Wednesday, June 26, 2013

Wildflower Wednesday #11

There are lots of flowers in bloom at the Nature Center this week, but the most noteworthy find was the first milkweed flowers of the year!  While most of the milkweed flowers have yet to open (any day now), visitation was high at the flower I found near the parking lot.


While foraging for sweet nectar, this fly picked up an unintended passenger: pollen.  When insects sit on milkweed flowers, their feet can fall through "trap doors" and come in contact with a sticky ball of pollen called a pollinia.  The unwitting carrier of pollen then brings the pollinia to another milkweed flower, and if that foot again slips in a "trap door," pollination may be successful!  Our good friend, Kent McFarland, at Vermont Center for Ecostudies, describes the process well in his blog post here.


Look closely at the fly and you can see a pollinia attached to a hind leg, causing the leg to drag back.  The extra weight of a pollinia can have adverse effects on the insect carrier.  After leaving the milkweed plant, watch this fly try to remove pollinias, which now cover half of its legs (best viewed in fullscreen mode)

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