Parasitoid Wasp Emerging

December 7th, 2011 - 9:34 PM | Filed under Easter Eggs, Featured Photos | 1 Comment

July 8, 2011 | Victorio Siqueroli Park, Uberlandia, Minas Gerais, Brazil

Each one of these eggs from the underside of a leaf was parasitized by a wasp.  Their barrel shape with round fringed caps suggests they might be stink bug eggs. Had a stink bug nymph emerged, the caps would have been neatly opened. Instead, they each have a roundish hole chewed in them. In fact, there’s a parasitoid wasp straggler chewing its way free from the rightmost egg.

I might be seeing things, but you can almost make out the wasp’s body through the transparent egg shell.

View from the other side

I didn’t notice at the time, but a mite came along.

Mite approaching

Reference:

Tracks & Sign of Insects and Other Invertebrates:
A Guide to North American Species

by Charley Eiseman and Noah Charney

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.

Scale Insects

October 2nd, 2011 - 10:08 AM | Filed under Easter Eggs, Featured Photos | No comments

July 5, 2011 | Victorio Siqueroli Park, Uberlandia, Minas Gerais, Brazil

I assume these are scale insects. When I saw them I remembered the mysterious sign I spotted earlier in the year in Costa Rica. After seeing this, I think scales were probably responsible for that.

Note how they’re arranged along the central leaf vein. They’re undoubtedly taking plant juices through that midvein.

Click on the photo for a larger version and see if you scan spot a small mite (an “easter egg” I didn’t know about when I took the photo). Then see if you can find its recently cast off skin!

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

Micropezid, ovipositing

April 30th, 2011 - 10:27 AM | Filed under Easter Eggs, Featured Photos | 3 Comments

8mm | January 19, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

While recently reviewing my shots of this fly in the family Micropezidae, I was surprised to find that I unknowingly got a shot of her laying an egg. Here’s another shot for comparison, where she has concealed her ovipositor beneath her abdomen.

Ovipositor concealed

Here’s a crop from the first photo, showing the ovipositor and the egg.

Ovipositor and egg

Everything I’ve read indicates that most larvae develop in decomposing matter, so it seems strange she would be placing an egg on a leaf surface. Perhaps this is  just a method of random distribution, and the egg just falls where it may on the ground below.

I saw lots of micropezids, also called stilt-legged flies, during my stay. They are fairly easy to recognize with their long legs and curious behavior. I usually see them on leaf surfaces like this, walking around and waving their forelegs in front of them like antennae. This behavior combined with their overall form gives them the appearance of an ant or a wasp perhaps.

Frontal view

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

Pelecinid Wasp

November 1st, 2010 - 6:31 PM | Filed under Easter Eggs, Featured Photos | 1 Comment

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

Wasps in the family Pelecinidae are distinctive and easily recognized by that long thin abdomen. I’ve see them closer to home as well, but I can’t recall if I’ve ever gotten a decent photo. I do remember chasing after quite a few in vain or watching as one teased me from someplace just out of reach. I got lucky with this one.

What I thought was a red marking turns out to be a small mite.

There’s only one genus, Pelecinus, for this family. There appears to be at least two described species in the tropics.

That long abdomen is used for ovipositing in the soil. Females probe for and oviposit on scarab beetle larvae.

Reference: Wikipedia

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.

Tick Anatomy Lesson

October 25th, 2010 - 6:42 PM | Filed under Easter Eggs, Featured Photos | No comments

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

This tick is one of the largest I’ve ever encountered. I’m happy to say it was the only one I saw.

Ticks often wave around their forelegs while perched like this, hoping to grab on to some passing potential host.

When viewed from the side, there’s an interesting bit of anatomy exposed.

Side view (do you see the smaller mite bringing up the rear?)

I wondered about the purpose of that large hole on the tick’s side so I did some research. It’s called the spiracular plate, and it’s basically a tube into the tick’s breathing system. Calling it breathing might be a stretch though. It’s really more of a passive gas exchange. The shape of spiracular plates are also used by taxonomists as a way of distinguishing various types of ticks.

Based on the large overall size and the shape of the mouthparts, I suspect this is a species in the genus Amblyomma.

A Caterpillar to Avoid

October 22nd, 2010 - 9:31 PM | Filed under Easter Eggs, Featured Photos | 3 Comments

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

I found a couple of these large caterpillars very near to each other. First the one above and then the one below. I believe they are a species of Automeris.

With those spines and colors, it’s pretty obvious they are to be avoided. Each one of those spines is like a little hypodermic needle bearing venom.

Here are some closeups.

Head

Spiny cluster

And here’s a particularly intimidating display.

Back off!

So what would mess with this spiny critter? I discovered while reviewing photos of the latter caterpillar that there was a small fly up to no good. Sorry for the photo quality. These are extreme crops.

Fly approaching

Fly feeding

I’m pretty sure that’s a biting midge in the family Ceratopogonidae. Some, like this one, will feed on the blood of other insects. I actually found a reference and image of one feeding on a related caterpillar.

Neotropical Ceratopogonidae (Diptera: Insecta) By Art Borkent, Gustavo R. Spinelli (Google Books link)