Abandoned Hornet Nest over the Chattahoochee River in Fall

October 14th, 2012 - 10:04 PM | Filed under Featured Photos | No comments

October 13, 2012 | Roswell, GA, USA

In Fall, bald-faced hornets enter the autumn of their lives. Surviving adults, no longer responsible for providing masticated prey for the colony’s growing young, enter into a retirement of sorts. They abandon their nest and spend their last days, up until the first frost, feeding on nectar. Only mated queens survive to found new colonies the following year.

 

 

Leafrolling Mystery Caterpillar

April 29th, 2012 - 7:43 PM | Filed under Featured Photos | No comments

20mm | April 5, 2012 | Twelvestones, Roswell, GA, USA

Earlier this month I was checking for anything interesting in my backyard when I came across this caterpillar in a rolled up leaf on viburnum. I decided to try and rear it to get an identification.

It turns out it was a final instar because it pupated beneath its leaf within a week, sometime around the 9th.

Pupa within leaf shelter

I removed the pupa from its webbing for some cleaner shots.

11mm | Underside of pupa

Dorsolateral view

I checked daily for the adult, but sadly it eclosed while I was away on vacation, sometime around the 20th give or take a few days. When I got back I found a dead and beat up adult. I prefer live images of a fresh adult that I can release later, but I’ll take what I can get here I guess.

10mm | Adult

Based on similar looking moths, I decided it must be a Tortricid moth in the genus Archips. Looking through all the species images on BugGuide, I decided it most resembled Archips grisea.

It has what appears to be a costal fold on the forewing, indicating it’s probably a male.

Note enlarged area near base of forewing

This page has a description of the larva which is consistent with the caterpillar I found. One distinguishing feature is a completely black head and prothoracic shield.

Uniformly black head and prothoracic shield

The page also says the first pair of legs are black while the other two pair are pale green and unmarked. Check.

Leg colors consistent with larval description

Everything suggests this is Archips grisea except the host plant. Either this is something else, or viburnum hasn’t been recorded for this species.

I’m asking for some expert help here. If it checks out I’ll update BugGuide as there are currently no larval images for this species (or anywhere on the internet that I can find) and no record for Georgia.

Stingless Bees

November 21st, 2011 - 10:27 AM | Filed under Easter Eggs, Featured Photos | No comments

10mm wide entrance | July 6, 2011 | Victorio Siqueroli Park, Uberlandia, Minas Gerais, Brazil

These stingless bees have made their nest inside a termite mound. Earlier in the day, the bees weren’t clustered around the entrance like they are here. Instead they were simply flying in and out occasionally. This was taken late in the day though, and I suspect they are preparing to seal the entrance for the night. In the photo below, you get a better sense of how the nest is situated in the termite mound.

Though these bees are stingless, they aren’t defenseless. Do you see the clump of resin in the upper left? Looks like an ant has been encased there. I wonder if the bees perhaps mobbed it and secreted all that resin.

Nest in termite mound

One of the common names for these bees in Brazil is torce-cabelo, which means hair-twister. I once got a little too close to a nest for the bees’ comfort. In return they made me quite uncomfortable. At first I didn’t realize what was happening. Suddenly they were crawling all over me, getting tangled up in the hair on my head, my arms, and anywhere they could grab hold. Having experienced that, I’m not likely to forget their common name.

Termites at Work

September 13th, 2011 - 5:21 PM | Filed under Featured Photos | 1 Comment

July 9, 2011 | Tupaciguara, Minas Gerais, Brazil

Just after dark, termites started emerging from below ground. Here they appear to be excavating. The darker soil has been brought up from below by workers while guards form a defensive perimeter.

Marimbondo-chapéu – Hat Wasp

July 11th, 2011 - 2:15 PM | Filed under Featured Photos | No comments

July 9, 2011 | Tupaciguara, Minas Gerais, Brazil

The local common name for these social wasps is marimbondo-chapéu in Portuguese or hat wasp in English. The name refers to the form of the nest, seen above.

Seen from below, I’d say it looks more like a sunflower. They are really packed in there. I’d estimate there are probably a couple of hundred of them.

Sunflower?

