Spider Homepage

Agelenidae—Funnel Weavers
      Grass Spiders (Agelenopsis species)
      Barn Funnel Weaver (Tegenaria domestica)

Amaurobiidae—Hackledmesh Weavers
      Hackledmesh Weavers (Amaurobius and
      Callobius species)

Araneidae—Orbweavers
      Yellow Garden Spider (Argiope aurantia)
      Banded Garden Spider (Argiope trifasciata)
      Marbled Orbweaver (Araneus marmoreus)
      Cross Orbweaver (Araneus diadematus)

Clubionidae—Sac Spiders
      Broad-Faced Sac Spider (Trachelas tranquillus)

Dysderidae—Dysderid Spiders
      Woodlouse Hunter (Dysdera crocata)

Lycosidae—Wolf Spiders
      Wolf Spiders (Hogna [previously known
      as Lycosa] species)

Miturgidae—Prowling Spiders
      Agrarian Sac Spider (Cheiracanthium  inclusum)
     and Longlegged Sac Spider (Cheiracanthium mildei)

Pisauridae—Nursery Web Spiders
      Fishing Spider (Dolomedes tenebrosus)

Pholcidae—Cellar or Daddylonglegs Spiders
      Longbodied Cellar Spider (Pholcus phalangioides)

Salticidae—Jumping Spiders
      Bold Jumper (Phidippus audax)

Sicariidae—Sixeyed Sicariid Spiders
      Brown Recluse Spiders (Loxosceles reclusa
      and other Loxosceles species)

Theridiidae—Cobweb Weavers
      Common House Spider (Achaearanea tepidariorum)
      Southern Black Widow Spider (Latrodectus mactans)
      False Black Widow (Steatoda grossa)

Spider Management

Glossary

References

Photographs courtesy of Steven Jacobs.
Male brown recluse spider photograph
courtesy of Rick Vetters.

Prepared by Steven Jacobs,
senior extension associate in
urban/public health entomology.

Introduction

Spiders, along with daddylonglegs, ticks, mites, and scorpions, belong to the class Arachnida. They are beneficial animals that feed on all sorts of arthropods, including insects. About 3,000 species of spiders are found in the United States. Spiders rarely bite people, and most species found in the world are harmless. However, some people may be allergic to a spider’s bite, and a few species of spiders are known to produce bites that may have serious medical implications for humans. Two of the more medically important types are the black widow spiders, and the brown recluse spider and its relatives. These two types of spiders are rarely encountered in Pennsylvania. Although black widows can be found native in Pennsylvania, the brown recluse spiders must be introduced and cannot survive in Pennsylvania’s climate unless they remain inside heated structures. Many spiders indigenous to Pennsylvania will come into homes, mostly during the autumn, and a few of the more common and important of these will be discussed here.

To facilitate an accurate description of each of these species, and to aid the reader, a glossary of terms is included at the end of this publication. Sizes indicated in the “Description” subsections under each species refer to the length of the spider from the front of the cephalothorax to the rear of the abdomen.

A Note on Venom: “Toxic Venoms” and “Poisonous Venoms”
For the most part, all spiders have jaws and fangs to deliver venom. However, most spider bites have little or no effect on humans. The exceptions include people with compromised immune systems or other medical conditions that leave them vulnerable to spider venoms. Most spiders are too small to be of concern to humans. The fangs of these tiny creatures cannot penetrate the human epidermis unless the spider is held in place and allowed to bite the very thin skin between the fingers or toes. Larger spiders can bite, but they are shy and will attempt to escape unless trapped between the skin and some other object (e.g., clothing, sheets, and shoes).

Venoms from any spider are poisonous and/or toxic to their prey, but most are not poisonous or toxic to humans. The terms “poisonous venoms” and “toxic venoms” are somewhat misleading and should be replaced with “potentially harmful venoms.” Very few spiders produce venoms that are potentially harmful to humans.

*** Disclaimer ***

Authored by: Steve Jacobs, Sr. Extension Associate

March 2002
Revised 2006

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