- Joined
- Feb 9, 2004
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- 1,763
Just found this guy trapped in my kitchen sink this afternoon and thought I'd get a pic or two to show how to ID this spider. This isn't a great pic though. I had to use flash and, well, it just doesn't look good. Short on time. I'll try to get better ones tonight when I get home.
First, when you see a spider that "looks like a recluse", look at the basic build, coloration, and pattern. You should notice that there is absolutely NO pattern on the abdomen. On very well-fed or gravid females you can sometimes see the "heart" of the spider on the dorsal abdomen but it's not very obvious from a distance. There should be a dark violin shape on the light, brown carapace that extends from the clypeus all the way to the posterior edge of the carapace. Rarely the mark will be faded or absent (I've never seen a recluse without the violin but it's possible.). The neck of the violin will be on the posterior portion of the carapace. The abdomen and legs are generally a darker brown than the carapace but can be almost grayish in color. There is no dimorphism in color between males and females. The legspan of both sexes is usually smaller than or about the same size as an American quarter/$0.25 coin. Males are generally "leggier" than females and have very prominent palpal bulbs.
Second, if you wish to get up close and personal with the spider and a more positive ID, look at the eyes. This is the best way to positively ID Loxosceles spp. Loxosceles spp. have six eyes in three diads. The flash blew out the anterior eyes in my picture but you can see the lateral eyes. Just imagine an identical pair where the big, bright light is on the spider.
All three diads are located inside the bottom third of the violin marking. The violin marking on the carapace and presence of only six eyes is constant in all species of Loxosceles spiders in the US. Just remember that the violin may be light in color and not as obvious.
The legs and body of this spider are covered in short, fine setae. They lack long setae and spines.
There are other spiders with six eyes (other Sicariidae, Dysderidae, some Pholcidae, among others) but they look different enough that confusion with recluse spiders should not be a problem. There are also spiders with what appears to be a violin marking that are often confused with recluse spiders but a more detailed inspection of color, habitus, and eye count and pattern will rule them out.
I'll try for better photos that will include a scale for size tonight and post tomorrow. If any of the info included here is inaccurate or just plain wrong please correct me.
First, when you see a spider that "looks like a recluse", look at the basic build, coloration, and pattern. You should notice that there is absolutely NO pattern on the abdomen. On very well-fed or gravid females you can sometimes see the "heart" of the spider on the dorsal abdomen but it's not very obvious from a distance. There should be a dark violin shape on the light, brown carapace that extends from the clypeus all the way to the posterior edge of the carapace. Rarely the mark will be faded or absent (I've never seen a recluse without the violin but it's possible.). The neck of the violin will be on the posterior portion of the carapace. The abdomen and legs are generally a darker brown than the carapace but can be almost grayish in color. There is no dimorphism in color between males and females. The legspan of both sexes is usually smaller than or about the same size as an American quarter/$0.25 coin. Males are generally "leggier" than females and have very prominent palpal bulbs.
Second, if you wish to get up close and personal with the spider and a more positive ID, look at the eyes. This is the best way to positively ID Loxosceles spp. Loxosceles spp. have six eyes in three diads. The flash blew out the anterior eyes in my picture but you can see the lateral eyes. Just imagine an identical pair where the big, bright light is on the spider.
All three diads are located inside the bottom third of the violin marking. The violin marking on the carapace and presence of only six eyes is constant in all species of Loxosceles spiders in the US. Just remember that the violin may be light in color and not as obvious.The legs and body of this spider are covered in short, fine setae. They lack long setae and spines.
There are other spiders with six eyes (other Sicariidae, Dysderidae, some Pholcidae, among others) but they look different enough that confusion with recluse spiders should not be a problem. There are also spiders with what appears to be a violin marking that are often confused with recluse spiders but a more detailed inspection of color, habitus, and eye count and pattern will rule them out.
I'll try for better photos that will include a scale for size tonight and post tomorrow. If any of the info included here is inaccurate or just plain wrong please correct me.
