The Daddylonglegs Spider

Common Name:
Cellar or Daddylonglegs Spiders
Scientific Name:
Various
Class/Order/Family:
Arachnida/Araneae/Phoicidae
Metamorphosis:
Simple

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

  1. 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.

  2. 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.