Greetings, BugFans,

The BugLady encountered this distinctive wolf spider (family Lycosidae) recently at Spruce Lake Bog, and then discovered some earlier shots of it from Riveredge in her “X-Files.” She figured that the furry-legged spider was in the genus Schizocosa. One source says that they look like they’re wearing leg-warmers. Some species in the genus have and some don’t, and in those species that do, only the males have them. BugFan Mike suggested that it might possibly be the very common Schizocosa ocreata, the Brush-legged wolf spider. The BLWS has apparently been adopted by researchers, and there’s lots information about it online!  

This spider is found on the ground in forests, forest edges, and grassland edges, where its longitudinal stripe camouflages it on leaf litter when (as long as it’s sitting still). But research shows that when viewed from the side at ground level, the spiders contrast with their background rather than blending in, and so are easily seen by potential mates, especially when a male is waving his brushy limbs.  are about one-fifth to one-quarter of an inch long (excluding legs), and males are slightly smaller. They have great eyesight but no ears, though they have sensory organs in their legs that pick up vibrations.  

Wolf spiders don’t spin trap webs—they wander around ambushing other wolf spiders and small insects like crickets and springtails that they encounter on the ground, running out to capture them (like a wolf).  They bite and immobilize small prey right away, but they envelop larger prey with their legs before biting them.  Research shows that if a hunting spot proves to be unproductive, a BLWS will move to a different spot. They are preyed on by visual hunters like toads and birds. Spiders make up a huge proportion of the food that parent birds bring to their nestlings because spiders are rich in taurine, which is vital to brain development. 

Wolf spiders don’t spin trap webs, so females are not waiting coyly in place for males to find them, but females do spin a pheromone-laced dragline that extends behind them as they move across the landscape. The dragline communicates, to any interested male that comes across it, her age, reproductive status, and even if she has cannibalized another spider recently. (One study suggests that the male can detect that a female has passed, and he can follow her scent trail, but he can’t tell which direction she was going.)  He prefers well-fed virgins; she prefers larger males with bushier legs. Just sayin.’

Females communicate chemically, and males communicate visually by bouncing around and waving their legs vigorously. (OK, they’ve earned the nickname “the twerking spider.”) Males also communicate audibly/seismically by vibrating body parts against each other (stridulation) or against nearby objects or the substrate.  

As always, spider courtship has its hazards. Female BLWSs, especially almost-mature and recently-molted females, commonly attempt to eat their suitors (sexual cannibalism). Smaller males with smaller leg tufts are cannibalized more frequently than larger males with larger leg tufts.  Some species of male spiders bite reluctant females, and some bite and wrap females to immobilize them so they can make a safe getaway after the fact.* As researchers at the University of Cincinnati wrote, “antagonistic coevolution between the sexes often results in a complex arms race between male persistence and female resistance.” Male BLWSs may bite back if attacked, even though it may negatively affect their reproductive success. 

Female wolf spiders and raised so it doesn’t drag on the ground, controlling the temperature in the sac by moving into and out of the sunlight. (Nursery web spiders carry their egg sacs up front, in their jaws.) Her for a week or two until they can take care of themselves. The spiderlings overwinter as sub-adults and mature in spring and may live for a couple of years.  

BLWSs react differently to wet and dry leaves. Whether they are displaying for a potential mate or just hunting, movement makes them conspicuous on the forest floor. One study showed that the call of a nearby Blue Jay causes them to “freeze” in place. Because vibrations travel effectively through dry leaves but are “muffled” by wet ones, they will freeze longer on dry leaves. Like the signals of Blue Jays, the courtship vibrations of male BLWSs travel better through dry leaves, so they resort to more leg-waving in wet weather.  For the female, vibrations are a big part of the sales pitch, so male courtship isn’t as successful when leaves are damp.  

Fun Facts About Brush-Legged Wolf Spiders

• They are known to prey on Black-legged/Deer ticks, which spread Lyme disease, effectively reducing tick populations in limited, outdoor experiments. 
• It’s common for a BLWS to self-amputate and regenerate damaged limbs, but the regeneration process necessitates an extra few days between molts. 

In love with wolf spiders? called “Biologists say wolf spiders have a wider range of personality than once believed.”   

The BugLady

*The BugLady has to be delicate about describing reproductive activities, because the filters of some servers and IT squads (some BugFans read BOTW where they work) bounce back anything they think is racy (like normal, biological terminology).  

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Greetings, BugFans,

One afternoon in late June as the BugLady was walking along the cordwalk at Kohler-Andrae State Park, she noticed a few half-inch-ish holes in the sand, holes that had more “structure” than the ones she makes with her walking stick, and larger than those made by solitary wasps. She took a couple of throwaway shots and was very surprised when she put one up on the monitor and noticed eyes and legs! She photographed more holes on subsequent trips, but their openings were unoccupied. The cordwalk goes over both dunes with loose sand, and areas with low vegetation and a somewhat more organic soil. The holes were in the loose sand. 

She asked BugFan Mike if it might be a wolf spider called the Burrowing Wolf Spider (Geolycosa missouriensis). He said that was a possibility and urged her (as always) to be conservative in her spider IDs, especially considering the quality of the picture. Amen, Mike! 

