INTRODUCTION
The common name cellar comes from these spiders being frequently found in dark
and damp places such as cellars, basements, and crawl spaces, and that of daddylonglegs
from their very long, thin legs which give them an appearance somewhat similar to
harvestmen/daddylonglegs (order Opiliones, family Phalangiidae; see similar groups below).
Cellar spiders are nuisance pests, probably more because of their webs than the spider
itself. About 20 species are found in the United States and Canada.
RECOGNITION
Adult body length ranges from about 1/16-5/16" (2-8 mm); cephalothorax and
abdomen connected by tiny waist (pedicel) but appearing as small body with very long,
thin legs. Color usually pale yellowish to light brown or gray. Usually with 8
eyes, some species with 6, usually with 2 widely spaced groups of 3 closely-spaced
eyes each and 2 eyes in between. Chelicerae (fangs) fused at base, cheliceral claw
short and opposed (closes to/opposite) by a short toothlike projection of basal segment.
Abdomen either globose or elongate. Tarsi with 3 claws each.
SIMILAR GROUPS
Harvestmen/Daddylonglegs (order Opiliones, family Phalangiidae) with
cephalothorax and abdomen broadly connected giving appearance of singular oval body, I
pair ocalli, and tarsi with I claw each.
REPRESENTATIVE SPECIES
- Long-bodied cellar spider, Pholcus phalangioides (Fuesslin). Adult female body
length about 1/4-5/16" (7-8 mm) with front legs about 1 3/4-1 15/16" (45-50 mm)
long, male body length about 1/4" (6 mm); with 8 eyes in 2 lateral groups of 3 each
and 2 smaller eyes in between; abdomen elongate, cylindrical, about 3 times longer than
wide; found worldwide.
- Short-bodied cellar spider, Sphermophora meridionalis Hentz. Adult female body
length about 1/1 6" (2 mm) with front legs about 5/16" (8.5 mm) long, male body
length about 1/16" (1.6 mm) with front legs about 3/8" (9.5 mm) long;
cephalothorax pale yellow with 2 light gray spots, abdomen pale yellow; with 6 eyes in 2
lateral groups of 3 each; abdomen globose; found in eastern United States.
BIOLOGY
The long-bodied female cellar spider may produce up to 3 egg sacs containing
13-60 eggs each. The sacs are very thin such that the cluster of eggs shows through,
giving the appearance of an unripened blackberry. The female typically carries the egg sac
between her chelicerae Oaws) until they hatch. The emerging spiderlings often cling to
their mother for a short time. There are 5 molts before maturity is reached, and this
usually requires about I year. Adults typically live about 2 years. The short-bodied
female cellar spider produces a similar egg sac containing 10-27 eggs each, and also
carries it in her chelicerae.
HABITS
Cellar spiders construct loose, irregular webs in corners. They hang upside down
on the underside of the web. The webs are not cleaned but instead new web is continually
added. This habit can result in extensive webbing in a relatively short time.
Webs are commonly found in dark and damp places such as cellars,
basements, and crawl spaces. They can also be found in the corners of garages, sheds,
barns, and warehouses, on eaves, windows, and ceilings, and in closets, sink cabinets, and
bathtraps. In commercial buildings and warehouses, these spiders tend to be in corners
near doors which are left open. Open doors allow many flying insects to enter which means
more food.
Cellar spiders seem to fare better in areas
with higher relative humidity (RH). The higher RH may be due to older construction,
improperly vented crawl spaces, excessive ground moisture, improperly sealed basement
walls, leaking/sweating plumbing pipes, leaky flashing, roof problems, etc. This increased
RH attracts and helps support insect prey. When disturbed on its web, the long-legged
cellar spider has the habit of rapidly shaking its body in a rotary movement. This causes
the web to vibrate enough to blur both spider and web, making the spider seem to
disappear. If the disturbance is caused by insect prey, this vibration helps to further
entangle the prey. If disturbed too much, the spider will retreat to a corner or drop from
the web to escape.
