22 January 2024

I once heard a fellow araneologist refer to the members of this genus as the "Tootsies" and have never gotten that out of my head. The Tootsies (maybe it's "Tutsies"), like other jumping spiders, rely on their acute vision to actively hunt prey during daytime hours. They are most likely to be found by using a sweep net in grasslands or shrubby habitats. Females measure up to 7.0mm while males may reach 5.5mm (Kaston, 1948).

There are four species of Tutelina found in Minnesota. T. elegans and T. similis are known from across the state and are eventually going to be found in all 87 counties (probably). T. harti is known from across the state too but is less likely to be found in the boreal forests of northern Minnesota. Lastly, T. formicaria is a state-threatened species only known from a couple of locations in Anoka County.

T. elegans (Thick-spined Jumper) and T. similis (Thin-spined Jumper) are fairly common in prairies, shrublands, bogs and other open habitats. These two species are very similar to one another but can be easily distinguished in most cases by looking at a couple of field-marks. Adult females of the two species are often metallic green to copper to purple on their bodies due to small irridescent scales (though juveniles and some adult T. similis can sometimes be grayish). Both species have white stripes running down the legs and thin white lateral edges on their carapace. The female T. elegans has a white band on the anterior of the abdomen that T. similis females lack. There are a few individuals where this band is indistinct and are best left identified to genus; this can particularly be the case with subadults. A female T. elegans: https://www.inaturalist.org/observations/83247798. A female T. similis: https://www.inaturalist.org/observations/123262523.

A close look at the males of these two species will reveal spectacular "Groucho" eyebrows (see https://bugguide.net/node/view/189639). Males can be gray to green-gray or tan but do not typically show the metallic sheen of the ladies. They are best distinguished from one another by the presence/absence of a brush of black hairs on the first pair of the legs. Male T. elegans have it: https://www.inaturalist.org/observations/189379923. Male T. similis do not: https://www.inaturalist.org/observations/5141766.

T. harti, or Hart's Jumper, is more often found in oak savannah-like habitats or cottonwood groves rather than wide open spaces. While I find them sweeping occasionally, they are more likely to be seen crawling on tree trunks with rough bark. In this species, the males are the metallic ones (blackish) and have a thick first pair of legs, each possessing a thick black brush of hairs on the tibia. The carapace often has a thick white leading edge and distinct thin, white lateral edges. Females are more nondescript (sometimes with metallic scales) but are also patterned in black and white (the flattened carapace can be a helpful hint to its identity). The abdomen is mostly white with black patches but the white scales can be rubbed off and thus abdomen pattern is variable. A male: https://www.inaturalist.org/observations/5139336 and a female: https://www.inaturalist.org/observations/6659067.

T. formicaria is a convincing ant-mimic, more so than the other members of the genus . Sexes are similar and the body can be brown to black overall. The legs have white stripes similar to other members of the genus and the white lateral edges of the carapace can curve around to the posterior as well. This species is rarely encountered across its range in eastern North America but it has also been suggested that an ant-like jumper living in the company of ants may just be more easily overlooked. They often wave their first pair of legs in the air which makes them look more like antennae than legs. One of the rare images of this species from Minnesota: https://www.inaturalist.org/observations/58075769. Also, Dick Walton has taken some excellent footage that shows how ant-like this species behaves: https://www.rkwalton.com/salticids/Tutelina_formicaria.php.

References:
Kaston, B. J. 1948. Spiders of Connecticut. Bulletin of the Connecticut State Geological and Natural History Survey 70: 1-874.