What makes for a good spider photo ID? Here are a few tips that will help if you’re thinking of sending a photo to any type of social media group, nature app, or your friendly neighborhood “spiderologist”. Identifying spiders to species by looking at a photo is very tricky and not as easy as you’d think! There are seventy-one families of spiders in North America (probably more now). Identification to the taxonomic family level is possible via photos. Getting more specific usually requires a dissecting scope and a good manual, but knowing a spider’s family can provide you with an abundance of information without having to get specific. There are many spider enthusiasts willing to help if we are able to see some key features.
A clear, close up shot of the eyes. This does mean you have to get close to the spider and maybe bust out your awesome camera macro setting! You’ll never have to worry about the spiders blinking. The issue will be getting them to stay put long enough because, yes, you are a very large possible predator who makes a lot of vibrations! The number of eyes and their arrangement can determine what family (or even genus) the spider belongs to. Here are some examples of close up portraits. Proper lighting is essential and in most cases, I’ve had to catch the spider to be able to get these shots. Of course, catching the spider is totally optional, but you might get a better picture! Remember, most of the spiders you’re going to encounter are completely harmless! And the ones that are medically significant do not readily bite unless they are being actively squashed against your skin!
Was it in a web? Not all spiders spin trapping webs, some hunt by prowling or ambush. Mentioning whether your spider was in a web or not can be a clue. If it was in a web, noting the structure or shape of the web is helpful, although not always foolproof. You might find a male spider that would normally be associated with a web wandering in search of a mate.
Where was the spider found? Definitely mention where you are, city and state. This helps the identifier exclude certain types of spiders. For example, in the lovely city of Pittsburgh, we are too far north to have the pleasure of seeing goldensilk orbweavers when we go hiking and the west coast doesn’t get to see the spiky awesomeness of an Arrowshaped micrathena when they go hiking. The brown recluse is often claimed to have been found in areas out of their natural range which is probably more likely the mis-identification of a native spider. Location is important! On many spider ID platforms, location is a required field for submission. Getting specific about exactly where you found your spider doesn’t hurt either, like in your garage or garden. Read Spider Real Estate for some interesting spider venues.
How big is it? “Big” can be subjective depending on one’s comfort level around spiders or one’s appetite for drama. Again, you may need to get close to get your best guess. Not everyone carries a ruler around with them (ahem), or wants to hold spider in their hand, so a familiar object like a lighter, coin, or a pencil in the pic will help if it’s practical. Spiders are officially measured from their head to the end of their butts, legs are not included, so that’s something to keep in mind. The leg span of a cellar spider is larger than the leg span of the much heavier-bodied wolf spider so “coin sizes” can be deceiving without a picture.
Spinnerets. The spinnerets are where the spider dispenses its silk. Located at the end of the abdomen, most spiders have three pairs of spinnerets. There are a few families that only have two pairs. The spinnerets can be shaped like little exhaust pipes consistent in the Gnaphosidae family or in a horizontal row characteristic of the Hahniidae family. There is a spider that’s only found in southern Texas and southern Florida called the Longspinneret spider. Its spinnerets are actually longer than its body making this a one-and-done distinguishable ID characteristic.
Notice the standouts. If the spider was faster than your camera and you missed the shot, what did you immediately notice about the spider? Was it hopping? Was it brightly colored? Did it have a weird shape? When I’m stumped on an ID, I follow any leads based on a stand out. I’ve done google searches for “spider with yellow shoulders” before and got nothing back except for shoulder tattoos of spiders with yellow in them, but doing an internet search might get you on the right track.
Okay, so now that you have a better idea of what can help you get an ID, here are some sites (definitely not all of them) where someone will be happy to take a look at your pics and get back to you with an ID or at least an educated guess.
I hope these suggestions are helpful! Any interest in spiders is supported and encouraged, even if you only have a blurry photo from a distance. If you are curious enough to want to know what kind of spider you have, there is a passionate community waiting to help you! Happy “spidering”!
Resources and references:
Bradley, Richard. Common Spiders of North America. Berkeley, CA: University of California Press; 2013.
Common Names of Arachnids 2003 Fifth Edition – The American Arachnological Society; Committee on Common Names of Arachnids
Foelix, Rainer F. Spider Biology, third ed. New York, New York: Oxford University Press; 2011.
Ubick, D., Paquin, P., Cushing, P.E. and Roth, V. (eds). 2017. Spiders of North America: an identification manual, 2nd Edition. American Arachnological Society, Keene, New Hampshire, USA.
World Spider Catalog (2020). World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 21.5, accessed August, 28, 2020.