Category Archives: Collecting

New video on Leptusa larval behavior

The video demonstrates some Leptusa (probably pusio) larval behavior. Larvae and adults were collected under oak bark in the fall. I’ve been keeping the larvae in the hopes of seeing whether they spin a cocoon and to confirm the adult association, but because I’ve been keeping them inside and they likely need a period of cold diapause, they were slowly dying off. In the mean time, I took the opportunity to take some videos.

An interesting observation I was able to make was on their “dabbing” behavior using the abdominal defensive gland—originally described by Dettner (1993). The highly pigmented nozzle-like end to the gland is used to dab defensive secretions onto aggressors. I am currently coauthoring a paper where we discuss this morphology as a potential synapomorphy for the homalotine-groups of aleocharines, and I’ll update you guys on it further when it is published.

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.