EPOW - Ecology Picture of the Week

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Invader in Your Garden: European Garden Spider

Credit & Copyright: Dr. Bruce G. Marcot

Explanation:  Beware the invaders!  This creature is not of this world!  Hide your children!  It's a European garden spider! OK, histrionics over, actually it's not particularly harmful ... and it's just from another continent (Europe) ... but it is an "alien species" nonetheless.  Exotic species introduced by humans often wreak havoc on native species and ecosystems.  The European garden spider -- one of the larger orb-weavers -- now ranges clear across North America and has become quite common.  It is unclear what its ecological effects are on native spider species.  However, this species also may be beneficial by helping to reduce populations of undesirable insects.   Long ago, this species -- also called the "cross spider" for the pattern on the back -- was revered in Europe because of the cross.  Some sources say that a clean web of this species can be used on a cut to stop bleeding and heal the wound.   However, in 1710, the physicist René-Antoine Réaumur calculated that it would take 27,648 female garden spiders (and many more flies, as food for them) to produce one pound of silk! As an extraterrestrial experiment, two European garden spiders and two flies accompanied three astronauts on July 28, 1973, when the Apollo spacecraft with Skylab II was launched.  The experiment showed that the spiders could successfully build orb-webs in microgravity conditions.  See, these spiders really are not of this Earth after all! Information:  Hillyard, P. 1994. The book of the spider: a compendium of arachno-facts and eight-legged lore. Avon Books, New York. 218 pp.

Next week's picture:  Happy Holid-ecology!