Step into my parlor…

Thomisid spider waiting for breakfast. Boca Raton, FL, May 8, 2015.

…said the spider to the lady beetle. And yet, nothing happened.

This morning before work I went out and, as usual, was taking pictures of whatever I could find in the yard. I found this lovely Southern Sprite damselfly (first of the season):

Southern Sprite (Nehalennia integricollis). Boca Raton, FL, May 8, 2015

Southern Sprite (Nehalennia integricollis). Boca Raton, FL, May 8, 2015

It’s always a pleasure to see these relatively rare damselflies. (Odd, too, how abundance is so tied to locale: Everglades Spite (N. pallidula) is considered very rare, while Southern Sprite isn’t, and yet I get dozens and dozens of the former over several months and very very few of the latter. I guess being near the Everglades is conducive to the occurrence of Everglades Sprite? While most people across the range of these insects are not near the glades…)

When I was finished with the sprite’s photo session I wandered over to the patch of dune sunflower I have growing along the drive. I noticed one flower had two petals sort of curved upward toward each other, indicating, most likely, the presence of a hunting spider. (That is, a spider that hunts without using a web.) It had tied the petals together with a strand of silk; you can see them curling up toward the camera in the photo below:

Thomisid spider waiting for breakfast. Boca Raton, FL, May 8, 2015.

Thomisid spider waiting for breakfast. Boca Raton, FL, May 8, 2015.

Thomisid spiders are commonly known as “crab spiders” (not to be confused with Gasteracantha cancriformis, commonly known in south Florida as a “crab spider,” although most naturalists call it the spiny-backed orbweaver to avoid confusing it with the “true” crab spiders like the one above).

The true crab spiders are so called because their front pairs of legs are drastically elongated, much like the pincers of a crab. It’s one of the largest spider families, with over 2,000 species worldwide. There are at least 130 species in 9 genera in the United States, so identification to species level is left to the true spider experts, the araneologists (as distinct from the arachnidologists, who study arachnids in general, which includes arthropods from other orders such as scorpions, mites, ticks, and chiggers, in addition to the Daddy Longlegs, which aren’t true spiders at all).

While I was taking pictures of this unusual flower-trapping arrangement (normally I see the petals of the flowers curled down, rather than up), I noticed a wee little lady beetle about to become breakfast:

Lady beetle, meet spider. Boca Raton, FL. May 8, 2015.

Lady beetle, meet spider. Boca Raton, FL. May 8, 2015.

And then the strangest thing happened: the spider just remained motionless while the beetle climbed on the spider’s back, tumbled off onto the disk portion of the flower, and then scurried away out of sight!

Let's make a closer acquaintance.

Let’s make a closer acquaintance.

So long, and thanks for stopping by. (The beetle is visible to the lower left of the spider.)

So long, and thanks for stopping by. (The beetle is visible to the lower left of the spider.)

I wasn’t able to snap a picture of the scene as the beetle left, but I was certainly surprised to see what I assumed would be a typical predation scenario turn into nothing at all.

In case you’re curious, the lady beetle looks very much like the “metallic blue” lady beetle, Curinus coeruleus, although it’s by far the smallest one of them I’ve ever seen.


Marshall, S., & G.B. Edwards. 2008. Florida’s Fabulous Spiders, 4th ed. Hawaiian Gardens, CA: World Publications.

Ubick, D., P. Paquin, P. E. Cushing, & V. Roth (eds.). 2005. Spiders of North America: An Identification Manual. Keene, NH: American Arachnological Society.

Dragonflies and damselflies returning to the yard

Eastern Pondhawk (Erythemis simplicicollis). Boca Raton, FL, March 20, 2015.

After a dry beginning to March (and no rain since then, but at least the heat’s moderated a bit for the past few days), the odonates have started returning to the yard, just in time for the equinox!

One or two of them run into mishaps:

Watch where you fly! Halloween Pennant (Celithemis eponina) served up for breakfast to a spiny-backed orb weaver (Gasteracantha cancriformis). Boca Raton, FL, March 18, 2015.

