Tutelina formicaria (Emerton, 1891)
A Jumping Spider
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Basis for Listing
Although Tutelina formicaria (a species of jumping spider) occurs in localized areas in Minnesota, Michigan, and several eastern states, it is not considered common in any of these areas. In Minnesota, the species has only been collected from two sites in Anoka County (Anoka Sand Plain Subsection). These sites are both located in areas of rapid suburbanization. Given its limited distribution in the state and very specific habitat requirements, Tutelina formicaria was listed as a special concern species in Minnesota in 1996.
Jumping spiders are one of the most recognizable types of spider as they generally have a stout body, rather short legs, a very large set of eyes, and the ability to jump. Their body shapes and colors often imitate prey such as ants and beetles. Tutelina formicaria is up to 1 cm (0.4 in.) long and is ant-like in appearance. It is black to iridescent, has white edging along the sides of its head (cephalothorax), and white stripes on its legs. Even under 60x microscope, this species is difficult to differentiate from other Tutelina species that are much more commonly collected and occur throughout Minnesota. Maddison (2015) has grouped Tutelina with Paradamoetas, Pelegrina, Phidippus, and Sassacus genera, which include six state special concern species.
In Minnesota, T. formicaria occurs in oak savanna and sand prairie habitats. The presence of Penstemon grandiflorus (large-flowered beard tongue) appears to be important as old seed pods are used as sites for building retreats and making egg sacs (Cutler 1995). Habitat requirements in other states where the species occurs are not clear, but it has been collected from an overgrown mine dump and a deciduous woodland.
Biology / Life History
Jumping spiders do not spin webs for catching prey. Instead, they use silk to construct small tent-like silken retreats under rocks or logs or on plants, which they use at night and during hibernation. The females also lay their eggs in them. Jumping spiders are most active during the day, and they prefer sunshine. They tend to stay in their retreats on cloudy or rainy days. Jumping spiders are generally interested in whatever approaches them and will often turn and face human observers and may even advance towards them. They are harmless to people.
Jumping spiders have four pairs of eyes with the large principal pair giving them better vision than other spiders. The forward-looking placement of this pair of eyes provides binocular vision enabling them to judge distances accurately; they are able to identify prey, predators, and mates from up to 30 cm (1 ft.) away (Weber 2002). Physiological and behavioral experiments have demonstrated that they have color vision possibly extending into the ultraviolet range.
Jumping spiders feed primarily on insects, though some feed on other spiders. They will even feed on other jumping spiders usually those that are smaller than themselves. Jumping spiders actively stalk their prey instead of snaring it in a web. They may, however, steal insects snared by the webs of other spiders. Jumping spiders hunt primarily during the day using their keen eyesight to find prey. Having spotted their quarry, a jumping spider will slowly stalk the prey until it is within jumping distance. Then it lifts its front legs and pounces. Like all spiders, jumping spiders move their legs not by muscular contractions but by changing the pressure of the fluid within them. This hydraulic system enables them to jump up to several times their body length without having large muscular legs. Before jumping, the spider always affixes a silk safety line to whatever it is jumping from; in case it falls, it can climb back up this tether.
The same visual capabilities that are critical to jumping spiders’ success as hunters also support complex courtship behaviors. Males often differ in appearance from females and can have colorful, sometimes iridescent, modifications to their bodies, front legs, or mouthparts. The parts of the male's body that are used in courtship are often conspicuously colored. In many jumping spiders, the males perform courtship dances in front of the female that are species specific. The male's movements range from a slight lifting of a leg to complex movements such as bobbing their bodies, twitching their abdomen, performing zig-zag movements, waving their front legs, or flashing their mouthparts into the eyes of the females. Some male jumping spiders also have auditory signals that, when amplified, sound like buzzes or drum rolls. It is presumed that females choose mates based on their courtship dances. After mating, females lay their eggs in their silken retreat and often guard their eggs and newly hatched young.
