Spider Question

Asked August 25, 2019, 12:12 PM EDT

Can you identify what kind of spider this is? It's always bunched up like that, so this is the best I could get. It lives inside the right side mirror of my mother's car. It also has an identical neighbor living on the left side. Neither of us want to disturb them since they don't try to hurt us, but we are curious about the species and whether we should actually be concerned or not. Thank you!

St. Clair County Michigan

1 Response

That is a Cross Spider, Araneus diadematus (Araneidae).

The Cross Spider is among the largest orb spiders found in Michigan. It was apparently introduced from Europe where it is known as the Garden Spider. The body is brownish orange in color with distinctive white markings on the back of the abdomen. The legs are relatively long and appear to be banded. The abdomen above bears a median row of diamond-shaped silvery spots. There is usually a pair of white spots at right angles to this median row, giving this group the form of a cross (hence the common name). The Cross Spider occurs throughout the eastern US and other northern states west to Washington and Oregon. It is found throughout Europe and much of Asia including Japan. It is a very common spider in Michigan. It feeds on flying and jumping insects including grasshoppers, flies, other spiders, and most bugs that become trapped in its large, orb-shaped web. Webs can be found among shrubs and in wooded areas. It is also found on herbaceous growth in marshy places and grass in meadows and pastures. Females attach egg mass to a leaf, twig, or other support at the side of their webs. Spiderlings usually stay in the egg sac until their first molt. These spiders are not particularly dangerous but they will bite if threatened or handled roughly. The occasionally find their way indoors during the fall of the year.