Watch where you fly! Halloween Pennant (Celithemis eponina) served up for breakfast to a spiny-backed orb weaver (Gasteracantha cancriformis). Boca Raton, FL, March 18, 2015.

but by and large they are still the most formidable airborne insect predators out there. Most of them sprint to safety as I approach, although the Blue Dasher is often more docile,

Blue Dasher (Pachydiplax longipennis). Boca Raton, FL, March 19, 2015.

Blue Dasher (Pachydiplax longipennis). Boca Raton, FL, March 19, 2015.

as is a chilly Eastern Pondhawk in the early morning:

Eastern Pondhawk (Erythemis simplicicollis). Boca Raton, FL, March 20, 2015.

Eastern Pondhawk (Erythemis simplicicollis). Boca Raton, FL, March 20, 2015.

The smaller and daintier damselflies are generally more approachable with a camera even after the sun has warmed them up a little; after the “chill” of the morning burns off, most of my dragonflies sprint away as I approach. Damselflies, on the other hand, sit still so you can sneak up on them. And, if you look at the bottom of the photo below, other creatures have little difficulty approaching as well.

Rambur's Forktail (Ischnura ramburii). Boca Raton, FL, March 20, 2015.

Rambur’s Forktail (Ischnura ramburii). Boca Raton, FL, March 20, 2015.

Since I didn’t notice the spider until after I’d come inside to view the photos on the screen, I have no idea what kind it is. Presumably a flower spider of some sort; it’s quite small, given that the damselfly is no colossus itself.

Happy first day of spring!

Damsels in Distress

Rambur's Forktail (Ischnura ramburii) and breakfast. Yamato Scrub, August 31, 2014.

You may remember that I volunteer with the Palm Beach County Department of Environmental Resource Management from time to time, helping them clean up and maintain the natural areas here in Boca Raton. Last weekend there was a work party at Yamato Scrub, and we were there for sunrise, coffee, donuts, muffins, and—oh, yeah—work. We trundled wheelbarrows full of sand from the sand mound to a few areas of sidewalk between the two recreated wetlands on the site. There’s a sand berm between the northern pond (the deep one) and the southern wetland (much larger and shallower). When the rains come, the sand next to the sidewalk tends to follow the water downhill, leaving the sidewalk higher and drier, which will eventually cause the sidewalk to fracture and degrade. So our work party helped to shore up the sand around the sidewalk, delaying the inevitable for another few seasons.

We also did the traditional work party routine: trash pickup, with long-handled grabbers and trash bags, cleaning up as much of the area as we reasonably could. You always find the usual stuff that people discard (cans, bottles, wrappers, shotgun shells), but you’re also always on the lookout for the fun stuff. For example, when we did the planted area in the parking lot, my covolunteer Dan found the weirdest object I’ve yet seen: a fully inflated toddler’s waterwing. What on earth was that doing in the parking lot of a scrub area?

As we were taking trash from around the perimeter of the wetlands, we ran across some pretty blue flowers, which our ERM coordinator ID’ed for us as Blue Curls (Trichostema dichotomum); I was able to snap a decent image with my iPhone and its little Olloclip macro lens:


Blue curls (Trichostema dichotomum</em.). Yamato Scrub, August 30, 2014.

Blue curls (Trichostema dichotomum

We also ran across some hogplum (Ximenia americana) in flower; the contrast between the delicate blooms and the long, wickedly sharp thorns, never ceases to impress me (particularly when I get too close!). I couldn’t get good focus with the iPhone, so here’s a shot from the next day with my real camera:

Hog plum (Ximenia americana). Yamato Scrub, August 31, 2014.

Hog plum (Ximenia americana). Yamato Scrub, August 31, 2014.

Of course, during a work party I can’t exactly tote around my real camera and rig, so the iPhone photos just serve to remind me of what’s there until I can get back to the site with my DSLR and its macro lens to do some real “work.” For example, here’s a shot of the blue curls taken with my Nikon instead of my smartphone:

Blue curls (Trichostema dichotomum</em.). Yamato Scrub, August 31, 2014.

