Bat Bug

Bats are notorious for having a variety of critters that live on or around their bodies. One of the ideas postulated as the reason for bats frequently changing their roost sites is that parasites rapidly become a problem. 



western small-footed bat (Myotis ciliolabrum)


Below, a bat bug (family: Heteroptera) ectoparasite feeding on part of the wing of a big brown bat.



bat bug (family: Heteroptera)

More Fun With Parasites

A few posts back I mentioned the carrion beetle (Nicrophorus carolinensis). In keeping with the theme of parasites*, I am sharing another view of the same beetle with a detailed view of a few extra passengers.



carrion beetle (Nicrophorus carolinensis)


Watching the beetle, I could see the little white mites skittering across the beetle as it walked and flew about. It must be quite a ride for the little insects. Below is a detailed view of the same image with the mite clearly visible on the neck, and few more on the chest. It would roughly be equivalent of having a full size crab wandering around on a human.



carrion beetle (Nicrophorus carolinensis) detail with mites


I posted these images to Flickr for hosting here, and a fellow Flickr alaskanent user posted this comment:

Nice shot! The mites are not parasitic however. They are mutualistic in some cases (beneficial) and in others commensalistic (the mites benefit but the beetles are neither harmed nor helped) and only in rare cases do they actually qualify as parasites. The mites eat fly eggs, thus cleaning carcasses of competitors so there is more food for the beetles.

Vivid Dancer Damselfly With Passengers

This image was in a recent presentation I did, and a member of the audience commented that it must be female because of the "eggs" near the end of the tail. In truth, these are not eggs. I did not notice them when I was taking the photo, but the camera makes it cleanly visible.



vivid dancer damselfly (Argia vivida)


Take a closer look



parasitic mites on the tail of a damselfly


They are mites, not eggs.


Every living creature seems to have to contend with one kind of parasite or another. Some are internal, and some are external. In this case the mites are probably tapping into the blood between segments in the exoskeleton.


I have seen damselflies covered from head to tail in mites, so by comparison this is a light load.

Texas Leech

Leeches are not popular for good reason. They are soft bodied little parasites that will attach themselves to you by whatever sneaky means available. They are ugly too.


So why post a photo of a leech?


Bear with me. If you can get past the unpleasant natural history of this particular leech – I think you might agree that it is at minimum "interesting looking". In fact, I think the pattern is quite remarkable.

aquatic leech

I have been to part of Asia where terrestrial leeches find their way into your clothing, into your bed, and into the shower. I watched one leech wriggle its way through the eyelet of my boot once, and I knew that later, when I removed my boot, there would be an ugly brown leech engorged with blood stuck on my foot. Believe me, i'm no fan.


But I can appreciate a successful evolutionary strategy when I see one.



aquatic leech in various stages of locomotion

Phorid Fly (Pseudacteon obtusus)

As I mentioned in the previous post, imported red fire ants were introduced to the southern U.S. accidentally in the 1930's. They have no natural predators to keep their populations under control.

However the Fire Ant Project at the University of Texas is releasing the fire ant's natural predator from Brazil - the tiny phorid fly – into the areas around Austin and Dallas. There are several species, but they all parasitize the fire ant in a terrifying process that involves eating the ant's brain (from the inside) by a larva implanted by the phorid fly.

imported red fire ant (solenopsis invicta)

The ants, despite being raised in North America where they have no predators, appear to have a instinctive fear of the fly. They respond with a panicked, defensive action that is usually ineffective.

Phorid Fly (Pseudacteon obtusus) hovering above imported red fire ants.

The fly picks an ant that would make a good host, and then hovers above looking for a good moment. When opportunity allows, it will drop suddenly and stab the ant with its ovipositor and implant a single egg. When the egg hatches, it makes its way to the brain and larva will devour the ant's brain until it dies or its head falls off. Nice huh?