jumping spiders

Jeepers Creepers, where’d ya get those multilayered retinae?

/ Ted C. MacRae / 28 Comments

A few weeks ago I was fortunate to get a chance to blast down to the White River Hills in extreme southwestern Missouri.  Cicindela obsoleta vulturina (prairie tiger beetle) was my quarry – I had made arrangements to meet up with fellow cicindelophile Steve Spomer (principal author of Tiger Beetles of South Dakota & Nebraska, Spomer et al. 2008) and show him a few of the better sites I had found for this species.  We would have good success due to gorgeous fall weather and perfect timing, and the next day I would be fortunate to extend its known distribution further north and east.  Still, the beetles are not early risers, and I found myself that second morning with some time on my hands while waiting for these sleepy-heads to arise from their slumber and begin their foraging activities.  As I trolled the thinly soiled dolomite exposures of a new site I had identified the previous day, a spot of red jerking erratically through the sparse vegetation caught my eye, and looking closer I was delighted to see this small but brilliantly colored jumping spider (family Salticidae) trying to evade my gaze.

Jumping spiders are perhaps the most diverse of all spider families, but it is their extraordinary visual capabilities and complex predatory and courtship behaviors that they are best known for.  Popular as research subjects, to the rest of us they are simply endearing little animals.  Some of the largest and most colorful jumping spiders belong to the genus Phidippus, which is also one of the most diverse genera in the family and boasts some 60 species in the continental United States (Edwards 2004).  The genus is characterized by details of the eye placement and carapace shape (Richman 1978) but can often be recognized by their relatively large size, numerous erect hairs, and conspicuous iridescent chelicerae just below the front eyes.  The species can be quite difficult to identify, especially the females, but I feel reasonably confident that this individual is a male of the widespread species P. apacheanus.

I wasn’t always so confident – browsing images on BugGuide left me confused after finding images of P. apacheanus and P. cardinalis males that looked almost identical. However, further digging reveals P. apacheanus is characteristically a more intense red, while P. cardinalis is more orangey with lighter bristles which may appear silvery.  Also, P. cardinalis often displays makings on the abdomen – generally a light line running around the anterior part of the abdomen and sometimes tiny light spots on the dorsum – that are absent in P. apacheanus.  (This begs the question as to whether some of the BugGuide photos may be misidentified?)  Another Phidippus species that might be confused with P. apacheanus is P. clarus; however, that species has a black cephalothorax and bright abdominal markings.  According to Herschel Raney, P. apacheanus is most often seen in fall.

This was a very difficult subject to photograph.  He refused to come out in the open, preferring to duck and peek from behind whatever vegetation he could find.  Realizing that my desire to photograph him without any manipulation would be a lesson in futility, I used my finger to prod him towards and onto a small, flat, lichen-encrusted rock, where he would look at me with ever-increasing alarm and try to flee at the approach of the camera.  Lots of failed shots were discarded in the field before I finally got a few I thought I could live with (which, I think, are a decided improvement over my first jumping spider photos).  As I zoomed in for the closeups, I saw for the first time the shimmering of his multilayered retinae moving in the depths of his primary medial eyes.  The retina is the darkest part of the eye, thus, when the eye is at its darkest the spider is looking straight at you!

Photo Details: Canon 50D w/ MP-E 65mm 1-5X macro lens (ISO 100, 1/250 sec, f/13), Canon MT-24EX flash (1/8 ratio) w/ Sto-Fen + GFPuffer diffusers. Typical post-processing (levels, minor cropping, unsharp mask).

REFERENCES:

Edwards, G. B.  2004. Revision of the jumping spiders of the genus Phidippus (Araneae: Salticidae). Occasional Papers of the Florida State Collection of Arthropods 11:i-viii, 1-156, 350 figs.

Richman, D. B.  1978. Key to the jumping spider (salticid) genera of North America.  Peckhamia 1(5):77–81.

Spomer, S. M., M. L. Brust, D. C. Backlund and S. Weins.  2008. Tiger Beetles of South Dakota & Nebraska. University of Nebraska, Department of Entomology, Lincoln, 60 pp.

Copyright © Ted C. MacRae 2010

My first jumping spider

/ Ted C. MacRae / 32 Comments

As a long-time professional and avocational entomologist, I find beauty and fascination in all manner of joint-legged creatures. Of course, beauty is in the eye of the beholder, and most people don’t exactly share my passion for these animals. Sure, butterflies enjoy almost universal approval, but beetles are just too crunchy, flies too filthy, wasps too aggressive, and cockroaches… well, eww! Even crabs and lobsters, tasty as they are, just move too robotically to engender any feelings of affection. None of these groups, however, seem to be as universally reviled as spiders – scuttling blurs of leg and fur with beady little eyes, just waiting to launch a sneak attack with their venomous gnashers. Few other coin-sized animals can cause an otherwise lucid adult to run screaming from their bathroom with such terror.

Except jumping spiders! Jumping spiders (family Salticidae) possess many of the same traits that condemn other spiders to the ranks of the creepy – hair and venom and lots of eyes; yet they have other unique qualities that make them nevertheless endearing, almost cuddly, to all but the most ardent of arachnophobes. Their human-like “face” featuring two large, forward-facing eyes and inquisitive nature give them a charisma that almost invites interaction. Approach any other spider, and it scampers back into the nearest crevice. Jumping spiders, on the other hand, turn and face the intruder – you can almost see them sizing you up – perhaps even moving forward a little to have a better look. It makes them seem, well… intelligent. Add to that their stunning diversity (~5,000 species), dazzling colors, and the sometimes impressively elongated choppers of the males, and you’ve got the perfect recipe for charm. Bouncy, furry, smart, cute, and big bright eyes – almost sounds like a kitten!

The result of all this charm is that jumping spiders are wildly popular subjects for macrophotography. Accordingly, there has been a veritable explosion of online photographs of jumping spiders, dominated by close-ups of that irresistible face. These shots here represent my first attempt to photograph one of these endearing creatures, and while I’m happy with them considering my relative newness to the field, they are a far cry from the spectacular images being produced by some other photographers. Perhaps the best of these is Thomas Shahan, whose focus-stacked facial shots of these spiders are among the most stunning that you will find. Another photographer who has produced some excellent photographs of Malaysian jumping spiders is Kurt at Up Close with Nature. Perhaps someday my jumping spider photographs will be considered on par with those that these two gentlemen are producing – if that day comes, you can say it began right here!

I’m a beetle-man, so except for a brief attempt at ant taxonomy my area of expertise lies with the Coleoptera. Nevertheless, perusing the well-stocked archives at BugGuide leads me to believe that the individual I photographed is a subadult female in the genus Phidippus – perhaps something in the putnami species-group.  I found her on a lower branch of sweetgum (Liquidamber styraciflua) in a wet-mesic bottomland forest along the Black River in Missouri’s southeastern Ozarks feeding on a blow fly (family Calliphoridae).  While relatively drably-colored compared to many other species in the family, a glimpse of her bright blue-green chelicerae (fangs) can still be seen.  I tried to get her to drop her prey to get a better look at the fangs, but she wasn’t having anything to do with that – mealtime is mealtime!

Photo Details: Canon MP-E 65 mm 1-5X macro lens on Canon 50D, ISO 100, 1/250 sec, f/13-14, MT-24EX flash 1/8 power w/ Sto-Fen diffusers. Minimal cropping and post-processing.

Copyright © Ted C. MacRae 2010

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