Bug Eric: Spider Sunday: Star-bellied Orbweaver, Acanthepeira stellata

NOTE:Right now’s submit is an replace of a earlier submit on November 11, 2012, prompted by a stunning current discover in our personal again yard, on June 22, right here in Leavenworth, Kansas, USA. I habitually tour our property in search of bugs, spiders, and different invertebrates, and nearly dismissed a brown, thorn-studded object as a chunk of plant particles that had turn out to be adhered to our siding. Fortuitously, I had seen different particular person Star-bellied Orbweavers beforehand, although none of them practically as massive as this one.The laborious, spiked stomach of this grownup feminine was practically the scale of a dime.

Nothing to see right here….Psst, she’s going through southeast

There isn’t any scarcity of the bizarre within the spider world, and this animal is a surprising instance. Certainly one of my mates on the photo-sharing web site Flickr requested “Why is it ‘star-bellied’ when it is star-butted? Is there extra star-ness on its stomach?” Truthful query, to which I’ve no reply. Possibly the person who first noticed one described it from the ventral aspect. The sharp tubercles definitely present up from all angles. The spikes improve its camouflage because it passes itself off as a bur, seed pod, or little bit of dried vegetation.

She has legs!

Acanthepeira stellata is considered one of 4 North American species within the genus, collectively discovered from southeast Canada south and west to southern California. This species particularly is thought from southeast Canada to Florida, and west to Kansas and Arizona.

An immature spider in its internet in western Massachusetts

These are usually not massive spiders. Mature females measure 7-15 millimeters in physique size, males 5-8 millimeters. Their distinctive look could make them simple to determine, however fairly troublesome to search out, until they’re sitting within the hub of their internet, which they do not appear to do with reliable regularity. Couple their cryptic form with the truth that they have an inclination to construct their round snares lower than three ft off the bottom in prairies, fields, meadows, and forest openings, and it may be an train in futility to hunt them amid tall grasses. Ought to one degtect your method, it would drop to the bottom, fein dying, and disappear within the tangle of vegetation.

Can you notice the spider at Thoh-Dah Prairie in Missouri?

Star-bellied spiderlings emerge from egg sacs in summer time, and overwinter as immature or penultimate (one molt faraway from maturity) people. Grownup females could be discovered from Could to October, not less than in Illinois (Moulder, 1992). Mature males could be seen from Could to September. I’ve discovered near-adults in odd locations, in all probability on account of “ballooning.” Ballooning is a dispersal technique utilized by many younger spiders to journey afar and stake out their very own territories. A spiderling sometimes climbs as much as the summit of a tall object, stands on tiptoe (“tip tarsus??”), and points lengthy strands of silk from its spinnerets. These threads are caught by the wind, and when the spider lets go it could be blown tons of of ft, if not a mile or extra. One child A. stellata was captured at 1000 ft within the air over Tallulah, Louisiana, on December 13, 1930 (Fitch, 1963).

This baby has ballooned onto the seaside at Cape Could, New Jersey

As soon as settled, these spiders spin the attribute orb internet to snare bugs, principally immature grasshoppers. There’s one file of an grownup feminine preaying upon an American Inexperienced Tree Frog, Hyla cinerea, however that is definitely not a routine occasion (Lockley, 1990).

An grownup at evening in Damaged Bow, Oklahoma

Star-bellied Orbweaver will not be resistant to predators itself. The Black and Yellow Mud Dauber, Sceliphron caementarium, is a parasitoid wasp that stings spiders into paralysis and stockpiles them in mud cells as meals for a single larval wasp in every cell. The wasps are undeterred by a hard-bodied spider.

Subadult spider in its internet at evening in Adams County, Ohio

You might have higher luck discovering the Star-bellied Orbweaver at evening. Many species of orbweavers which can be in hiding by day transfer to the hub (middle) of their webs after darkish. Taking an evening hike reveals one other world anyway, nocturnal spiders being among the many spectacular highlights.

Sources: Guarisco, Hank. 2017. A Pocket Information to Frequent Kansas Spiders. Wichita, Kansas: Nice Plains Nature Middle. 67 pp.
Fitch, Henry S. 1963. Spiders of the College of Kansas Pure Historical past Reservation and Rockefeller Experimental Tract. Lawrence, Kansas: College of Kansas Museum of Pure Historical past, Misc. Publ. nol 33. 202 pp.
Gaddy, L.L. 2009. Spiders of the Carolinas. Duluth, Minnesota: Kollath+Stensaas Publishing. 208 pp.
Lockley, T.C. 1990. “Predation on the inexperienced treefrog by the star-bellied orb weaver, Acanthepeira stellata (Araneae: Araneidae),” J. Arachnol. 18(3): 359.
Moulder, Bennett. 1992. A Information to the Frequent Spiders of Illinois. Springfield, Illinois: Illinois State Museum Fashionable Science Sequence, vol. X. 125 pp.
Weber, Larry. 2003. Spiders of the North Weoods. Duluth, Minnesota: Kollath+Stensaas Publishing. 205 pp.