Here’s another crop that I like of that same image.

A different crop

You’ve probably noticed by now these images were taken during the day. So what are all of them doing hanging out on the nest? Taking a siesta? I wondered the same thing. I spent around 45 minutes taking pictures and attempting to gauge just how closely I could approach without alarming them. During that whole time, not a single one flew off or arrived.

Hanging out

I began to wonder if these wasps might be nocturnal. When I returned a few hours after dark, I had my answer. At that point, the nest was quite active, with dozens flying around. A quick internet search for “nocturnal wasps Brazil” gave me the genus, Apoica, a genus known for its nocturnal habits.

When reviewing the images, I noticed they have relatively large ocelli, which undoubtedly helps them navigate and find prey at night.

Note the large ocelli

Most of these photos were taken with my 100mm macro, sometimes combined with my teleconverter. The closest I ventured was for this habitat shot, taken with my wide angle zoom at its widest 18mm setting.

Habitat shot

I don’t have my copy of Latin American Insects with me, but I just checked it via google books. Hogue refers to this genus as parasol wasps, also because of the shape of the nest. He notes that only the common species, Apoica pallens, has a yellow abdomen.

Reference:

Latin American Insects and Entomology
by Charles L. Hogue

Stingless Bee Nest

May 26th, 2011 - 6:36 PM | Filed under Easter Eggs, Featured Photos | No comments

January 20, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

This stingless bee nest was nestled in the hollow of a tree. The nest entrance is only about a centimeter wide, making the bees themselves only 5 or 6mm long.

As their common name suggests, these bees have no sting to defend themselves. Knowing that, I got quite close. Harmless though they may be, they certainly look mean.

Looking mean

New arrival below

In that last photo, you can see a new arrival hanging below the nest, with pollen visible in the basket on its hind tibia.

According to Hogue, there are three genera of stingless bees. Lestrimelitta can be eliminated here because it doesn’t have a pollen basket. Of the other two, Melipona is larger, hairier and the wings don’t extend beyond the tip of the abdomen as they do here. These must then be a Trigona species.

In this last photo, check out the length of the centipede passing in the background. This is an “easter egg”, that I didn’t notice when I took the picture. Even while reviewing, I initially mistook it for a climbing vine, except it was missing in the next photo!

Centipede passing in the background

Reference:

Latin American Insects and Entomology
by Charles L. Hogue

Apterostigma collare

May 15th, 2011 - 8:38 PM | Filed under Featured Photos | 1 Comment

4mm | January 19, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

I spotted the structure below on the underside of a large leaf. I really didn’t know what it was, and I gently poked at it. It was quite fragile as it turns out, and it fell open to reveal an ant nest. I then immediately regretted not having taken a photo beforehand. The next day I was lucky enough to find another one, also pictured.

6cm x 4cm | Unexpected ant nest

4cm x 2cm | Nest with an ant entering

These nests are the work of an ant in the genus Apterostigma. Ants of Costa Rica has an info page for this genus in Costa Rica. I tried to use the key there to identify these, but it was a bit technical for me. I’m basing the species identification on the statements from the site that seem to indicate that only Apterostigma collare builds these nests under leaves. There are some more photos of nests at that same site.

Like the well-known leaf-cutting ants, Apterostigma ants grow fungus for food. They make their nests out of the fungul hyphae.  Other Apterostigma species in Costa Rica build their nests underground, in leaf litter, inside rotting logs, and in other protected locations. At least one other species, Apterostigma robustum, builds its nests on exposed tree trunks, but it takes care to camouflage them with bark fragments. Apterostigma collare nests, in contrast, visibly stand out on the undersides of leaves.

Ants inside nest, fungal hyphae visible on leaf surface

I counted around 20 ants in that nest that I unintentionally opened. It didn’t occur to me at the time to try and identify the queen. In any case, none stood out as any different than the others at the time or in the images after review.

It’s not clear to me what exactly the ants provide for the fungi to grow on. I did notice what looked like some bits of insect exoskeletons mixed in.

Ant worker

There’s definitely all sorts of odd bits visible inside the nest.

