keith still holds a grudge cause I got a better grade in the class – hey, we all miss-IDed the lymexylid larva in our collections, OK?) and learned about Dyar’s Rule/Ratio, whatever you want to call it, and Dyar’s personal weirdness (he was all about building dangerously illegal tunnels in his back yard).

Once I heard about Dyar’s Ratio, I was determined to include it in my research, and here I am, including it, but with really no utility, admittedly, but that’s OK. Just don’t tell the editors. Hey, at least the concept had never been tested in rove beetles, right?

Here’s my new fav., courtesy of Krystaal: Dengue Fever, a Cambodian Psychedelic Surf Rock influenced group. Enjoy Ethanopium a cover (also a soundtrack for Broken Flowers, FYI), but a nice segue into the band nonetheless.

Cryptic species complex in a North American Deinopsis species.

Sometimes it can be tricky deciphering the difference between intra- and inter-specific variation – differences between individuals of a given species as opposed to those that exist between representatives of different species – without consulting molecular divergence. When molecular data is lacking, taxonomists typically compare a large sampling of individuals across the available morphological variability in order to identifying species boundaries; taxonomists typically look for breaks in a seeming continuum of morphological variation.

In the case of the genus Deinopsis, there was a noticeable lack of available specimens for this sort of approach when the genus was revised in 1979. Understandable given the scarcity of Deinopsis, they seem to be a rare group.

Genitalic variation in Deinopsis harringtoni, illustrated by Klimaszewski in his revision of the genus.

Genitalic variation in Deinopsis harringtoni, illustrated by Klimaszewski’s transformative revision of the genus.

In Klimaszewski’s comprehensive revision of the genus, genitalic vatiation (a feature commonly used to distinguish species) in Deinopsis harringtoni, a rather widespread northeastern North American species, was determined to represent intra-specific variation.

Deinopsis species occur in swampy and more muddy banks of slow to stagnant bodies of water compared to Gymnusa, a related genus that I previously introduced how to collect. Incidentally, I had the opportunity to collect Deinopsis on several occasion last summer.

Exemplar Deinopsis habitat.

Exemplar Deinopsis habitat from Vermont.

Among the Deinopsis specimens I collected were two series which I had tentatively identified as D. harringtoni, but males from the two samples sported different genitalic morpho-types. Considering the possibility that this genitalic variation in fact represented species boundaries, I sequenced both D. harringtoni samples to compare their pairwise molecular divergence.

Modified by CombineZPModified by CombineZP

Low and behold, comparing partial COI sequences of the tentative D. harringtoni specimens in reference to a Palearctic species, D. erosa demonstrated over 20% sequence divergence between every pairwise comparison of the three Deinopsis specimens. The morphological differences between D. erosa and harringtoni qualitatively appear significant, suggesting that the degree of molecular divergence I found in the partical COI sequences sufficiently identifies species boundaries.

What was previously considered intra-specific variation in D. harringtoni genitalic morphology may in fact indicate boundaries between species that: geographically occupy close to overlapping ranges with little to no external morphological identifiers – Deinopsis harringtoni could be a complex of cryptic species. Pretty exciting stuff and definitely warrants more collections to be made across the country to sample more populations. This will be fun and challenging since these guys can be pretty rare.

Deinopsis spp sequences Mesquite