Surprise, surprise, surprise, yet another exotic invader has recently been discovered in the Sunshine State. When you have pythons, tegu lizards, and other alien animals roaming free and reproducing in the swamps, a tiny arachnid might seem to be no big deal. Still, it is symptomatic of greater problems in protecting our native ecology that extend beyond lax regulation of the pet trade. This particular species, Cithaeron praedonius, is native to the Old World, from western Africa (Gambia), to Greece, Libya, and Malaysia. It is an accidental introduction to Australia and Brazil (Carvalho, et al., 2007). The first report of this species in the U.S. came from Port Richey in Pasco County, Florida, in February, 2011.
The manner in which the Florida record was revealed reflects the importance of citizen scientists and the power of the internet. A member of the Arachnoboards online community posted images of a spider he had found and that he was having trouble identifying. He then enlisted the help of Florida arachnologist G.B. Edwards. The mystery was solved in part when another Arachnoboards member located in Italy suggested the species. Specimens subsequently sent to Edwards allowed him to confirm the identification conclusively (Edwards & Stiles, 2011).
Whether this was an isolated incident of introduction seems to have been answered with a “no,” as another record was reported this last week on Bugguide.net, another influential internet resource for identifying North American insects and other arthropods. The location this time is Winter Springs, a suburb of Orlando, in Seminole County, Florida.
Cithaeron praedonius is a spider that hunts “on foot,” rather than spinning a web and waiting for prey to be intercepted by the silken snare. In fact, this species may be a specialized predator of other spiders. Observations have shown that in the first Florida case, the live specimens in captivity readily fed on native cobweb weavers, as well as juvenile Brown Widow spiders. Given its nomadic nature, perhaps the species has already spread to neighboring counties from the Port Richey location.
The spider is clearly reproducing, as flat, round egg sacs were found at the Pasco County location. Spiders of different ages were also observed. Each spider creates a silken “nest” in which to molt, and perhaps rest when it is not actively hunting. Otherwise, the spider dispenses with silk in its daily life.
These are small spiders, mature females averaging about 5 millimeters in body length, males about 3 millimeters. The compact arrangement of the eyes might fool one into thinking they might be juvenile males of the Southern House Spider, Kukulcania hibernalis. Worse yet, they could be mistaken for young recluse spiders (Loxosceles sp.).
If you have seen Cithaeron praedonius, or any other unfamiliar spider, consider taking clear images and submitting them to Bugguide, or Project Noah, or another community where scientists and the public interact. Securing specimens and preserving them in ethyl alcohol, along with a label noting the date and location of capture (plus the collector’s name), is tremendously important in confirming identifications later.
Our invasive species have many points of origin and many avenues of access to new territories thanks to unregulated (free?) trade, our internationally mobile society, and our fascination with organisms both floral and faunal, from foreign soils. Perhaps we should be more satisfied with the life that lives here already, and how we can better protect it from exotic competition.
Sources: Carvalho, Leonardo S., Alexandre B. Bonaldo, and Antonio D. Brescovit. 2007. “The first record of the family Cithaeronidae (Araneae, Gnaphosoidea) to the new world,” Revista Brasileira de Zoologica 24(2): 512-514.
Edwards, G.B. and Joe T. Stiles. 2011. “The first North American records of the synanthropic spider Cithaeron praedonius O.P.-Cambridge (Araneae: Gnaphosoidea: Cithaeronidae), with notes on its biology,” Insecta Mundi 0187: 1-7.
I've actually already recorded them in neighboring Pinellas County, actually.
ReplyDeleteGlad to see people are still reading about this!
--Joe Stiles
Just killed one in my house in Alva, Lee County Fl
DeleteJust found one in my shower in Gainesville!
DeleteThis evening I found a spider almost identical to the one in this picture and pictures on line referring to this spider. Is this spider dangerous?
