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Some Spiders Still Active

10-29-18 march fly and spider_U1A1162Spiders are ectotherms – warmed and cooled by their environment. In the fall, those outdoor species that remain alive through the winter begin preparing themselves by producing antifreeze proteins that allow their tissues to experience below-freezing temperatures. When a small particle of ice first starts to form, the antifreeze proteins bind to it and prevent the water around it from freezing, thus preventing the growth of an ice crystal. Some species survive in temperatures as low as -5 degrees Celsius.

The pictured hammock spider, still active in late October, is nourishing itself by drinking the dissolved innards of a fall-flying March fly, whose name comes from the predominantly springtime flight period of most March Flies (of the 32 species in the genus Bibio in North America, only three fly in fall).

A common belief is that once cold weather appears, outdoor spiders seek shelter inside houses.  In fact, only about 5% of the spiders you find in your house lived outside before coming into your house, according to Seattle’s Burk Museum.  The reason people tend to notice them more inside may be because sexually mature male spiders become more active in the fall, wandering far and wide in search of mates.

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5 responses

  1. susan thomas

    so do some spiders stay active all winter outside here in new england?

    October 29, 2018 at 8:48 am

  2. Alice Pratt

    Spiders are interesting to watch.

    October 29, 2018 at 9:06 am

  3. I was thinking that many spiders hibernate in the winter, so that they don’t need/take in food?? Thanks for the post.

    October 29, 2018 at 10:33 am

  4. Interesting info to learn as always, thanks, Mary!

    October 29, 2018 at 11:16 am

  5. Ruth Gross

    Julie the Annunity – I am busy from the time I get up at about 6-7, off to the gym then home Eat breakfast, Bible study, class Tues. evenings weekly – no need to list all to be done each day.

    I am making popcorn balls for kids Wednesday – so that will take time.

    I Must get my haircut!! It has never looked this discheveled !

    Perhaps we can meet at Annapolis in the AM Nov. 5 – depends On what day I can get my hair cut. I will let you know then we can lake appt. . AR

    Sent from my iPad


    October 29, 2018 at 6:08 pm

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