Mating Snout Beetles

February 14th, 2011 - 5:54 PM | Filed under Featured Photos | 2 Comments

2mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

These beetles are tiny. Each one is only a few millimeters long.

Reddish Tortoise Beetles

February 13th, 2011 - 11:19 AM | Filed under Featured Photos | 4 Comments

4mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

There were quite a few of these reddish tortoise beetles feeding on this banana plant.

Banana plant

They feed on the large leaves, scarring them in a distinctive way.

Sign from feeding

Here you can see one munching its way forward, carefully feeding only between the leaf veins.

Machinelike feeding precision

Did you notice the little hitchhiker above? Looks like some sort of parasitic wasp to me. I suspect this is probably a female beetle, and the wasp is just hanging out until she lays eggs, which the wasp will then parasitize. Here’s a closer look.

Parasitic wasp closeup

They’d often fly away from me once I started taking pictures, but it was no trouble to find another one.

Another individual

I like their furry little feet.

Portrait

Update: Marshall’s 500 Insects has a photo of a similar looking tortoise beetle, identified as a Spaethiella species.

500 Insects:
A Visual Reference

by Stephen A. Marshall

Colorful Snout Beetle

February 6th, 2011 - 9:00 PM | Filed under Featured Photos | 3 Comments

12mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

I really love the colors on this snout  beetle. Check out the detail. The image is not quite as sharp as I’d like, but just look at all those little colorful scales.

Detail

Blister Beetles Defoliating

December 22nd, 2010 - 4:47 PM | Filed under Featured Photos | 1 Comment

January 31, 2010 | Tupaciguara, Minas Gerais, Brazil

This plant was being devoured by dozens of these attractive blister beetles. Above I’ve caught one with a leaf fragment in its mouth. Below, you can see how they’ve stripped a branch clean. The frass seems to be exiting just about as fast as the plant goes in (must be a good source of fiber).

Beetles Defoliating

As these pictures show, the plant was literally crawling with these beetles.

Working on another branch

The dark backgrounds here are an effect of the camera flash. This was actually happening in broad daylight. How are they able to risk doing that? Blister beetles are so named because they defend themselves with a caustic compound, cantharidin, found in their blood. Predators soon learn to avoid them.

I found some online pictures of Epicauta species resembling these (example).

My web searching also turned up a nice post at Myrmecos, showing the reflexive bleeding.

Finally, there’s lots of good info at this University of Florida Featured Creature page. I saw there that Epicauta species are notable for eating leaves, whereas most other blister beetles limit themselves to flowers. That’s more evidence that these might be a species in that genus.

Some Army Ant Observations

October 31st, 2010 - 11:06 AM | Filed under Featured Photos | 8 Comments

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

That’s the general scene. I encountered these army ants on the side of the trail towards the end of the afternoon. The odd thing is that I didn’t see much more than what’s shown here. There were a couple of holes in the ground, outside the shot above, but roughly in the upper left and lower right. Despite some searching in the nearby vicinity, I didn’t find any other ant trails. But there were ants streaming in and out of the two holes, forming roughly two paths. The bottom path was moving to the right and the top to the left.

Usually when I encounter army ants, I’m hesitant to get down on my hands and knees and start taking pictures. I’m always afraid they will branch off in my direction while my vision is reduced to what’s in the viewfinder, and the next thing I know I’m covered in them. Having said that, army ants don’t generally give me much pause. Even if they have spread out across the trail, it’s pretty simple to just walk right through them.

On this occasion, they seemed pretty contained, so I sat down and started looking closer. It didn’t take long before I started seeing some myrmecophiles (things that live among the ants). Mostly I saw these:

Myrmecophile

Like the ants, they are fast moving and difficult to photograph. I’d spot one, but it would then be hard to frame it. I decided to mostly keep the camera trained on one of the holes, wait to spot one approaching, and then try to get a picture of it before it disappeared underground. What you see above is the best shot I managed to get of one. I believe it’s a beetle, a rove beetle perhaps.

I also occasionally spotted ant pupae being transported.

Ant pupa

Another ant pupa

Here’s one of the larger soldier ants.

Ant soldier towering over workers

Darkness was approaching, and then something unusual happened. The scene became one of chaos as the paths all but disappeared and instead the ants just sort of carpeted the area. Then, paths became discernible again, but the ants had switched directions!

I would have loved to have watched longer, but there just wasn’t enough light so I continued on the path back towards the sanctuary.

I know that some species of army ants are subterranean, so perhaps these are one of those species.

References:

Latin American Insects and Entomology
by Charles L. Hogue
American Insects:
A Handbook of the Insects of America North of Mexico

by Ross H. Arnett, Jr.

Unexplained Beetle Behavior

October 30th, 2010 - 9:36 AM | Filed under Featured Photos | 1 Comment

January 27, 2010

Caraça Natural Park, Minas Gerais, Brazil

This beetle looks like a buprestid to me. The interesting thing is that it’s splitting this leaf lengthwise. In the second photo, you can see where the cut starts in the upper right. That would seem like an odd way to eat, so I suspect there’s some other purpose. Is anyone familiar with this behavior?

There’s also what appears to be a small wasp hanging out on the elytra.

Velvety Yellow Snout Beetle

October 28th, 2010 - 7:28 PM | Filed under Featured Photos | 2 Comments

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

I resisted the urge to touch this one. It just looks so soft.

Longhorned Beetle Damaging Stem

October 25th, 2010 - 10:37 PM | Filed under Easter Eggs, Featured Photos | No comments

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

This longhorned beetle blends in pretty well with these stems.

Some longhorned beetles are known as girdlers and that name might be aptly applied here. See the damage to the stem in the upper right? I didn’t witness it, but I suspect this beetle is responsible. In fact, given the bending of the stem under its head, it may very well have been chewing away when I took this photo. Further evidence is the frass present, indicating it’s been here awhile.

Why girdle? Some beetles that do it deposit an egg in the stem and then effectively kill the stem by chewing a ring into it. The stem beyond the girdle eventually dies and falls to the ground. The stem provides nourishment for the beetle larva and is then well placed for the grub to later escape into the soil where it completes its development.

Mottled Tortoise Beetle

October 24th, 2010 - 3:07 PM | Filed under Featured Photos | 2 Comments

October 10, 2010 | Twelvestones, Roswell, GA, USA

A few weeks ago I found this tortoise beetle, Deloyala guttata, on the underside of a sycamore leaf in a nearby park. Most of the time you only see tortoise beetles safely tucked away inside their “shell” (hence their name). I waited for this one to start moving around so I could get this shot.

Target Tortoise Beetle

October 19th, 2010 - 7:23 PM | Filed under Featured Photos | 2 Comments

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

I’ve seen variations on this pattern for tortoise beetles throughout Central and South America. I often see the species referred to as target tortoise beetles, though a quick google search seems to confirm my suspicion that that common name applies to many different species across several genera.