Tapinoma Ant Observations

May 2nd, 2012 - 10:31 PM | Filed under Featured Photos | 1 Comment

April 13, 2012 | Twelvestones, Roswell, GA, USA

For several days I had noticed ants racing along the bricks at the base of one of my garage doors. I finally took a closer look to see what could be keeping them so busy for so long. They were streaming between a hole in my house and somewhere out in the front yard. I tried following, but these ants are tiny, only a few millimeters long. I quickly lost them in some pine straw.

Moving out

Turns out they were moving out of my house. The ones heading toward the yard were carrying eggs, larvae, and pupae. As I watched them though, I noticed something else leaving with them that didn’t look quite right.

That's not an ant

When I first saw one of the critters above, I knew it wasn’t an ant. My initial thought was it must have been a tiny roach. That first one was gone before I could react, but I headed inside to grab some containers in hopes of seeing more. Over the course of an hour and a half, I spotted three more and managed to grab a couple of them.

Watching one, it seemed unsure of its course. At times it would bump against some incoming ants and dart away. It would always rejoin the column, but sometimes moving in the wrong direction.

About to right itself

Eventually it would right itself, almost always after encountering an ant carrying a larva or pupa. I’d guess it can’t follow whatever chemical signals the ants are tracking and instead relies on following the cargo.

Follow the larvae

It got me wondering how the ants know which direction to go in. I know they follow a chemical trail, but what tells them which direction they should go? Actually, lots of questions came to mind as I watched them. How do they know it’s time to move? How do they decide on a new nest location?

Later, I gave the freeloaders the white paper treatment.

Dorsal view

I began to wonder if these weren’t crickets. I grabbed Arnett’s American Insects and started skimming the cricket families listed there. When I came to Myrmecophilidae (Ant-loving crickets), I figured that must be it. I briefly thought I might even be able to contribute something to BugGuide, but it turns out there were plenty of photos there already, confirming the identification.

Dorsolateral view

Both the specimens I captured have ovipositors and so must be female.

Frontal view

Rear view

Another shot

I found some good info on these in my Field Guide to Grasshoppers, Katydids, and Crickets of the United States. These crickets only live in ants nests. They apparently feed on oily secretions from the ants bodies, causing no ill effects. Only one species occurs in my area, the Eastern Ant Cricket, Myrmecophilus pergandei. This particular cricket species has been found living with eleven different species of ants.

Speaking of ant species, I decided to try and identify the host ants. Using the key in Ants of North America: A Guide to the Genera, I arrived at Tapinoma. Based on the remarks there, I believe these ants must be Tapinoma sessile. I sacrificed one to see how well the common name of Odorous House Ant applies. It was indeed odorous, and as I mentioned, they were leaving my house.

As I watched the ant column, one other thing caught my attention. Fairly often, I’d notice a much larger ant passing by, about twice as big as the others. I snatched one of those as well.

Queen

Remembering some of Alex Wild’s comments from his blog entry on how to identify queen ants, I recognized this as a queen. That only confused me though, since I had seen perhaps half of dozen of these in the brief time I observed the column. I naively thought that ant nests generally had a single queen. The wikipedia entry for this species says that its nests can actually have hundreds of queens!

I wasn’t familiar with either of these interesting insects when I started watching them. Had I encountered them a week later though, I’d probably have recognized them from a recent post from Alex Wild. He scooped me, but I couldn’t let the opportunity to blog about them pass.

What happened to the ants you might be wondering? Well, they can’t seem to make up their mind. As I write this there is still a column going strong, weeks later. They were steadily moving out for almost a week, but then at some point I noticed they had reversed course and were moving back in. I don’t want to imagine just how many thousands of ants there are somewhere in the walls of my home.

References:

American Insects:
A Handbook of the Insects of America North of Mexico

by Ross H. Arnett, Jr.
Field Guide to Grasshoppers, Katydids, and Crickets of the United States
by John L. Capinera, Ralph D. Scott, and Thomas J. Walker
Ants of North America:
A Guide to the Genera

by Brian L. Fisher and Stefan P. Cover

Crypsis Challenge #13 Reveal: Jumping Stick

September 7th, 2011 - 6:18 PM | Filed under Crypsis Challenges | 2 Comments

82mm | July 9, 2011 | Tupaciguara, Minas Gerais, Brazil

Were you able to find the critter in the photo above? It’s in the lower right corner. Some of you may recognize this as another stick grasshopper in the family Proscopiidae, previously featured in Crypsis Challenge #3. They are so cryptic that I couldn’t resist doing another challenge with this one. Here’s an outline of the grasshopper if you’re still not seeing it.

Grasshopper revealed

Check out how closely the color and texture of the insect matches that of the surrounding vegetation.