ReplyDeleteKristin: Many, many spiders superficially resemble this one, and it takes an expert to tell them apart (from actual specimens, not images). The spider species described above is not dangerously venomous to people or pets, but without seeing *your* spider I cannot reach a responsible conclusion.
DeleteHey i just bitten by this spider and I still have the spider in a bag
DeleteI was just been bitten by the spider 30 minutes ago is this spider dangerous do I need to go seek medical attention
DeleteJaron, I cannot help you. Please take the specimen with you if you need medical attention (though I doubt that is likely).
DeleteHello Eric,
ReplyDeleteFound your site while looking to see if the spider I had taken a picture of in Palm Beach County was a Brown Recluse. Unfortunately I did not capture it. It looks more like the spider you have pictures. I have some very good pictures I could provide.
I think I may have an infestation of these. I took a picture, although not a good one, but the spider was faster than I! How can I send the pic to you to see if you think this is the same species?
ReplyDeleteWhat would be a good way to send you pictures of a spider corpse I found?
ReplyDeleteIt is excruciatingly small (I imagine it's a juvenile) so I can't get a good look at it and my camera strains to get decent photos. I know it's unlikely to be a Brown recluse, but I'm a "be absolutely sure" kind of gal.
Also, I've been getting along with my cobweb family for years. I sometimes worry for their safety.
Hi, Flux! You can include images with any query to the "forum" section here (see tab at top of this page); or you can reach me on my "Bug Eric" Facebook page.
DeleteLooks like they could be the same species, but you should have mentioned that there is a spider here in Florida, called the Sac spider. I've seen them here (especially on automobiles) since the mid 90's for sure. It looks very much like this spider you've shown here. I'm sure you'll have dozens of freaked out Floridians confusing it with the spider you're referring too. The internet continues to dumb down large populations in huge waves of misinformation.
ReplyDeleteHoping you might be able to help me out. I live in Seminole Fl (Pinellas County) and have images of a dead spider. Sorry for the quality but I am scared to death of them and well it came close to getting on me and my dog. I have had multiple of what I believe are these same spiders mostly on my patio like the one I have images of but also have had them in my house (2 that I know of). At first I thought it was possibly a brown recluse but when I lightened up the image (this occurred at night and well my flash was not much help) to see if it could see a fiddle on its back. I didn’t but am still concerned. I ran into your page that was talking about Cithaeron praedonius and thought this was similar. I am only about an hour away from Port Richey. Any help would be much appreciated!
ReplyDeleteI have a spider right outside of my house that looks eerily identical. And I'm all the way in Portland, Oregon.
ReplyDeleteHave them in deltona Florida killed 4 so far this week in house.
ReplyDeleteyikes i found something that looked identical to this in my shower in ontario. except it was bright orange and behaves identically to everything ive seen on this issue. it is late january just like all other sightings. (Dec-Feb) is this dangerous?
ReplyDeleteYour spider is likely a different species. The only truly dangerous spiders in North America are widows (genus Latrodectus) and brown spiders (genus Loxosceles), both of which are loathe to bite anyway. Sleep soundly.
DeleteI found one in Panama City Florida about a month ago and mistaked it for a young Brown Recluse. Thank you for this site. Now I know what it was. I saw it while I was reading in bed, it was by the plug I was using to charge my phone. Fast little thing was running across my bedding and ran up my arm and got away. I bombed my home and found it. Again thank you for helping me identify the spider.
ReplyDeleteI live close to the Port Richey area and caught a very similar spider in my house and released it outside. I'll be more wary and document it if I find another one. I thought it looked bizarre and not like the typical spider pals around here.
ReplyDeleteI live in the same area(Port Richey) and think I found one of these in my house this morning.
DeleteNearly all spiders are *venomous*. That does not mean they are dangerous to people or pets. If you are a healthy human being the only spiders to concern yourself with in the U.S. are widows (Latrodectus spp.) and brown spiders (Loxosceles spp.), and even those rarely pose problems.
ReplyDelete