The spider family Uloboridae (hackled orbweb weavers) includes 268 described species (Platnick 2014). Most species are tropical, with relatively few species occurring in the temperate zone (Bradley 2013). Just over a dozen species in seven genera are found in North America north of Mexico (Opell 2005; Platnick 2014): Uloborus and Hyptiotes are represented by several species throughout the United States and Canada; Miagrammopes (M. mexicanus) is found only in southern Texas; Siratoba (S. referens) and Philoponella species are restricted to the southwestern United States and Texas; and Zosis (Z. geniculata) is found only in the Gulf Coast states. Octonoba sinensis is an introduced Asian species with a wide but patchy distribution east of the Rocky Mountains, where it appears to be confined to greenhouses and barns (Muma and Gertsch 1964; Opell 1979,1983 cited in Opell 2005). Uloborids resemble small araneids, but have a cribellum and calamistrum.
Uloborids are unusual in that they lack venom glands and do not use venom to subdue their prey. Instead, they apply thousands of wrapping movements with their hind legs and use up to hundreds of meters of silk to construct a thick shroud that applies substantial compressive force to their prey. These shrouds sometimes not only restrain prey, but also break the prey’s legs, buckle its compound eyes inward, or kill it outright. The spider then covers the entire surface of its prey with digestive fluid, liquefying it; the spider’s mouthparts usually never touch the prey itself. The silk is eventually consumed along with the prey. (Eberhard et al. 2006; Weng et al. 2006; Bradley 2013)
North Amerixan uloborids make three types of webs: orb webs (Octonoba, Philoponella, Siratoba, Uloboris, and Zosis), triangle webs (Hyptiotes), and simple webs formed of just a few capture lines and lacking a stereotypic architecture (Miagrammopes) (Opell 2005 and references therein). Triangle webs are oriented vertically. In contrast to the orbwebs made by most spiders that spin them (except for most tetragnathids), uloborid orbwebs are typically oriented horizontally. In addition to differences in their webs, North American uloborids vary in where they place their egg sacs. Hyptiotes females deposit their eggs on small twigs, Octonoba females place their egg sacs at the edge of the web, and Zosis females incorporate their egg sacs in the orb (Opell 1984 cited in Opell 2005). Uloborus females attach a growing chain of egg sacs along a radius at the edge of the orb. Philoponella and Miagrammopes females hold their egg sacs with one first leg until spiderlings emerge. (Opell 2005 and references therein).
Philoponella form communal aggregations, with many individuals sharing the support frame strands around their individual orb webs. Individuals in these aggregations often defend their own orbs from other spiders in the group, but in some species they engage in cooperative prey capture (Masumoto 1998 and references therein). Many uloborids add decorations, such as stabilimenta, to their webs (in some cases, young and adult spiders may add different decorations).
Opell (2005) reviewed the taxonomic history of the family Uloboridae.
Uloboridae Thorell, 1869
Uloboridae Thorell, 1869
Spiders in this family are found all over the world. Most species live in warm tropical climates, but we have a few species here in Michigan.
Biogeographic Regions: nearctic (Native ); palearctic (Native ); oriental (Native ); ethiopian (Native ); neotropical (Native ); australian (Native )
Like all spiders, hackled orbweavers have two body-segments, a cephalothorax in front and an abdomen behind. Adults are usually 3-10 mm long. They have eight legs, all attached to the cephalothorax. On the front they have two small "mini-legs" called palps. These are used to grab prey, and in mating, and are much bigger in male spiders than in females. Females in this family are often twice as large as males.
Michigan species in this family have two rows of four eyes each, though some tropical groups only have one row.
Unlike most spiders, this family doesn't have venom glands, their bite is harmless to people.
This is one of a few spider families that make a special kind of woolly, fuzzy silk. They have special structures on their abdomen and hind legs to produce this silk and make it into webs. This is where they get their name, webs made this way are called "hackled." See the Behavior section below for more information on this special webbing.
Most Hackled Orbweavers have dull colors: cream, gray, or brown are the most common.
Other Physical Features: bilateral symmetry
Sexual Dimorphism: female larger
These spiders live in places with some vegetation, so they have places to put their webs. They also prefer warm and humid habitats, but a few species live in dry or cool places too.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: taiga ; chaparral ; forest ; rainforest ; scrub forest ; mountains
Wetlands: marsh ; swamp ; bog
These spiders eat small Insecta and other invertebrates. They spin flat webs that often look like an orb web or a piece of an orb web. Hackled orbweavers usually spin their webs horizontally, unlike the regular orbweaver family that makes their webs vertical.
