The Fowl Meadow Area of Critical Environmental Concern, awash in the magenta-colored flowers of exotic, invasive Purple loosestrife, several years ago.

Wetland Restoration 

Fowl Meadow Purple loosestrife 

biological control project

Purple Loosestrife and Galerucella Growth Timeline

January through March

Galerucella adults that were born the previous summer lie dormant in the leaf litter at the base of Purple loosestrife plants, or within Purple loosestrife stems, depending on the water levels at the site. No green growth is visible, yet.

April

Throughout April, there is still no sign of Galerucella insects. And, in early April, the Purple loosestrife rootballs still show no signs of greenery. 

However, by mid- to late April, the rootballs start to sprout red-green buds and shoots. 

May

In early to mid-May, the potted Purple loosestrife plants have relatively short but quickly growing shoots. (Note that some Beetle-Ranchers will have short plants right about now, while others' plants will be far taller - potentially a result of the rootballs, the soil mixture, and/or the growing conditions.) Beetle-Ranchers may begin to find a few Galerucella beetles roaming the leaves of their plants.

In late May, at the wetland treatment sites, wild-growing Purple loosestrife is still short, and there is evidence of feeding by last season's Galerucella beetles that recently climbed out of the leaf-litter. The beetles are flying around, feeding on Purple loosestrife, mating, and laying eggs. The beetles' chew-marks are visible on the plants, as are their eggs, though far more difficult to notice (they're tiny - about the size of a pin-head).

June

In early June, the chew holes left by adult Galerucella beetles continue to be visible, in addition to the leaf-stripping done by the larvae. 

In mid-June, the potted and wild Purple loosestrife plants are generally about 6" to 18" tall, at most (and some are far shorter, green and holey).  Galerucella larvae and beetles continue to feed.

In late June, a few Purple loosestrife plants are beginning to sport flowers.

July

In early July, out in the wetland treatment sites, there are scattered Purple loosestrife flowers, and the plants, themselves, are in a variety of states. Some plants are short, green and non-flowering. Others are brown, shriveled, and dry. In still other areas, Purple loosestrife is being actively fed upon by Galerucella. Also at this time, pale-colored adult Galerucella beetles (possibly new-generation beetles) are visible, and larval leaf-stripping continues.

Even in late July, some Purple loosestrife plants are barely chewed by the Galerucella! Also at this point, the Purple loosestrife plants that can flower are in full bloom.

August

In early August, out in the wetland treatment sites, Purple loosestrife that has not been significantly attacked by Galerucella continue to be in full bloom. Few if any Galerucella are visible throughout August.

September

Only a very few Purple loosestrife flower spires are visible at the wetland treatment sites in September. Galerucella are not evident.

October

In early October, Purple loosestrife plants (that have not been devoured by Galerucella) are still green. 

By mid-October, the plants are beginning to turn fall colors. 

By late October, there are many desiccated looking Purple loosestrife plants. No flowers are evident, nor Galerucella.

November

In November, Purple loosestrife continues to show fall colors, and Galerucella are not evident.

By late November, Purple loosestrife plants are dried looking. 

December

No Galerucella activity is visible.

 

 

Feb. 2010