Category Archives: Collecting

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.

Rove beetles get parasitized too, just like everybody else.

I haven’t looked at these images in a long time. These are pictures of Exallonyx,  staphylinid parasitizing Proctotrupidae wasps. I was into trying to rearing these out in college. I would find them by collecting third and final instar larvae in the spring and rearing them out to see if I got any wasps. You’ll see from the images bellow, but the number of individuals are host size dependent, and emerge in a characteristic manner.

I’ve reared three species out on various occasions from 2007-2008 which I’ve uploaded bellow. The first two species emerged from Philonthus larvae and the third from a Platydracus (I’m guessing violaceous since I found it under bark).

Philonthus pre-pupa in a  chamber found under bark in early spring.

Philonthus pre-pupa in its chamber found under bark in early spring.

An Exallonyx larva emerges from the Philonthus pre-pupa.

An Exallonyx larva emerges from the Philonthus pre-pupa.

Exallonyx ready to emerge.

Exallonyx ready to emerge.

Exallonyx sp. 1

Exallonyx sp. 1

Collected 3 individuals from their own subcorticular Philonthus during a field trip to McLean Bogs for a class on insect larvae.

Another Philontus parasitizing Exallonyx sp. larva, exiting its host.

Another Philonthus parasitizing Exallonyx sp. larva, exiting its host.

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Exallonyx sp. 2 pupates, leaving the Philonthus larva a husk.

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Exallonyx sp. 2 pupa begins to darken.

sp. 2

Exallonyx sp. 2

A second species of Exallonyx from another Philonthus at Six Mile Creek, Ithaca, my old hunting ground.

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A closeup of Exallonyx sp. 3 reveals the larva’s minute mandibles and a vague eye spot.

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All in a row, Exallonyx sp. 3 pupae.

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Exallonyx sp. 3

I think this is Platydracus violaceous, the larva was under bark at Six Mile Creek. Unlike Philonthus, this large larva can house multiple individuals of Exallonyx. The larvae all emerge synchronously and orient themselves in the same manner, most notable once they have pupated.

In 2007, I was also able to rear out a Brachonidae from Sepedophilous to pupation, but the adult never successfully emerged. This was unfortunate, since this would have been the first documentation of Brachonidae parasitizing a staphylinid.

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.

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.

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

These are larval Baeocera scaphidiines. The adults are super un-rove-beetle-like.

Baeocera larvae weave in and out the hymenial surface of polypore fungi.

Baeocera larvae weave in and out the hymenial surface of polypore fungi.

Bass are spawning, so I went to check out the fishing over at WCP for 2 hours. The fish were small but active. Even picked up a bluegill with a larger top-water minnow. 3 l.m.bass, max of 12 inches, and 1 blue-G.

Today’s lures were:

Rebel Pop-R, an unstoppable top-water lure. The fact that you can see the bass attacking from below, visually, is amazing.

Rapala Original Floating, something someone picked up for me at a garage sale. The Original is a pricey lure and I was hoping to reek the benefits of tradition. In fact, picked up most of the fish off this baby today. Was using a darker natural color on a cloudy day, I’ve gotta get some brighter colors.

Soil washing and Mayetia

Our collection manager Zack and I have been talking about soil washing in Kansas for some time now. Soil washing, for those of you who don’t know, is a technique used to collect insects (in my case) that are subterranean.

In staphylinids, two lineages, Leptotyphlinae and Mayetiini (Pselaphinae) are exceptional in having taken this lifestyle to its extreme and have appreciably diversified in doing so. The two are surprisingly convergent in morphology, although they occupy disparate regions of the rove beetle tree of life.

Zack had heard a rumor that a leptotyphline, one of these subterranean staphylinids, had been collected from a root-ball in a Kansas prairie. Rumor passes down to me, and this rumor was what fueled our motivation to put into action, what is arguably the most tedious method of collecting.

Step 1. You dig. I don’t know, pick a spot, any spot. We chose a variety.

Me, digging for, well… soil, out in Kansas prairie. Photo courtesy of Zack.

Step 2. For this step, you literally wash the soil. I dumped the soil etc. into trash bin and added water with a hose. After a reasonable amount of water had covered the soil underneath, I sloshed the soil around and skimmed off anything that floated to the surface (this is all organic material, including bugs).

Wash'n some soil.

Washing some soil.

Step 3. I then wrapped any organic material I skimmed from the surface of the water into a bundle, using cheesecloth. I then wrung out this organic bundle of any excess water, wrapped it again, this time in paper towels to further dehydrate, and stored them in labeled baggies until Berlese time.

A bundle of organic stuff. The samples can be stored like this for about a week. So you can transport them back from the field if you're far from home.

A bundle of organic stuff. The samples can be stored like this for about a week, so you can transport them back from the field if you’re far from home.

Step 4. Berlese time. It only took about a day, the stuff wasn’t very dense.

Berlese!

Berlese! A little makeshift spot for this particular project.

Step 5. Sort.

Mayetia peasei are easily packed into a 1 cm square.

Mayetia peasei are easily packed into a 1 cm square.

To some extent, I think I speak for both Zack and I when I say we had low expectations. This added to our surprise when we found close to 20 individuals of a teeny-teeny staphylinid. We go back and forth for some time about whether it was a leptotyphline or Mayetia, finally settling on the later – I mean they’re so damn convergent-looking!

A little more digging around lead to a species identification, Mayetia pearsei. This species is presumably parthenogenic, argued from the fact that not a single male has been discovered, despite some serious effort. Other species in the genus are known to demonstrate extremely female-biased sex ratios.

Mayetia populations aren’t very dense and individuals are poor dispersers. If chances of meeting a mate are unlikely, this can fuel the establishment of parthenogenesis in a population. In some species where males are present in low frequency, they may play a dwindling role as a population marches on towards purely parthenogenic reproduction. Also possible, males are retained for periodic out-crossing, which theoretically can help avoid pitfalls like Muller’s ratchet and environmental instability. Whatever the case, it seems clear to me that this is an interesting system that deserves more attention; several obvious questions and solutions immediately pop in mind.