Sign Challenge #1 Reveal: Spinybacked Spider Egg sac

February 10th, 2013 - 12:25 PM | Filed under Sign Challenges | 2 Comments

This reveal for Sign Challenge #1 is long overdue. Here’s the challenge photo again:

~15mm long | August 23, 2012 | Sebring, FL, USA

~15mm long | August 23, 2012 | Sebring, FL, USA

Commenter Daniel Heald correct guessed it was a spider egg sac. Here’s another angle:

Dorsal view

Dorsal view

When I took the photos, I assumed it was a cocoon. I was curious to see what moth would emerge, so I took it home with me.

After looking through Tracks & Sign of Insects and Other Invertebrates, I realized it was actually an egg sac for a Spinybacked spider (Gasteracantha cancriformis). In fact, I had seen many of those spiders in the area. The egg sac’s yellow silk, dark longitudinal line, and placement on the underside of a leaf all point to this species.

In Spiders of the Carolinas, L. L. Gaddy notes that in over twenty years of fieldwork he’s not seen the egg sac or male of this species. Perhaps I’m just lucky, but I suspect I’m more of a leaf flipper than Gaddy. The egg sacs are placed on the undersides of leaves, which is where I’m always checking for caterpillars.

I was curious to see the spider eggs, so I peeled back a few layers of the silk and found the spiderlings had already hatched. Turns out they stay in the egg sac for weeks before emerging.

Spiderlings revealed

Spiderlings revealed

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Closer look

I had hoped to see the spiderlings grow, but they all died after a few weeks.

References:

Spiders of the Carolinas
by L. L. Gaddy
Tracks & Sign of Insects and Other Invertebrates:
A Guide to North American Species

by Charley Eiseman and Noah Charney

Mystery Egg Mass

January 29th, 2012 - 9:59 PM | Filed under Featured Photos | 4 Comments

25mm long | July 12, 2011 | Victorio Siqueroli Park, Uberlandia, Minas Gerais, Brazil

What looks a bit like peanut brittle is presumably an egg mass. I found this on lichen covered bark at the base of a tree. Overall it was about 25mm long, which would make each of the embedded eggs less than 2mm long.

Side view

Each egg appears to be elliptical, with a sort of knob at the exposed end.

Closeup

I don’t have a clue what is responsible for this, so I’d love to see comments from anyone that might have an idea. I’ve been through the “Eggs and Egg Cases” chapter of Tracks & Sign of Insects a few times already, but I haven’t spotted any likely suspects.

Mystery Eggs

January 26th, 2012 - 9:40 PM | Filed under Uncategorized | 1 Comment

Egg, ~1mm wide | July 12, 2011 | Victorio Siqueroli Park, Uberlandia, Minas Gerais, Brazil

These curiously textured and patterned eggs were placed on a dried leaf tip. I don’t recall ever seeing anything quite like them. I don’t know what they are, but I’d guess moth eggs.

Some of the ones around the edge are a bit crumpled.

Edge shot, showing crumpling

Here’s a wider view, to give you some context for the placement.

Wider shot, showing placement

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

Aetalionid

November 26th, 2011 - 9:22 AM | Filed under Featured Photos | 1 Comment

11mm long | July 8, 2011 | Victorio Siqueroli Park, Uberlandia, Minas Gerais, Brazil

This atypical treehopper belongs not to the family Membracidae, but to a separate family, Aetalionidae.

Searching around on the internet, it seems most photographers generally seem to catch these hoppers while tending their eggs, as shown here.

To learn a bit more about the family check out Ted C. MacRae’s post from earlier this year.

Reference:

500 Insects:
A Visual Reference

by Stephen A. Marshall

Battleship-shaped Ootheca

November 14th, 2011 - 6:41 PM | Filed under Featured Photos | No comments

31mm long | July 6, 2011 | Victorio Siqueroli Park, Uberlandia, Minas Gerais, Brazil

I saw quite a few of these oddly shaped things. My guess would be that they are the oothecae (egg masses) of a praying mantis. I’ve read that each species of praying mantis has a distinctive looking ootheca. After quite a bit of searching, I’ve been unable to find one that looks quite like this.

