New backyard spider: Cyrtophora citricola

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.)

Etymology

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.

References

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.

 

Fiddlewood caterpillar (Epicorsia oedipodalis) update

Moth_Fiddlewood_flying_20140612

The fiddlewood caterpillars (not their real common name, but since they don’t seem to have a common name I’m calling them that) I discovered the other day haven’t done very well in captivity. I’ve had them in a plastic jar for a couple of days but they haven’t grown at all—still the same 10 mm long as two days ago. Their brothers and sisters that I missed, though, and found two days later on the original shrub, are a bit more robust—already 15 mm long and quite active. I’ve removed those caterpillars and the leaves they were on, and we’ll [...]

Ants bite; they can also tend your garden for you

Epicorsia oedipodalis detail. Note the stemmata rather high on the head

Last weekend I went out to Yamato Scrub for another volunteer clean-up event coordinated by Palm Beach County ERM. We were removing the last of the temporary irrigation installed years and years ago to jump-start the native plants that they imported to the site to replace the acres and acres of Brazilian Pepper and Australian Pine that had grown up over the years since the site was drained by the canals that run all over the place down here.

The irrigation was the typical black poly tubing with smaller tubes for the emitters. But the contractors who installed the tubing [...]

New backyard butterfly: Great Southern White

Great Southern White (Ascia monusta) nectaring on Indian Blanketflower (Gaillardia pulchella). Merritt Island, FL, January 12, 2008.

I’ve been noticing some large, white butterflies in the front yard throughout the month of May; they’ve been a bit hard to photograph with the constant wind and their habit of flying off at top speed when I approach with a camera, so I’m digging into my photo files and showing this version from a January, 2008 trip to Merritt Island National Wildlife Refuge.

Great Southern White (Ascia monusta) nectaring on Indian Blanketflower (Gaillardia pulchella). Merritt Island, FL, January 12, 2008.

Now back to Boca: this June, for the first time ever, I noticed some butterfly eggs on my [...]

Backyard plant: Jamaica caper. Or, flowers attract bees

A honeybee (Apis mellifera resting in a Jamaica caper (Capparis cynophallophora) flower. Boca Raton, FL, May 31, 2014.

Back in April I called my native landscape guru, Melissa McGaughey, because I wanted her advice on some of the things going on around the yard. One of my main concerns was the Jamaica caper in the front yard. It was growing fairly bushy, with lots of what looked like competing leaders, etc. I’m used to it having a more pyramidal shape. When she came by, practically the first words out of her mouth were “that’s the best specimen you have in your yard; I wouldn’t touch it!”

She pointed out that it was just about to enter the budding/flowering [...]

New backyard bird: Downy Woodpecker, or why native plants love birds (and vice versa)

Downy Woodpecker (Picoides pubescent with scale. Boca Raton, FL, May 1, 2014.

From time to time the native plants in my yard, which I do my best to foster, suffer from an overabundance of a certain tiny insect: scale. These insects aren’t scary to most people—they don’t bite, they don’t fly up and startle you, they don’t even move after they hunker down in their chosen spot to feed. But they are rather scary to the plants they parasitize. They latch onto a growing stem, use their piercing sucking mouthparts to penetrate the thin exterior walls, and suck up the vital juices that are supposed to be circulating through the [...]

New backyard plant: Wild Cinnamon

Canella winterana foliage.

The rainy season is right around the corner, so last month I worked on the landscape a little bit. I’d been disappointed in the performance of the gumbo limbo tree out front; it was in the shade of the towering coconut tree that dominates that front yard, and I wanted to see whether it would do better in full sun. It was bothered by scale, the spiraling whitefly infestation that’s hit south Florida, and the sooty mold that both those pests leave in their wake.

After about a month t’s obvious that full sun is not keeping the scale in [...]

Early spring birding in the front yard

It may be only Presidents’ Day on the calendar, but the weather down here in south Florida is nice and the birds are enjoying it. Was outside doing some early morning gardening on this blessed day off work and I heard the R2D2-like witchety watchety-doo of a White-Eyed Vireo across the street. Ran inside for my binoculars and picked up three warblers just in my front yard (palm, prairie, and yellow-rumped), along with Fish Crow and Green Heron. (The Green Heron loves our yard because we have such a rambunctious lizard population; I see him here most mornings prowling the [...]

New backyard butterfly: Ceraunus Blue

Ceraunus Blue (Hemiargus ceraunus). Boca Raton, FL, February 6, 2014.

Today I saw the smallest butterfly I’ve ever seen in my life: the tiny Ceraunus Blue, Hemiargus ceraunus. Most blues, as this family of butterflies is known, are tiny, but I cannot convey to you the utter tininess of this thing. The tiny little stalk of dead weed it’s perched on looks gargantuan in the photo of it:

Ceraunus Blue (Hemiargus ceraunus). Boca Raton, FL, February 6, 2014.

She’s a pretty little thing, though, (I say “she” because females are brown, males are gray) with two prominent dark spots on the leading edge of the forewing and one giant [...]

Birds of Green Cay

Pied-billed Grebe (Podilymbus podiceps), Green Cay Nature Center, November 30, 2013.

Every Saturday after Thanksgiving for the last several years I’ve led the local Audubon Society’s field trip to one of the constructed wetlands in central Palm Beach County: Green Cay. It’s always fun to visit there because the birds know that the people never leave the boardwalk so they’re very tame. Photographers, well aware of this phenomenon, crowd the boardwalk every day of the year. And even those of us who have decent gear but will never be more than a snapshot artist can get a decent snapshot now and then:

Pied-billed Grebe (Podilymbus podiceps), Green Cay Nature Center, [...]