Conservation / Management
Both known locations of T. formicaria in Minnesota are afforded some level of protection: Helen Allison Savanna Scientific and Natural Area (SNA), where it is believed to have persistent populations, and Cedar Creek Ecosystem Science Reserve. Maintenance of the current habitat at these two localities is vital for the survival of T. formicaria in Minnesota. Management of the areas by fire must take into account the fact that old P. grandiflorus seed pods may play an important role in providing shelter for this species. A systematic survey of P. grandiflorus may lead to the discovery of new occurrences of T. formicaria in Minnesota.
Although remnants of natural areas may often be too small or isolated to maintain the viability of some rare vertebrates, they may be suitable for maintaining invertebrates. Each new locality for a species adds to the suite of management options for their conservation and can even guide new land designations or acquisitions. Benign to humans, diverse, colorful, and behaviorally complex jumping spiders may be good ambassadors for their kin and invertebrates in general.
Best Time to Search
The best time of year to survey for this species is from June through September. Future surveys may want to employ alternative sampling techniques to sweep netting such as hand searches and leaf litter collection.
Conservation Efforts in Minnesota
Although sand prairie was frequently sampled in 1996, 1999, and 2001 for T. formicaria (Ehmann and Boyd 1997; Ehmann 2002), the species remains known from only the two Anoka County locations, which represent the western edge of the species' range (Cutler 1988). The most recent record is from 2001 from Allison Savanna SNA (Ehmann, 2002). Any new records will be of very high interest.
References and Additional Information
Cutler, B. 1988. Final report to the Invertebrate Group Committee. Pages 423-431 in B. Coffin and L. Pfannmuller, editors. Minnesota's endangered flora and fauna. University of Minnesota Press, St. Paul, Minnesota.
Cutler, B. 1995. Jumping spiders. Pages 108-116 in Statement of need and reasonableness in the matter of proposed amendment of Minnesota Rules, Chapter 6134: endangered and threatened Species. Minnesota Department of Natural Resources, St. Paul, Minnesota.
Cutler, B. In preparation. Spiders associated with old seed pods of Penstemon grandiflorus.
Ehmann, W. J. 2002. Conservation biology of special concern jumping spiders (Araneae: Salticidae) of Minnesota. Final Report submitted to the Natural Heritage and Nongame Research Program, Minnesota Department of Natural Resources. 11 pp.
Ehmann, W. J., and B. E. Boyd. 1997. Surveys for proposed special concern jumping spiders of Minnesota. Final report submitted to the Minnesota Department of Natural Resources. 18pp.
Foelix, R. F. 1996. Biology of spiders. Second edition. Oxford University Press, New York, New York. 336 pp.
Forster, L. M., and M. R. Forster. 1999. How do jumping spiders catch up on their prey?: a model for pursuit behaviour. (Araneae; Salticidae). Preliminary Draft, 06 Aug 1999.
Katson, B. J. 1981. Spiders of Connecticut. Revised edition. State Geological and Natural History Survey of Connecticut Bulletin 70. 1020 pp.
Maddison, W. 1994. Jumping spiders of America north of Mexico [web application]. Tree of Life web project, University of British Columbia, Vancouver, Canada. <http://tolweb.org/accessory/Jump>. Accessed 16 Aug 2006.
Maddison, W. P. 2015. A phylogenetic classification of jumping spiders (Araneae: Salticidae) Journal of Arachnology 43:231-292.
Newton, B., R. Bessin, B. Wallin, and P. Dillon. 2006. Kentucky critter files: insects, spiders, and their relatives.
Richman, D. B., and B. Cutler. 1978. A list of the jumping spiders (Araneae: Salticidae) of the United States and Canada. Peckhamia 1(5):82-110.
Weber, L. 2002. Spiders of the North Woods (North Woods naturalist guides). Kollath-Stensaas Publishing, Duluth, Minnesota. 216 pp.
Wikipedia contributors. 2010. Jumping spider. Wikipedia, The Free Encyclopedia. <http://en.wikipedia.org/wiki/Jumping_spider>. Accessed 15 April 2010.
Wovcha, D. S., B. C. Delaney, and G. E. Nordquist. 1995. Minnesota's St. Croix River Valley and Anoka Sandplain:a guide to native habitats. University of Minnesota Press, Minneapolis. 248 pp.