Wednesday, April 27, 2016

16-19 April 2016 Winter Haven, Florida

Site location map. Click to enlarge.
WHEN, in the Course of human Events, it becomes necessary for one Person to travel to Florida, a decent Respect to the Opinions of Arachnologists requires that I should declare the Cause which impelled me to bring along my spider net.

We hold these Truths to be self-evident, that all pine cones are worthy of tapping, that they are endowed, by their INTERSTITIAL SPACES, with certain unalienable Benefits to Spiders, that among these are Habitat, Refuge, and the Pursuit of Prey.

In other words, since I needed to go to Florida anyways, I took the opportunity to tap a few fallen pine cones while there.  The effort has allowed me to place Florida on the World Map Of Pine Cone Spiders!

Location of Sites 1 and 2
Location of Site 3
I tapped fallen pine cones at three sites in the city of Winter Haven.  Sites 1 and 2 were located in the semi-rural northern end of the city, whereas Site 3 was located in the central suburban part of the city.

Site 1

Site 1 cone source: sand pine plantation
Site 1 fallen cone microhabitat
Site 1 was a sand pine (Pinus clausa) plantation bordered by wetlands, warehouses and light industry.  In the section I sampled, the understory was limited to the occasional palmetto (Serenoa repens), and there was no ground cover present.  Cones, most of which were well opened, rested on needle litter.

Juvenile salticid from Site 1
I tapped 50 cones and collected 6 juveniles spiders from 3 families and probably 4 species.  Four of the spiders were salticids.

Site 2

Site 2 cone source: longleaf
The habitat history of Site 2 was a little difficult for me to figure out.  My guess is that it was a originally a woodland that had been cleared of most vegetation decades ago in anticipation of a housing or orchard development that never occurred, and has since partially revegetated.  My pine cone source was a lone longleaf pine (P. palustris) growing on a grassy savanna-like area dotted with mature deciduous trees including cherries and oaks.  The cones lay on grass and herbs or needle litter, often in partial contact with very sandy soil.

A Site 2 cone
Female Heteroonops spinimanus from
Site 2
I tapped 20 fallen cones and collected 8 spiders from at least 4 families.  Only two specimens were mature, a male salticid that I haven't identified yet, and a female Heteroonops spinimanus (Oonopidae).  The latter was an especially interesting find for me, given that Florida is the the only place in the continental United States where the species is found.  The only other oonopiid I've ever collected was a male of the undescribed Orchestina sp. #1.  In 2011 I tapped it from ponderosa pine (P. ponderosa) cones near Lake Chelan in Washington state.

In addition to a fair number of spiders, the Site 2 cones held oodles of small cockroaches.  For once, spiders weren't the fastest runners in my net!

Site 3

Site 3 cone source: longleaf pine near
Site 3 cones
A small urban park surrounding the Lake Elbert public boat ramp was my third collecting site.  Note the glorious Southern live oak (Quercus virginiana) draped in Spanish moss (Tillandsia usneoides) in the background.  It dwarfed our car.  I could have sat and gazed at that gorgeous tree all day.

Half a dozen longleaf pines had dropped enough cones in unmowed lakeside grass or in or near planting boxes around their bases that I was easily able to find 50 cones to tap.

A spitting spider, Scytodes sp.
Interestingly, none of the cones I found lying in the unmowed grass contained any spiders.  The 9 spiders that I collected all came from the cones laying on oak leaf or pine needle litter next to or within the planter surrounding the base of the pine in the foreground of my photo.  This batch of spiders were a relatively diverse bunch from five families: a female linyphiid and a male and female salticid I haven't identified yet, as well as juveniles from the families Clubionidae, Theridiidae and...Scytodidae!  I hadn't seen a scytodid before.  They're called spitting spiders because, according to Ubick et al. (2005):
Scytodids are unique among spiders in capturing prey by spitting strands of glue from the fangs; hence the common name.  The glue is produced in an enlarged posterior lobe of the venom gland that occupies much of the prosoma and accounts for the convex carapace of the spider.  Prey is bound to the substrate and immobilized, from a distance of up to a few cm, by fine strands of glue with venom that are sprayed extremely rapidly (140 ms).

Male brown anole
Anole with cone
Also present in this planter were several brown anoles (Anolis sagrei), an invasive lizard native to Cuba and the Bahamas and established in Polk County since at least 1979.  Watching them dart after invertebrates, I wondered whether spiders and other animals that use fallen pine cones are better able to survive the depredations of the brown anole than are other species.

Wheeler and Stoops (2010) reported the presence of spiders in fallen longleaf pine cones in Alabama, Georgia, North Carolina and South Carolina.  This blog post is the first report that I am aware of that confirms the presence of spiders in fallen cones in Florida.

Literature Cited

Ubick, D., P. Pacquin, P.E. Cushing and V. Roth (eds). 2005. Spiders of North America: an identification manual. American Arachnological Scoiety, Keene (New Hampshire). 377 pages.

Wheeler, A.G., Jr. and C.A. Stoops. 2010. Cnemodus hirtipes Blatchley and C. mavortius (Say) (Hemiptera: Lygaeoidea: Rhyparochromidae) in fallen pine cones, with consideration of the biological significance of cone occupancy. Proceedings of the Entomological Society of Washington 112:155–168.

Ants carrying sand grains near Lake Elbert (Site 3)

American alligator (Alligator mississippiensis) near Site 2

Sun streaming through Spanish moss (not really moss, but a bromeliad!) on oak at Site 3

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