Blue curls (Trichostema dichotomum

Nice to get some focus across the entire image!

In fact, the main reason I went back to the site the day after the work party was that while we were working, I noticed some damselflies that intrigued me—spreadwings of some sort, but without my macro lens, I wasn’t able to get a sharp enough picture to ID them. So I returned the next day with my real camera and set about hunting them down. Turns out I wasn’t the only hunter in the wetlands: this enterprising Rambur’s Forktail (Ischnura ramburii) captured an unwary (or just unlucky) Atlantic Bluet (Enallagma doubledayi).

Rambur's Forktail breaking its fast on Atlantic Bluet. Yamato Scrub, August 31, 2014.

Rambur’s Forktail breaking its fast on Atlantic Bluet. Yamato Scrub, August 31, 2014.

Damsels in distress, indeed! The fork tail in the picture above is spreading its wings, but only to keep its balance and flight-readiness; when resting normally, it folds them over its back, like so:

Rambur's Forktail (Ischnura ramburii). Yamato Scrub, August 31, 2014.

Rambur’s Forktail (Ischnura ramburii). Yamato Scrub, August 31, 2014.

Here’s a closer look at her enjoying her breakfast:

Rambur's Forktail (Ischnura ramburii) and breakfast. Yamato Scrub, August 31, 2014.

Rambur’s Forktail (Ischnura ramburii) and breakfast. Yamato Scrub, August 31, 2014.

After some hide and seek, I was able to relocate some of the spreadwings and, as I might have expected, they’re the only species we have here in Boca as far as I know: Carolina Spreadwing, Lestes vidua:

Carolina Spreadwing (Lestes vidua). Yamato Scrub, August 31, 2014.

Carolina Spreadwing (Lestes vidua). Yamato Scrub, August 31, 2014.

Carolina Spreadwing (Lestes vidua). Yamato Scrub, August 31, 2014.

Carolina Spreadwing (Lestes vidua). Yamato Scrub, August 31, 2014.

But when you’re intent on hunting down one particular insect, there might be others who are just as intently trying to hunt you down!

Biting fly, Tabanid family. Yamato Scrub, August 31, 2014.

Biting fly, Tabanid family. Yamato Scrub, August 31, 2014.

A word of caution if you plan to hang out in the wetlands: there are plenty of predators on the wing! For example, a few dragonflies (top, Little Blue Dragonlet, Erythrodiplax minuscula; Middle, Common Green Darner (Anax junius); bottom, unidentified.

Erythrodiplax_minuscula_YS_20140831 Anax_junius_YS_20140831 Dragonfly_YS_20140831

And if you’re the first one on the trail, you might find a few roadblocks put up by other kinds of predators, like this spider (I think it’s the tropical orb weaver, Eriophora ravilla, but I’m not sure):

Orb weaver. Yamato Scrub, August 31, 2014.

Orb weaver. Yamato Scrub, August 31, 2014.

You need to look sharp if you don’t want to walk out of the scrub wearing spider silk! Now, if only those biting flies had been the bugs that these spiders were eating… Oh, well.

New backyard spider: Cyrtophora citricola

Cyrtophora citricola. Boca Raton, FL, July 29, 2014.

Gardeners in south Florida are the inverse of the typical beachgoer: instead of looking forward to a sunny day for reading, we look forward to a cloudy morning for weeding! August days, even in the morning, can be brutal. Earlier this week my weather station reported a heat index of 110°F! So when we get rain overnight followed by lingering clouds, we jump at the chance to get a bit muddy while trimming back the overgrown foliage and pulling out the weeds from the flower beds.

When we get the chance to do this, we often discover new and unusual things, like this spider:

Cyrtophora citricola. Boca Raton, FL, July 29, 2014.

Cyrtophora citricola. Boca Raton, FL, July 29, 2014.

Here’s another view, where you can see the unusual shape of the abdomen:

Cyrtophora citricola</eM. Boca Raton, FL, July 29, 2014.