Frontal view

These long-legged ants move about pretty slowly, so I took advantage of the opportunity to take quite a few photos.

On the move, albeit slowly

The ants themselves were varying shades of orange, some darker than others.

Individual coloration was variable

After a while, I could see some of the workers were picking up small globular items. I’m still not sure if those are larvae or pupae, but I assume it’s one or the other.

Worker carrying larva?

Here’s a closeup view of one, where at least a few structures are visible.

Larva?

Here are just a few more images of these interesting ants.

Worker

All Apterostigma ants, by the way, are hairy like the ones shown here.

Worker, preening

Maybe one of the ant people who read this blog can share a few more interesting tidbits about these ants. Hopefully I won’t get corrected on my identification.

Webspinners

March 13th, 2011 - 5:35 PM | Filed under Easter Eggs, Featured Photos | 5 Comments

10mm | January 18, 2011 | Gandoca-Manzanillo NWR, Limon Province, Costa Rica

I don’t think I’ve ever photographed webspinners before, so this represents another first from my most recent trip to Costa Rica. That’s notable to me because they have an order all to themselves, Embioptera.

As I walked the coastal trail leaving Manzanillo, I noticed many trees with webbing on their trunks. I stopped to look at a few, but I didn’t see any movement. I suspected webspinners were responsible, but it was only later when I decided to probe one of the webs that the webspinner above emerged. It didn’t seem very happy with the situation, and moved quickly to try and take refuge within the web again. Eventually it chewed a hole through which it disappeared.

While reviewing the photos, I noticed that I managed to also photograph a smaller, presumably less mature webspinner beneath the web.

Note the younger webspinner in the upper left

A long streamlined body befits the narrow passageways they create within their silken lairs. Forced to navigate tight spaces, they often must move quickly in reverse. Their cerci, those appendanges at the tip of the abdomen, are highly sensitive analogs to antennae to aid in quick backwards movement.

Note long cerci extending from abdomen

Only males develop wings, so the large one that I photographed here must be male. All the photos I’ve seen of adult males show the wings covering the abdomen. I therefore assume this is an immature male, despite its relatively large size.

Only males develop wings

Webspinners create their webs using the large tips of their forelegs. The thickened portion of the leg contains many silk-producing glands.

Note enlarged leg tips, which contain silk glands

Here’s a few views of the galleries they create. Despite staring at them in the field, I couldn’t spot anything beneath the web. Occasionally I’d see some movement, but once it stopped, I lost track of the source. Now, having the advantage of looking at my high resolution shots, I can see at least three webspinners hidden in the photo on the left. Click on the image to see a larger version and see if you can find any.

Click to enlarge; can you find any?

The main gallery continues

One thing I’m left wondering is how vulnerable webspinners might be to parasites. Their web is strewn with frass, which must be a beacon for something like a parasitic wasp. They must indeed move quickly to avoid such things. I did also notice that they are covered with fine hairs. Maybe they use these to detect movement that’s transmitted through the web.

Reference:

Encyclopedia of Insects
by Vincent H. Resh and Ring T. Carde

Large Wasp Nest

February 22nd, 2011 - 8:33 PM | Filed under Featured Photos | 1 Comment

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

I spotted this wasp nest way up in the canopy. I like how it’s open-ended at the bottom, exposing the comb inside.

It’s amazing to me the variety of forms that tropical wasp nests take. One day I’d like to do a compilation of all the ones I’ve photographed over the years.

Leafcutter Ants Nesting Above Ground

February 20th, 2011 - 12:56 PM | Filed under Featured Photos | 1 Comment

January 17, 2011

Cahuita NP, Limon Province, Costa Rica

I was watching some leafcutter ants and I noticed they disappeared inside the trunk of this tree palm(?). I thought perhaps they were just passing through, but another trail ended on the other side.

In the second photo you can see some leaves being carried along one of those stems. One of the nest entrances is about one third from the left and one third from the bottom.

I thought that leafcutter ants always had underground nests. Perhaps that’s the case here as well, with the majority of the nest still being underground. It’s a swampy area though, and the area behind the tree was submerged. It makes me wonder how leafcutter ants nest in areas that are often inundated with water.