Wolf spiders (family Lycosidae) (lycosa is Greek for “wolf”) are common, hairy, nocturnal, ground-dwelling hunters with very good eyesight. Most species of wolf spider do not spin trap webs. 

[Quick Detour: nowadays, we use the name “” to refer to a group of non-Lycosid, palm-sized, hairy, tropical spiders. The BugLady’s 4^th grade teacher told a story of being in basic training in California and digging foxholes that bisected tarantula borrows, which she thought was pretty cool (she doesn’t remember much else of 4^th grade). Anyway, the original tarantula is a southern European/Italian wolf spider. Legend had it that if one bites you, you‘re doomed to dance a dance called the tarantella. The BugLady assumes that when they saw the big hairy spiders, those settlers from the Old Country applied the name of a scary spider that they already knew about. And in fact, a number of other groups of large spiders have been called tarantulas, too].

Wolf spiders in the genus Geolycosa are called the Burrowing wolf spiders (geo means “earth”). They live in vertical burrows, and they are habitat specialists, preferring loose, sandy soil that makes digging easier. Of the 75 species in the genus worldwide, 18 live in North America north of the Rio Grande. They have strong legs and (short spider anatomy review, here) two strong chelicerae (jaws) that are used as pincers and that are tipped with fangs. A , which look like a short leg on each side of the chelicerae, are used to manipulate food. 

Burrowing wolf spiders are generally Stay-at-Homes – the spiderlings don’t scatter far from the maternal burrow. They initiate their own lair when they’re very small, enlarging it as they grow, rarely straying more than an inch or so away from it, and retreating into it when alarmed. Populations remain fairly restricted. 

They are tied to one spot, with fixed pools of prey and of potential mates, but the trade-off is an absence of Flying Monkeys.They can dodge predators and avoid desiccation within a relatively stable, climate-controlled tunnel. In early fall, though, when a young spider’s fancy turn to love, he abandons that security and sets off in search of romance. They mate in late summer, but the gravid female doesn’t make an egg sac until the next spring. She displays – carrying around first her egg sac, and later her young��(and not eating them). Spiderlings hatch in early summer, overwinter as immature spiders in their first year, and become adults in late summer of their second year.

Gratuitous vocabulary word(s) of the day: some Geolycosa species are “turricolous” (they live in areas that have some leaf litter, and they create little turrets or lips made of debris, sand, and silk around the ), and others are “aturricolous” (they don’t). 

Bracing itself within the tunnel with its legs, the spider uses its fangs to loosen the sand, and if the sand is not moist enough on its own, it uses silk to compact the sand into a pellet. It uses its chelicerae and palps to move the pellet to the opening of the burrow, and it disposes of the pellet by flicking it away (sometimes a foot away) with its forelegs – unless it’s going to use it to build a turret. Burrowing wolf spiders reinforce the upper section of their lair by covering the walls with a few layers of silk. Summer burrows are less than a foot long, but winter burrows may be more than five feet deep. Researchers who studied Geolycosa missouriensis noted that a spider excavating an average burrow removed 918 sand pellets. 

Larry Weber, in Spiders of the North Woods, says that if you stick a grass stem down an occupied Geolycosa missouriensis burrow, the spider will grab it and hang on, and you can dig out the entrance and see the spider. Seriously, Larry?  All that work – 918 pellets – why would you?

They ambush their prey – lurking in the entryway and darting out to grab nocturnal invertebrates like crickets as they wander by. They feed within, and the indigestible bits of prey fall to the end of the tunnel. About the Geolycosa, the publication “The Insects and Arachnids of Canada, Part 17,” notes that when kept in captivity, “They should be individually caged because they are fierce predators, and cannibalism can soon reduce the culture to a single well-fed individual.”

So – who was in that burrow? Here are a few possibilities.

A BURROWING WOLF SPIDER (), aka the Missouri Earth Spider or the Missouri Wolf Spider, is found on sandy loam soils from Texas to Ontario and Saskatchewan. Its leg-spread is around 1 ½”. 

The gravid female uses sand and silk to fashion a door for the tunnel in winter. She will bring her egg case into the sun at the burrow opening on warm, spring days, and females can be found in their burrows carrying young on their back in early summer. Sources are ambivalent about whether Geolycosa missouriensis makes turrets.  

GEOLYCOSA WRIGHTII��() It’s not as common, and its range is restricted to sand dunes and beaches from Indiana and Illinois north through the Western Great Lakes states and provinces. Females protect their newly-hatched offspring by sealing themselves into the tunnel with their young for a few days, until they find their feet. Geolycosa wrightii doesn’t make a turret. 

The BEACH WOLF SPIDER��() also makes silk-lined tunnels, but unlike the Geolycosa, it hunts at night by chasing after prey on beaches and wetland banks, and shelters in tunnels or under driftwood in the day. Entomologist Eric Eaton says that if you’re abroad on the beach at night, wearing a headlamp, “When the beam of the light hits a wolf spider, the animal’s eyes will glint a blueish-green shine…..and a female with young on her back looks like a diamond-studded stone.” 

The BugLady

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