Cyrtophora citricola, Boca Raton, FL, July 29, 2014

The arrow-shaped posterior makes it look a bit like another spider I’d found in the past, the trashline orbweaver, but instead of being in a typical orb-shaped web, it was in the middle of the craziest web I’d ever seen, draped all over one of my small silver buttonwoods. The web was roughly spherical, but nowhere near as organized as a funnel web, and it was made of dry, not sticky, silk. Here’s a shot from the UF/IFAS featured creatures website—can you find the orb in that mess?

Colony of Cyrtophora citricola filling space between palm leaves. Photograph by G.B. Edwards, Division of Plant Industry, Florida Department of Agriculture and Consumer Services.

Colony of Cyrtophora citricola filling space between palm leaves. Photograph by G.B. Edwards, Division of Plant Industry, Florida Department of Agriculture and Consumer Services.

Turns out the web belongs to Cyrtophora citricola, a tropical tentweb orbweaver. This is an old world species introduced to Florida in the Miami area around this most recent turn of the century—at least, it was first written up in 2000; see summary by Edwards (2006).

Here is the first description of their arrival in Florida (Halbert 2000):

Cyrtophora n. sp., a spider: Several specimens have been collected in webs in Ficus benjamina at a nursery in Homestead (Miami-Dade County; E2000-545; Duraid I. Hanna; 2 March 2000, and E2000-965; Julieta Brambila;12 April 2000). Cyrtophora species are orbweaving spiders that make a lot of barrier webbing in addition to the orb. The barrier web tends to collect a lot of plant debris. The spiders appear to hide in or near the tip of a curled leaf and look like a piece of dead leaf or other detritus. The webs are about the dimension and volume of a basketball. If numerous, their webs could be conspicuous features in the landscape, and could possibly be considered a nuisance by some homeowners. NEW UNITED STATES RECORD.

These are interesting spiders, classed as orbweavers despite the fact that they produce a very large tent-like structure of nonsticky silk in addition to their horizontal rather than vertical orb-shaped web. (Most people encountering their crazy tentlike web have trouble even locating the orb in the middle of all that 3D craziness!) Here are some fun facts about these little critters:

  • They are colonial, often establishing large living aggregations with dozens to scores of square meters of web; this large coverage enables them to overcome the disadvantage of nonsticky silk.
  • They have rather oddly shaped bodies, with a trademark look to their rear end: a “horizontally oriented bifurcation at the posterior of the abdomen,” as Edwards (2006) puts it.
  • Like Allocyclosa bifurca, the only other spider in Florida that it resembles in any way, shape, or form, C. citricola webs arrange eggs and detritus in a characteristic “trashline.” (I find it very interesting that the two “spiky orbweavers with bifurcated posteriors” in Florida share this behavioral trait in addition to their morphological similarity.)


Cyrto– means humpback or hunchback; phor means thief, while phoras means fruitful, bearing. Not entirely sure which meaning Forsskål had in mind when he named the species in 1775 (posthumous publication arranged by his colleague Niebuhr). Citricola, it seems clear, is for the citrus trees where presumably the first specimens were found.


Edwards, G. B. 2006. Cyrtophora citricola (Araneae: Araneidae), a Colonial Tentweb Orbweaver Established in Florida. Entomology Circular No. 411 Fla. Dept. of Agriculture & Consumer Serv. Mar/Apr 2006 Division of Plant Industry.

Halbert SE. 2000. Arthropod Detection. Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Tri-ology 39(2): 7.


Dune sunflowers, spiders, and moths, oh my!

Dune Sunflower (Helianthus debilis). Boca Raton, FL, July 9, 2012.

Dune sunflower, Helianthus debilis, is a commonly recommended plant for Florida native gardeners. It’s in the daisy family (Asteraceae), and it’s very pretty:

Dune Sunflower (Helianthus debilis). Boca Raton, FL, July 9, 2012.

Dune Sunflower (Helianthus debilis). Boca Raton, FL, July 9, 2012.

Yellow rays, purple disc flowers, loads of pollen—very attractive to bees and butterflies.