This one was on some sort of succulent plant, but I found others on tree trunks and various other plants.

Another view

Lacewing Eggs Comparison

October 5th, 2011 - 9:48 PM | Filed under Featured Photos | 1 Comment

9mm high | July 5, 2011 | Victorio Siqueroli Park, Uberlandia, Minas Gerais, Brazil

I assume these are hatched lacewing eggs, though I think there are other critters that lay stalked eggs as well. What I found interesting was how long the stalks are relative to the eggs. The lacewing eggs I usually find have relatively shorter stalks. Compare the hatched ones above with some unhatched ones below that I found in a park close to home.

5mm high | August 27, 2011 | Twelvestones, Roswell, GA, USA

Searching around the internet I see two common explanations for why eggs are laid on stalks. First, the stalks make it more difficult for predators such as ants to reach the eggs. The stalks are sometimes even coated with a repellent substance. Second, lacewing larvae are cannibalistic and the stalks serve to keep keep newly hatched larvae away from each other.

Webbed Eggs

July 25th, 2011 - 7:58 PM | Filed under Featured Photos | No comments

9mm high | July 3, 2011 | Tupaciguara, Minas Gerais, Brazil

I’m not sure what type of eggs these are, but I saw several clutches like this. I thought at first perhaps a fungus had grown over them and that might be the case. I’m more inclined to believe the webbing was added as some sort of protection by whatever is responsible for the eggs.

I suppose these could also be cocoons, but I’d be surprised if the larvae managed to align themselves so well.

Had I found these in my own backyard, I’d have kept them to see what emerged.

Ants Tending Leafhoppers

July 6th, 2011 - 7:37 PM | Filed under Featured Photos | 3 Comments

July 2, 2011 | Monte Alegre, Minas Gerais, Brazil

These ants are tending to some treehopper nymphs. Most of the ants are busy collecting honeydew, but the one on the bottom has noticed me and is on alert. I accidentally bumped the branch after this shot and all of the ants started running around looking for something to attack. I held up a leaf for a background here so that the ants would stand out.

In this next shot, I’m assuming the white areas are either treehopper eggs or a protective covering for the eggs. One of the adult treehoppers is also visible here, a darker shade of red than the nymphs.

Egg mass and adult treehopper

In this final shot, there are more eggs, another adult and some late instar nymphs.

More eggs and some late instar nymphs

Amplypygids – Tailless Whip Scorpions

May 14th, 2011 - 9:00 AM | Filed under Featured Photos | 1 Comment

20mm | January 19, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

These fearsome looking arachnids have an order to themselves, Amblypygi. Though commonly called tailless whip scorpions or whip spiders, they are neither. Intimidating though they may look, they aren’t dangerous and possess no venom. They are quite timid in fact, and I had to take care not to scare them away while photographing them.

Here’s how you might expect to see one actively moving about, with its oversized first pair of legs outstretched.

Longest legs extend outside frame

That first pair of legs is modified for use as antennae. They wave them about, sensing and probing. While the body of this one measured only 2cm, each one of those antenniform legs was 8cm long!

Eight Eyes

The have flattened bodies, useful for hiding in crevices and other tight places during the day. They hunt at night, and I usually see them on the trunks of trees. These first images, however, were of one I spotted on the side of a creek bank. This next one was on a downed tree that had fallen across the same creek.

Raptorial Palps Extended

Its palps were initially extended as shown here, perhaps in preparation for an ambush. After I spooked it, it drew them in closer to its body.

What I found most interesting though, were a few females I spotted carrying egg sacs.

Female with egg sac

Actually, the egg sac is glued in place. She’ll carry her eggs around like this for at least 3 months, during which time she generally won’t eat. If she did, the eggs might become unglued.

Egg sac closeup of another female

Based on this genus key, all these individuals appear to be in the genus Paraphrynus. In fact, they must be Paraphrynus laevifrons. I realize the linked pages are for La Selva specifically, but La Selva and this location are both in the Caribbean lowlands. Further, iabin shows only this single species for that genus, and even has a collection record not far from my site.

Amblypygids really are fascinating creatures. If they lived in my area, I’d probably keep them temporarily as pets to observe them further.

Reference:

Arachnids
by Jan Beccaloni