Howdy, BugFans,
This small spider is in the Sheetweb spider family Linyphiidae, which we have met before in the form of the Splendid Dwarf spider Bug o’the week – Splendid Dwarf Spider – Riveredge Nature Center. In some parts of the world, sheetweb spiders are called Money spiders, because if you find one on your person, you’ll have good luck/good fortune. With about 4,200 species worldwide, Linyphiidae is the second largest spider family, after the Jumping spiders. Because of their small size, many sheetweb spiders escape both detection and investigation. They prey on small arthropods like aphids, flies, springtails, and their fellow spiders and, like many spiders, are considered useful biological control agents.
BOWL AND DOILY SPIDERS (Frontinella pyramitala) (formerly Linyphia communis) are one of only two species in their genus. There’s probably one near you – in his bugeric blog, entomologist Eric Eaton calls them “one of the most common and widespread spiders in North America.” The other species, Frontinella huachuca (pronounced “wa-chew’ ka,” like the mountains) only occurs in Arizona. They are found in grassy areas, along woody edges, and in suburbia, but they also live in piney woodlands and in black spruce/tamarack bogs, which is where the BugLady photographed these.
Females Type of Orb Weaver? – Frontinella pyramitela – BugGuide.Net (3 to 4 mm long with a 9 to 12 mm leg span) are larger than males Spider BG406 – Frontinella pyramitela – BugGuide.Net, but not by much Mating Spiders – Frontinella pyramitela – BugGuide.Net.
Full disclosure – the related Filmy dome spider (Neriene radiata)
Spider – Neriene radiata – BugGuide.Net looks very much like the Bowl and Doily spider but spins a dome web with no doily Filmy Dome Spider Neriene radiata I think – Neriene radiata – BugGuide.Net.
The name “Bowl and Doily” reflects the design of its web (one source felt the need to explain to its readers what a doily is, but the BugLady has faith in the BugFans). Neither the tangled vertical strands/trip lines of the bowl nor the horizontal silk of the doily is made of sticky silk, but debris like twigs, leaves and dust may get snagged in the web. The spider does not spin a new web, but cleans the old one.
She hangs below the doily, belly up, both for protection and ambush (there aren’t many pictures of the dorsal side of a Bowl and Doily spider). When prey arrives, often flying into the trip lines and falling onto the doily, she can see her prey before she bites through the web to paralyze it. She pulls it through the doily to wrap or eat itFrontinella pyramitela – Bowl and Doily Weaver – Frontinella pyramitela – BugGuide.Net. Researchers have found that if they remove prey from her web, the spider will search for it (the bigger the prey, the harder she’ll look), and that she’s not fooled by bits of previously-consumed meals.
The Bowl and Doily spider’s biography includes several other quirks besides the odd shape of its web. A web may hold, along with the web-spinning female, one or more male spiders, female and males – Frontinella pyramitela – BugGuide.Net, independent of reproduction. Males cohabit with females, stealing prey that she catches and stores, but one source suggested that she may find it more energy efficient to leave him alone than to evict him, even though he may be harvesting up to a third of what she caches.
“Gregarious” is a word that’s rarely applied to spiders, but not only do the webs often hold more than one spider, these spiders like to spin webs in the vicinity of other Bowl and Doily spiders, which puts potential mates closer at hand.
Bowl and Doily spiders court at the end of the spider season, in late summer and early fall. The courtship is elaborate, with pheromones released by the female and with lots of web vibrations initiated by both male and female, designed to attract her attention to the male while communicating to her that he is not prey. He determines whether she is a virgin via a signal that she can give only if she is one (she becomes less fertile after her second romance, and he’s looking for the best outcome for his genetic materials). If the answer is “yes,” the game is on. The BugLady is, once again, dancing around good old-fashioned biological terminology in deference to BugFans whose company IT filters are easily embarrassed.
Males spar over females and the longer a contest goes on, the more likely it is that one will be injured or even killed, especially if one is smaller. A paper published in the journal Animal Behavior titled“A game theoretical interpretation of male combat in the bowl and doily spider (Frontinella pyramitela)” applied Game Theory to clashes between male Bowl and Doily spiders based on a female’s perceived value to them. If they both value her equally (based on their assessments of her fertility), the fight goes on and the larger male generally wins, regardless of which male was already a resident in the web.
The female creates one or two egg sacs in fall, and the spiderlings hatch the following spring and balloon away to find a new home that has fewer of their siblings in it Spider Flight – Field Station. Larry Weber, in Spiders of the North Woods, says that the adults are “frequently found on the snow.”
Fun Facts about Bowl and Doily spiders: they may regulate their temperature by orienting themselves with the sun’s rays, and scientists suspect that this has reproductive advantages; but they’re not sure why the spiders’ circadian rhythms are 24 to 33 hours long, depending on the season.
The BugLady