Halictid bee on Dune Sunflower. Boca Raton, FL, May 26, 2013.

Halictid bee on Dune Sunflower. Boca Raton, FL, May 26, 2013.

It self-sows and reseeds annually, so once you’ve got it established, you don’t have to do much except remove it from places you don’t want it! It grows best in “dune” environments: sandy areas in full sun, hence the common name.


Since it grows to cover such a large area (it’s often used as a groundcover), it naturally develops a bit of an ecosystem of its own. I’ll frequently find flower spiders gleaning insects attracted by the bright colors and abundant pollen. Until the other day, though, I hadn’t thought of it as a larval host plant for lepidoptera young, but now I’ve seen a couple of things that have started me thinking.

For example, here’s a flower crab spider (family Thomisidae, species incertae, most likely Mecaphesa celer, formerly known as Misumenops celer) enjoying a fly of some kind (order Diptera, perhaps family Sarcophagidae, but without a view of the head, it’s hard for a nonspecialist like me even to get to the family level on this one!):

Flower spider with fly. Boca Raton, FL, June 13, 2013.

Flower spider with fly. Boca Raton, FL, June 13, 2013.

But here’s another flower crab spider with what looks like a tiny caterpillar in its mouth:

Flower spider with caterpillar. Boca Raton, FL, June 13, 2013.

Flower spider with caterpillar. Boca Raton, FL, June 13, 2013.

If you’re not convinced that there’s a caterpillar there, here’s a close-up:

Detail of flower spider w/caterpillar in Dune Sunflower.

Detail of flower spider w/caterpillar in Dune Sunflower.

Once I noticed that caterpillar, I started looking for more, and sure enough, these Dune Sunflowers appear to be some sort of host plant (maybe just a roosting location during the day?) for what look like grass-skipper or moth caterpillars. Here’s one without a spider munching on it; it appears to be munching on the flower instead:

Caterpillar on Dune Sunflower. Boca Raton, FL, June 13, 2013.

Caterpillar on Dune Sunflower. Boca Raton, FL, June 13, 2013.

I haven’t been able to find much on Helianthis debilis as a host plant for lepidopterans; according to the interwebs, its only attraction is as an adult nectar source.

My Wagner, though, lists sunflower as the host plant for the common looper moth caterpillar, which this caterpillar resembles fairly closely (although it looks much MORE like the related soybean looper, which does not feed on sunflower, at least according to Wagner, and MOST like the found-in-Florida Cabbage Looper, Trichoplusia ni, which isn’t specifically associated with sunflowers).

So I’m going to tentatively ID it as Cabbage Looper, and if someone wants to tell me I’m wrong, I’m happy to listen. I don’t think the caterpillar will mind, either way.


Wagner, D. (2005). Caterpillars of Eastern North America. Princeton UP.

New photos: Spiny-backed orbweaver


Tooling around the house in preparation for Halloween, I found this little lady near the ficus that our neighbor planted to mark the property line:

She’s a spiny-backed orbweaver, Gasteracantha cancriformis. I wrote about this species last year around this time (spiders are most numerous and visible in the fall), but I finally got a couple relatively decent pictures of one and wanted to show the world.

I’ve been trying for some time now to get an image that shows this darn spider’s eyes. I’m beginning to think I’ll have to capture one and pose it, but that goes against my photography ethic: don’t do anything that might cause distress to the subject (or the photographer)! (I don’t have a bug-collecting kit with soft forceps; it might be about time to invest in one.)

Your eyes are like little moons… well, sort of.


I’ve written about Selenops spiders before, but thought I’d give it another go, now that there’s such a cooperative one living in a crack on the landing:

Most spiders build webs, so they rely more on their sense of touch to sense the vibrations of prey that have become stuck in their traps. Other groups of spiders, though, like the jumping spiders (Salticidae) and the wolf spiders (Lycosidae) have excellent vision, because they rely on it not only for safe and effective locomotion but to capture their meals.

