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Friday, August 4, 2017


Friday, 9:00 AM.  56 degrees at the ferry dock and on the back porch as well.  Wind variable, with light to moderate gusts.  The sky is cloudy and overcast, after rain showers yesterday and last night. The humidity is 89%.  The barometer reads 29.66" and is still falling, predicting more unsettled weather, with temperatures in the low seventies.
   Purple loosestrife, Lythrum salicaria, in the Loosestrife Family, the Lythraceae, is blooming now in wet roadside ditches and marshes.  It s a strong growing perennial native to Europe, Asia and northern Africa that has been popular as a garden ornamental plant in Europe and America for many years. The species name refers to the plant's leaves, which resemble those of the willow (salix). The plant also has medicinal qualities as an astringent.   It is quite attractive,  but unfortunately spreads readily by seeds and plant parts and is very invasive, particularly in wetlands, where it competes with cattails and other native wetland plants that are valuable to wildlife. It also grows so profusely that it can clog waterways and impede the flow of water.   For these reasons it was declared a noxious invasive plant many years ago in Wisconsin and most other states.
   Purple loosestrife can be controlled by mechanical means (digging and disposing of he plants) and by chemicals (primarily Roundup), but those controls are expensive and problematic.  The Galerucella beetle, which feeds exclusively on purple loosestrife, was introduced in 1994 from Europe to control it.  Several other weevils also feed exclusively on this invasive plant, and are also used in its biological control.  
   The Galerucella beetle has been distributed free of charge to citizen volunteers, who raise and distribute the beetles and monitor loosestrife populations, under the supervision of the Wisconsin Department of Natural Resources.  This program has been amazingly successful, and today purple loosestrife is basically under control in the state.  Wetlands and other areas that once were overrun by purple loosestrife are now mostly free of it, and the occasional loosestife bloom is nothing more than an accent among the native plants.
     A truly good aspect of the biological control of organisms is that it does not aim to completely eradicate a target population, a residual of which must remain in the environment as host for survival of the control species.
  I often rail against government programs and agencies that are overblown and out of control, but purple loosestrife eradication is an environmental success story, a cooperative program among scientists,  government agencies, and citizen volunteers that has efficiently and economically solved a real-world ecological problem.

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