Can you distinguish animal from plant here?

Here’s another image where it’s blending in fairly well.

Another cryptic scene

And here, I intentionally placed it on a nearby rock so its features would stand out.

Jumping stick, looking more like the grasshopper it is

They have such interesting faces that I couldn’t resist a profile shot. It actually looks a bit sinister here.

Profile shot

Most of those that commented found the critter. A few even guessed the identity correctly, but even the incorrect guesses were plausible. Good job, everyone.

Katydid

July 4th, 2011 - 1:15 PM | Filed under Featured Photos | No comments

January 21, 2011 | Finca La Isla, Limon Province, Costa Rica

If not for the long antennae, this large katydid could easily be mistaken for a grasshopper.

Large Bark Katydid

May 17th, 2011 - 5:40 PM | Filed under Featured Photos | 1 Comment

75mm | January 19, 2011

Armonia Nature Preserve, Limon Province, Costa Rica

 

This large katydid was trying to remain inconspicuous on the side a tree. With a body three inches long and antennae over twice that, it was difficult to miss. I considered making this a crypsis challenge, but it seemed too easy.

In the second photo, it’s in the lower right corner.

Crypsis Challenge #10 Reveal

April 10th, 2011 - 3:17 PM | Filed under Crypsis Challenges | 3 Comments

I didn’t intend to leave this challenge open for quite so long. Unfortunately, other things in my life sometimes have to take precedence over this blog, even if I’d rather it be the other way around. :)

Looks like the challenge was more difficult than I expected. Commenters who suggested a katydid were on the right track, but this looks like a cricket to me. Here’s the original photo and another version where I’ve crudely outlined the cricket.

Cricket, outlined

January 19, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

I provided the outline to show the position and to show just how long the antennae are. Here’s a closer photo, sans antennae.

Cricket revealed

The hind tarsi here are hidden below the tips of those surprisingly long cerci. The visible ovipositor makes this a female and apparently a wingless one.

I’m going to suggest this might be a species in the family Mogoplistidae, the scaly crickets. The presence of lepidoteran like scales is diagnostic. Up close this one does appear to have a sheen to it.  That family also has wingless females. I’m prepared to be corrected on this suggestion though.

Identification Challenge #5 Reveal

November 28th, 2010 - 8:43 AM | Filed under Identification Challenges | No comments

As usual, Ted C. MacRae was right on all counts for this challenge:

January 28, 2010 | Caraça Natural Park, Minas Gerais, Brazil

I thought perhaps the swept-back antenna across the bottom third of the photo might throw people off. Not so.

Here’s a better shot of the katydid which was cooperative enough to allow some good closeups. This should put all the body parts shown above in context.

Katydid

My sister guessed a dragonfly via a Facebook comment. I can see the resemblance so not a bad guess.

A Walkingstick with Wings

October 23rd, 2010 - 6:30 PM | Filed under Featured Photos | No comments

Walkingstick | January 28, 2010 | Caraça Natural Park, Minas Gerais, Brazil

We don’t have that many species of walkingsticks here in the Southeastern US. None of the ones I’ve encountered have wings. So this one looks odd to me.

Remember the jumping sticks? Here’s one more photo of one of those so you can see how easy it is to distinguish the two based on their antennae.

Jumping stick | January 28, 2010 | Caraça Natural Park, Minas Gerais, Brazil

Crypsis Challenge #4 Reveal

October 23rd, 2010 - 9:42 AM | Filed under Crypsis Challenges | No comments

Hopefully it didn’t take more than a few seconds to spot the katydid in this image.

January 27, 2010 | Caraça Natural Park, Minas Gerais, Brazil

Crypsis Challenge #3 Reveal

October 13th, 2010 - 10:30 PM | Filed under Crypsis Challenges | 3 Comments

Did you find the critter hidden in this image?

January 28, 2010 | Caraça Natural Park, Minas Gerais, Brazil

Ted C. MacRae did and correctly identified it as a stick grasshopper in the family Proscopiidae. As a reward, my next post will be a tiger beetle.

If you still need help finding it, here’s an outline and a cropped version.

Outlined

Cropped

Hopefully this one was bit more challenging. I didn’t spot the critter in this setting. It was originally higher up in some foliage and only jumped to the ground in a failed effort to escape my photographic pursuit.

Note the short antenna which makes it easy to distinguish these from walkingsticks.

Side View

Castner mentions that these insects are occasionally called “Nixon grasshoppers” because their face resembles a caricature of the former president with exaggerated jowls. What do you think?

Nixon?

Here’s one with a missing foreleg  I encountered a few days earlier. With an extended forehead, it might be a different species.

January 28, 2010 | Side View

Dorsal View

References:

Amazon Insects:
A Photo Guide

by James L. Castner