As you might guess, web-building spiders have relatively small eyes, while jumping spiders and wolf spiders normally have at least one extra large pair among the eight eyes they typically carry. (For a comprehensive chart of spider eye arrangements, visit this page at Here’s a typical jumping-spider eye:

Notice how the eyes in the middle (the median eyes) are quite a bit larger than the next pair outboard, and there’s another pair that stare straight sideways mounted a bit higher up on the head. This arrangement enables the jumping spider (typified here by the pantropical Menemerus bivittatus, or Gray Wall Jumper) to execute their unparalleled feats of precise acrobatic locomotion.

The web-builders, on the other hand, generally have small, equal-sized eyes, like this friendly Eriophora ravilla I photographed last January:

Spiders in the family Selenopidae, on the other hand, lie somewhere between these two groups. They don’t build webs, but they hang out in crevices, between the glass and the mullion in your windowpane, and other such confined spaces, capturing prey by ambush. So their vision has to be pretty good, but they don’t need the extraordinary depth perception of the jumping spider.

And as you might expect, their eyes are somewhere in between the jumpers and the web-builders. They have four median eyes arranged in a semilunate arc (hence the allusion to the moon goddess, Selene, in their family and genus names), and two very large lateral eyes that presumably enable them to see quite well out the sides of their lair:

Combine that with the rather fearsome-looking jaws (called chelicerae by araneologists) and you have a beast that, while probably quite beneficial to the average homeowner, is usually considered to be less than endearing.

Leetle bitty spiders, Part 5


Menemerus bivittatus, also known as the Gray Wall Jumper, is a pantropical species of jumping spider that occurs in four of the southern United States: Florida, Louisiana, Texas, and California (here’s an image from Los Angeles that was posted to bugguide a couple of years ago). It’s unclear (to me at least), why it has this disjunct distribution, but it was apparently introduced into Florida from the Old World tropics as far back as 1912. It is associated almost exclusively with human habitations.

Based on a sample size of one (i.e., me), it seems that when a curious backyard naturalist (i.e., me) approaches it with a camera, it waves its chelicerae (the front “feet”) in a warning fashion or threat display, although what kind of threat this 1-cm long arachnid with fangs too weak to penetrate human skin can pose is beyond me. Unfortunately, I wasn’t able to capture this behavior with my camera; every shot I have shows her with her chelicerae demurely folded in front of her:

One thing I discovered about this spider is that it has an incredibly quick reaction time to the flash of a digital camera. When I was taking these pictures, each time I clicked the shutter button while the spider was in one place, in perfect focus, but in the split second between when the flash fired and the exposure was made, the spider literally jumped to a different location. (I suppose the large eyes characteristic of the Salticidae, or jumping spiders, make it rather sensitive to bright lights!)

It was quite a challenge to get any of the shots to come out in focus; I pretty much had to guess how far away and in what direction the spider would jump and prefocus in that general area. A few shots did come out, but I had hoped for far more interesting and diagnostic images, based on how docilely the spider let me approach, despite the foot-waving display. Oh, well. They didn’t turn out too badly, I suppose.

Like most spiders, despite the rather fearsome appearance, they are beneficial to humans on account of their diet. The UF “Featured Creatures” web page for this species mentions that

All free-living stages feed primarily on small Diptera which alight on buildings, although they are capable of capturing large crane flies twice their length, and larger, heavier muscoid flies.

For reference, here’s a crane fly (with 64 North American genera and some 1600 species, family-level (Tipulidae) ID is all you can really get from a photograph):

Crane fly (Tipulidae family), Boca Raton, FL, February 15, 2012

The etymology of M. bivittatus was fun to figure out. The derivation of the genus name, which translates to something like “moon thigh,” was a bit of a puzzle until I happened to turn to a book I don’t own, but hope to some day:  Spiders of North America: An Identification Manual has as its 73rd and last chapter a magisterial etymological dictionary that is a model of scholarship. According to this work, it was Eugène Simon who, in 1868 at only 20 years old was not yet a master of Greek—but the first edition of his Arachnides de France had already been in print for 4 years!—who named this genus. The first part of the name, Menemerus, is supposed to come from the Greek mene, moon, but (had Simon mastered Greek more fully, as he did later in life) it should have ended in –s (menes). The second part of the name, –merus, is Greek for thigh. Apparently Simon meant the name to refer to the crescent-shaped “thigh” of the male palpal femur.

