The types of spiders that people normally come across in daily life are often found in home, garden and lawns across North America.
Formally spiders can be arranged according to families and less formally spiders can be categorized according to their hunting methods. Some spiders use webs to trap prey. Some spiders hunt prey in their territory. Both ways of organizing spider identification help with spider identification, and the species and pictures are presented below using both methods.
Before or after reading, check out the collection of spider videos presented at the top of the page. Most are quick takes, approximately thirty seconds, and they show the spiders in real life situations.
Because of their specialized hunting method, web building spiders typically have a larger number of silk glands than hunting spiders.Spiders are often further classified according to the types of webs they build. Three of the better known groups of spiders that build different types of webs are the orb weavers, cobweb spiders and funnel weavers. Many common garden spiders, such as the writing spider, are orb weavers.
Cobweb spiders belong to the family Theridiidae. They make their multidimensional webs in many homes and gardens. Most references you read on the internet also point out that black widow spiders (redback spiders in Australia) belong to this family.
Funnel web spiders (family Agelenidae) also go by the name grass spiders because their webs are commonly found at ground level. Like cobweb spiders, their webs are multidimensional, with the added feature of a built in funnel shaped hole. It serves as protection as the spider waits to catch prey. There are close to one hundred different species of funnel web spiders in the United States.
Above average spiders in round, flat webs found around the lawn and garden often belong to the Araneus genus of spiders, pictured.
Because of their size, the size of their web and their affinity for living in residential settings, many people refer to araneus spiders as garden spiders, without knowing their taxonomic group.
Argiope spiders often go by the name garden spiders or writing spiders, and they are credited as the inspiration for one of the world's most popular spiders, Charlotte of Charlotte's Web.
While most people associate orbweavers with round bodies, the Arrowshped Micrathena represents on of a handful of orbweavers with spiky or pointed bodies.
The red part of the legs often serves as a useful starting point for identifying Spotted Orbweavers.
The Six-spotted Orbweaver is fairly small and colorful, with the six black abdominal spots providing the best identification clue.
Golden Silk Orbweavers are known as the spiders that build the largest orb or circular web in North America.
Most spiders have eight eyes and you can identify spiders by the eye arrangement.
The 2-4-2 eye arrangement of the spider in the picture indicates it is a wolf spider.
Well over two dozen North American Phidippus jumping spiders inhabit the brush and walls around residential areas.
Differences among Phidippus deal more with color than with body form. Generally, Phidippus species have darker banded legs, with shades of black, brown, red or yellow on the cephalothorax and abdomen.
The majority of Lynx Spiders (family Oxyopidae) live in tropical and subtropical areas of the world.
However, species in three different genera can be found in the United States.
The are small to medium sized hunting spiders, and like the crab spiders and jumping spiders, their preferred habitat consists of low growing plants and bushes.
Tarantulas are timid spiders that inhabit southern areas, especially the Southwest.
Yellow Sac Spiders (Cheiracanthium) commonly inhabit residential areas and can wind up on walls. While they are not considered spiders of medical importance (more commonly known as poisonous), their bite can be painful.
Spiders, long considered carnivores, (although there might be exceptions to that rule), traditionally choose insects and other arachnids as their primary source of food.
Arachnologists, scientists who study spiders, have long been intrigued by spider diets. One question they consider, "Are Spiders Picky Eaters", has been the subject of both observation and scientific experimentation.
Like all scientists, when arachnologists conduct experiments on spider diets, they are trying to stay as objective as possible with respect to the potential answers.
Objectivity in scientific experimentation often loosely translates into scientists trying to prove their thinking is wrong, rather than prove their thinking is correct. Scientifically, the process is known as testing the null hypothesis.
They conducted an experiment with an Araneidae species, an orb weaving spider (Micrathena Gracilis).
Over an extended period of time, they counted the number and size of insects that flew into the web. They also recorded the number and size of the insects that the spider captured for dinner.
Testing the null hypothesis meant that the researchers thought that the spider would eat all the insects that landed in the web, regardless of insect size.
At the end of their experiment, they concluded that when given the choice between large and small insects caught in the web, the spider preferred larger insects.
In scientific terms, they concluded there was a statistically significant relationship between spider diet and insect size. The hypothesis that spiders are picky eaters still stands.
© 2001-2016 Patricia A. Michaels