The webs made by this family aren't sticky. Instead they are made with "hackled" silk, which is fuzzy and has lots of tiny fibers. These little fibers easily tangle up prey. Also, many species of hackled orbweavers stretch their webs and hold them tight. When a prey animal bumps into the web, it lets go of the web so that it collapses around the unlucky insect. Whenever they catch an animal in their web, they grab it and wrap it in more hackled silk. They don't have venom in their fangs, so they rely on their silk to hold their prey still.
Spiders in this family rely on their small size and camouflage colors. They often hide during the day.
- other Araneae
- small Aves
- small Amphibia
Life History and Behavior
Communication and Perception
Like most spiders, Hackled Orbweavers use web-vibrations, touching, and scents to communicate.
Spiders hatch from eggs, and the hatchlings look more or less like grown-up spiders, though sometimes their colors change as they age. To grow they have to shed their exoskeleton, which they do many times during their lives.
Most spiders in this family probably live only a year or two at most.
We know very little about reproduction in this family.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; fertilization (Internal ); oviparous
Females make egg sacks of silks, sometimes attaching them to twigs or branches, sometimes lining them up in their webs. Unlike other spider groups, the silk of the egg sacks is often gray or brown.
Parental Investment: female parental care
Molecular Biology and Genetics
Statistics of barcoding coverage
Specimens with Sequences:163
Specimens with Barcodes:144
Species With Barcodes:33
No Hackled Orbweaver species are known to be in danger, but there are many species still unknown to science.
Relevance to Humans and Ecosystems
Economic Importance for Humans: Positive
These little spiders probably help eat insect pests, but the don't have any strong impacts on humans. A few species are found around houses, and some people may consider this a nuisance.
Uloboridae, the cribellate orb weavers or hackled orb weavers, is a family of non-venomous spiders. Their lack of venom glands is a secondarily evolved trait. Instead, they wrap their prey thoroughly in silk, cover it in regurgitated digestive enzymes and then ingest the liquified body. 
All members of this family produce a feathery, fuzzy silk called cribellate (or hackled) silk. These spiders do not use an adhesive on their orb webs, but rather the very fine fibers on each strand of silk tend to ensnare prey. Uloboridae webs often have a stabilimentum or zig-zag pattern through the center.
This family has an almost worldwide distribution. There are only two species known from northern Europe: Uloborus walckenaerius and Hyptiotes paradoxus. Similarly occurring solely in northern North America (e.g. southern Ontario) is Uloborus glomosus.
- Ariston O. P-Cambridge, 1896 (Central America)
- Astavakra Lehtinen, 1967 (Philippines)
- Conifaber Opell, 1982 (South America)
- Daramulunia Lehtinen, 1967 (Samoa, Fiji, New Hebrides)
- Hyptiotes Walckenaer, 1837 (Palearctic)
- Lubinella Opell, 1984 (New Guinea)
- Miagrammopes O. P.-Cambridge, 1870 (America, Austrasia)
- Octonoba Opell, 1979 (Russia, Central Asia to Japan)
- Orinomana Strand, 1934 (South America)
- Philoponella Mello-Leitão, 1917 (Africa, America, Asia, Australia)
- Polenecia Lehtinen, 1967 (Mediterranean to Azerbaijan)
- Purumitra Lehtinen, 1967 (Australia, Philippines)
- Siratoba Opell, 1979 (USA, Mexico)
- Sybota Simon, 1892 (South America)
- Tangaroa Lehtinen, 1967 (Oceania)
- Uloborus Latreille, 1806 (worldwide)
- Waitkera Opell, 1979 (New Zealand)
- Zosis Walckenaer, 1842 (Pantropical)
- Jonathan A. Coddington & Herbert W. Levi (1991). "Systematics and evolution of spiders (Araneae)" (PDF). Annual Review of Ecology and Systematics 22: 565–592. doi:10.1146/annurev.ecolsys.22.1.565. JSTOR 2097274.
- Brent D. Opell (1984). "Lubinella, a new genus of Uloboridae (Arachnida, Araneae)" (PDF). Journal of Arachnology 11: 441–446. JSTOR 3705054.
- Data related to Uloboridae at Wikispecies
- Media related to Uloboridae at Wikimedia Commons
- World Spider Catalog
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