The specific name, bivittatus, is a lot easier: Latin for two-striped (bi + vitta), referring to the stripes on the carapace, easily seen in this view:

Leetle bitty spiders, part 4: Hentzia sp.


One of the more interesting “free-range” groups of spiders is the family Salticidae, the jumping spiders. They have one pair of marvelously large eyes situated prominently up front, which is what provides them the depth perception they need to coordinate their incredible jumping ability. They use this ability to leap from point to point to capture their prey and to get around from one plant to another.

One day as I was out taking my routine census of the wild lime bush in the back yard, I noticed that two adjacent leaflets had been sort of stuck together. Now, whenever you notice something like that, you have to get your camera out to see if you can find out what did it. It could be a lepidopteran larva just taking a nap or getting ready to pupate; it could be a spider setting a trap; or it could b something else. In this case, it was a small (teeny, maybe 5 mm long) jumping spider in the genus Hentzia. There are five species in the continental United States, with only four in Florida: H. palmarum, H. mitrata, H. grenada, and a south Florida specialty (for the U.S., at least; it’s also found in the Bahamas and on Cuba) is H. chekika.

This particular spider looks like this:

You can see the large eyes that are characteristic of all salticids, and you can see the body shape that is characteristic of the genus Hentzia: “somewhat elongate,” according to the last revision of the genus, from 1989. If you want to get technical about it, here are some more precise characteristics as noted by Richman:

The genus Hentzia is here defined by the presence of both pencils of hair below the posterior median eyes and spatulate hairs on the ventral retromargin of the first patella and distal femur. These characteristics are most pronounced in the female, especially in regard to the hair pencils. Males often have elongated chelicerae and somewhat elongate bodies.

These spiders have a circum-Caribbean distribution, and most of the different species are presumed to have resulted from island speciation (the tendency of isolated breeding populations of a once-more-widespread species to develop unique traits that define it as a separate species).

Although there are only a few species from which to choose, I was unable to take a photograph that showed sufficient detail to place the spider to the species level, but I’m happy to know that it’s a Hentzia.

Here is what I believe to be the egg sac of this same (or perhaps another) individual; it gives its location away by the way the adjacent leaves stick together:

And today as I was tending the firebush (sadly, the scale saga continues) I noticed a tiny creature scuttle from the top of the leaf to the side away from me. Curious, I flipped the leaf over and snapped a few pictures; it was so small I didn’t have any idea what I’d found. But it turns out to have been one very happy Hentzia (presumed) spider:

Leetle bitty spiders? Nunh-uh! Argiope species in Florida yards


I never finished the miniseries I had started last December on spiders found in and around my yard; here is the fourth installment, starring two species of orbweaver that are commonly encountered in gardens both in Florida and elsewhere. They are so common, in fact, that they have common names, unlike the vast majority of spiders: Argiope argentata is known as Silver Garden Orbweaver or Silver Argiope, while A. florida is known as the Florida argiope. Florida has two other Argiope species, A. aurantia and A. trifasciata, but I have yet to encounter them in my Florida back yard, so today’s post is just about “known species” to me.

One of the reasons I leave my Florida yard a bit unkempt is so that spiders, those efficient and abundant predators, can have more time to control any bad bugs that might be around. A neat and trim yard, with a beautiful lawn and well-defined flower beds and no overgrown bunch grasses or wildflower beds is one that requires chemical control of harmful insects (which also “controls” beneficial ones), and dozens of hours of mowing, weeding, trimming, clipping, hedging, and weed-whacking. I try to think that it’s not just my own laziness that urges me instead to let nature take her course. Instead, it’s principle: I do what I can to maintain a semblance of ecology in my garden (a la Grissell’s idea of garden ecology). If said principle happens to result in less “work” for me, and more photographic and entomological opportunities, well, so be it.

