|Black and Yellow Argiope, aka Garden Spider|
Spiders eat many types of nuisance and plant damaging insects, including mosquitoes, stink bugs, caterpillars, aphids, and beetles. Actually they will eat just about any insect they can get their fangs on, including other beneficials, though on the whole they eat a lot more bad bugs than good ones. In turn, spiders are an important food source for many species of birds, serving as both predator and prey in the food web.
Spiders are common in gardens and landscapes in our area throughout the year, though their numbers are generally highest in late summer and fall. An over abundance of spiders in your yard or home is an indication that there are plenty of insects around for them to eat. If you have a lot of spiders around and you can tolerate them, the best thing you can do is leave them alone to allow them to naturally reduce the insect population.
Learn more about spiders by reading the rest of the article on the Pender Cooperative Extension website: http://pender.ces.ncsu.edu/index.php?page=news&ci=LAWN+141. See images of many common garden spiders on this NC Extension webpage: http://www.ces.ncsu.edu/depts/ent/notes/Other/note137/note137.html.