Hackled orbweavers (Uloboridae)
Feather-legged lace weaver (Uloborus plumipes)
Web: horizontal (!) orbweb of 15 to 30 cm.
Habitat: The Feather-legged lace weaver is originally a tropical species that was imported in Belgium through the Mediterranean. It is almost exclusively found in heated spaces such as greenhouses. In garden centres you can spot the typical webs, hung between cacti and succulents. This species has only once been found outdoors in Belgium.
How to recognize:
Looks similar to:
The very noticeable abdomen, together with the specific occurrence in heated spaces means that this species is easily recognized.
Size
♀: 4-5 mm
♂: 3-4 mm
When?
Can be found throughout the year.
Cellar spiders (Pholcidae)
Marbled cellar spider (Holocnemus pluchei)
Web: an open, messy, 3D web, often with a dome like structure.
Habitat: almost always in (non)heated industrial buildings such as warehouses, hangars or garden centres. Often in corners.
How to recognize:
Looks similar to:
Size
♀: 5-7,5 mm
♂: 5-7 mm
When?
♀: throughout the year
♂: throughout the year
Cobweb spiders (Theridiidae)
Southern black widow (Latrodectus mactans)
Web: fairly large, 3D web with messy threads and often vertical threads with glue on the lower part towards the substrate (“gum footed threads”).
Habitat: The Southern black widow has not yet established permanent populations in Belgium. Observations are always the result of unintended hitchhiking from the original range (southern part of USA and Mexico). A lot of Southern black widow spiders are introduced by shipments of second-hand cars from USA in the Antwerp harbour.
How to recognize:
Looks similar to:
Size
♀: 15 mm
♂: 6 mm
Zoropsid spiders (Zoropsidae)
Spiny false wolf spider (Zoropsis spinimana)
Web: The Spiny false wolf spiders doesn’t make a web, but is an active and visual hunter.
Habitat: Mainly in and around houses. In Southern-Europe underneath stones, bark. Hunts at night.
How to recognize:
Looks similar to:
Size
♀: 10-19 mm
♂: 10-13 mm
When?
♀: throughout the year
♂: throughout the year
Eutichurid spiders (Cheiracanthiidae)
Yellow sac spider/Spiny false wolf spider (Cheiracanthium mildei)
Web: The Yellow sac spider doesn’t construct a web, but catches its prey through active, visual hunting.
Habitat: The Yellow sac spider can be found in a sac-like retreat in a curled up leaf or underneath stones and bark. In Belgium especially close to or in buildings (but recently also in a nature reserve, far removed from buildings.
How to recognize:
Looks similar to:
Cheiracanthium virescens: this species lives mainly in heathland and will almost never occur near or in houses. Certain identification only through using a stereomicroscope.
Size:
♀: 6-11 mm
♂: 6-9 mm
When?
♀: May till December
♂: May till December