So that’s why I haven’t yet trimmed my muhly grass, despite the fact that its stalks and blooms are yellow, not purple, and why I’ve left the “weedy” species (Bidens alba, Richardia grandiflora, etc.) around the fences unwhacked: these “unsightly” areas of overgrowth allow many more hiding places for insects, and attachment sites for spiderwebs. And as a result I’ve got literally dozens of spiders (Argiope species, Leucauge species, Gasteracantha species, and more) helping me control the flies and other annoyances that might otherwise rise to “treatment required” levels.

Here, though, without further ado, are the pictures of the two Argiope spiders. A. argentata, the more commonly encountered spider, first:

These are not small spiders; this one is at least half an inch long, but remember, spider measurements exclude the leg length. If you add in the legs, it’s two inches across; if you add in the “stabilimenta” woven into the web, the visual impression of this spider is daunting, indeed.

Here’s a picture of one of the business ends, the spinnerets on the abdomen:

The liquid silk that flows from the silk glands hardens very soon after flowing through these nozzles; it’s the various chemical constituency of the silk combined with the treatment it receives post-spinneret that determines whether it’s “sticky” (viscid) or not. The function of the stabilimentum isn’t known for certain, but some experiments show that birds are slightly better at avoiding webs with stabilimenta than those without. And a bird flying into the web, rather than being a tasty prey item for this spider, just means that she has to rebuild her web.

Back in 1982, entomologist Thomas Eisner and ornithologist Steven Nowicki tested that hypothesis at Archbold Biological Station in central Florida demonstrating that before dawn, when birds are not yet active, both marked and unmarked webs survive at equal rates: about 80%. But after dawn, the unmarked webs started disappearing, until by noon only 8 percent of them remained, while fully 60 percent of the marked ones, those with “stabilimenta,” remained intact. And while they had only one data point of a bird flying into a web (an Eastern Towhee encountering an unmarked web), it remains the most convincing explanation of the function of this visual marker.

The other type of Argiope spider I found in my garden was actually photographed last year, in December, but I didn’t realize what it was until I tried to determine for sure what today’s photos (of A. argentata) were. Argiope florida looks pretty similar to A. argentata, but the abdomen of the latter has a golden back end with a few (6, in this case, although that might be variable) silver triangles there, while the former has three long projections of silver along its back half, as you can see in the fuzzy photo below:

This image shows a relatively small individual that I found in my front courtyard, and it was in a relatively inaccessible location, so the photograph isn’t perfect. Had I realized how relatively rare it is in my yard, though, I’d have made sure to make some better pictures of her. As it is, this is the only individual of A. florida that I know I’ve encountered here; all the others (and there are nearly a dozen on the property right now, of varying sizes) are Silver Argiopes.
There is no stabilimentum present in the photo above, but the webs of all Argiope spiders usually do have them. While Eisner’s experiment proved to his own satisfaction the function of the stabilimentum, other araneologists (specifically spider scientists; arachnologists study the class Arachnida, which includes, but is not limited to, spiders) are not as convinced. Marshall and Edwards, authors of Florida’s Fabulous Spiders, review the four proposed functions as follows:
  1. as implied by the name, the stabilimentum strengthens or stabilizes the web (Eisner and Nowicki disproved this hypothesis by comparing the strength of de-stabilimentized webs (with their stabilimenta dissolved by alcohol) with those that still had them and finding no difference)
  2. bird avoidance (the conclusion reached by Eisner and Nowicki)
  3. insect attractant
  4. camouflage for the spider itself (the conclusion favored by Marshall and Edwards, according to “recent research”)

Whatever the case, the debate is fun, and so is finding and photographing these wonderful animals.


Eisner, T. 2003. For Love of Insects. Cambridge, MA: Belknap/Harvard.

Marshall, S., & G.B. Edwards. 2008 Florida’s Fabulous Spiders, 4th ed. Hawaiian Gardens, CA: World Publications.

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