Purple Loosestrife -- The Beautiful Invader
© 2008 Dave Spier
Purple Loosestrife is a tall, wetland plant sporting beautiful magenta flowers with six (sometimes four or five) petals surrounding a small yellow center. Clusters of these blossoms grow in dense whorls around a fuzzy, square stem. Pointed leaves grow in opposite pairs (sometimes whorls of three) below these flower spikes. The species is native to Europe. As early as Roman times, it was tied to the yokes of oxen in the belief that it appeased or ended strife and unruliness between the animals as they plowed. It was said to "loosen strife," hence the name loosestrife.
How could such a beautiful plant be a problem? We'll get to that in a moment.
Purple Loosestrife (Lythrum salicaria) was brought to eastern North America in the early 1800's to be used in flower gardens. If it had stayed where it was planted, we'd have little trouble. Since then it has spread westward across much of Canada and the United States. Loosestrife is a hardy perennial that takes over wetlands, crowding out the native cattails that our wildlife depends on. To give you an example, Black Terns (a declining species) depends on old, broken cattails for nesting material. The stiff, almost woody stems of loosestrife are not readily broken. Loosestrife is almost worthless from wildlife's point of view. For the most part, nothing eats it, although I once saw sparrows feeding on the seeds in late summer.
Loosestrife can also encroach on drier crop fields and pastures where it becomes a more direct economic issue. Each mature plant can produce up to 2.7 million seeds in one growing season. The rootstock also sends out 30 to 50 shoots that create a dense, monocultural web underground. This effectively chokes out "competing" vegetation.
On this side of the Atlantic, there are no natural controls for Purple Loosestrife. Our wildlife does not eat it or use it for breeding habitat. In Europe, over 100 insects feed on various parts of the plant. From these, five beetle species were selected and introduced into this country under controlled (caged) conditions. Some of the testing was done at Montezuma National Wildlife Refuge near the visitor's center east of Seneca Falls, NY. After determining that these beetles posed no threat to our desirable vegetation, they were released into the wild. Two of the insects feed on the leaves and new shoots; these are the kind released at Montezuma. A third beetle, a type of weevil, bores through the roots. The last two species eat the flowers. Some of the beetles were also released at Blue Cut Nature Center between Newark and Lyons in Wayne County, NY.
While these natural insect controls spread and multiply, a number of other steps need to be taken. So-called "sterile" varieties of garden loosestrife have been shown to cross-pollinate with wild Purple Loosestrife and produce viable seeds. Gardeners are asked to avoid planting loosestrife or any of its 26 cultivars. If it already grows in your garden, cut off the flower spikes as soon as the petals begin to drop and dispose of them in a plastic bag. Incineration is effective, but generally prohibited. If you are planting wildflowers, check the seed mix packets and make sure there is no loosestrife. Small infestations of loosestrife can be controlled by digging and hand pulling. Larger patches can be controlled by constant cutting. Chemical control usually requires a permit because of the danger to wetlands. Check with the Department of Environmental Conservation if you live in New York State or the state agency where you live.
In areas where loosestrife has already taken over a marsh, the best we can probably do for now is admire the beautiful color and wait for the beetles to arrive.
Contact Dave at firstname.lastname@example.org
(This copyrighted article and photo first appeared in The Times of Wayne County, July 28, 2008. All rights reserved.)
Tuesday, July 29, 2008
Wednesday, July 23, 2008
This blog has been revised and reposted with additional photos on September 6, 2012.
Thursday, July 10, 2008
Little Red Bugs - © Dave Spier
Do you have little red bugs in your yard? Multiple clusters of 10 to 20 or so, hundreds all together, are crawling around the maple leaves that blew up against our garden fence last fall. I left the dead leaves there as mulch to control the weeds. Among the leaves are skeletonized maple seeds and the tiny bugs seem to be sucking some sort of nourishment from the seemingly dead and dried samaras (the botanical name for these winged seeds).
Closer examination of these insects with red abdomens (actually red with some bright-orange markings) reveals darker wing pads beginning to grow backwards from the shoulders. Small heads look back at me through dull red eyes. Long antennae could be mistaken for a fourth pair of legs. These are the nymphs of the Eastern Boxelder Bug, Boisea trivittata, (syn. Leptocoris trivittatus), a member of the Order Hemiptera, or True Bugs. After several more molts, each successively larger, the immature nymphs will transform into flying adults about a half-inch long. Most of the red color is lost, save for a few red edges on the forewings and three red lines on the thorax just behind the head. They are named for their favorite food, the seeds of Boxelder trees, also known as ash-leaved maples, a reference to the compound, opposite leaves reminiscent of the unrelated ash tree. Perhaps they can't tell the difference because Boxelder Bugs sometimes also feed on ash and, occasionally, a variety of other plants and fruits.
In the fall, adult Boxelder Bugs become a nuisance by inviting themselves into the warm, cozy interiors of our homes. The first sign of trouble may be swarms of the bugs on sunny exterior walls. From there they find tiny cracks through siding or past windows and under doors. The good news is they do not sting, transmit disease, damage structures, destroy fabrics, infest food or carry filth. When spring arrives, they leave in order to lay their eggs on Boxelder trees or other suitable venues which seem to have included the maple-leaf litter along my fence, although I do have a Boxelder tree on the northeast corner of the property some distance from the fence, and fortunately far from the house. Incubation of the eggs takes about two weeks and then "voila!" Swarms of little red bugs begin milling about.
In early July, we were also dealing with Squash Bugs, Squash Vine Borers, Three-lined Potato Beetles, White Cabbage Butterflies and Japanese Beetles as well as deer (I'm guessing) eating broccoli leaves. So far, the garden fence is rabbit and woodchuck proof and I think we found a good deer repellent now.
- - -photo notes: exposure was 1/200 sec. at f/13 using the Canon MP-E 65mm (1-5x, but actual magnification not recorded) with twin macro flash on a digital Rebel (6 mp)
This was written from a New York perspective (specifically the northern Finger Lakes region). Corrections, comments and questions are always welcome at email@example.com or connect through my Facebook page and photo page. There's also a community-type page for The Northeast Naturalist. Other nature and geology topics can be found on the parallel blogs Adirondack Naturalist and Heading Out.
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(The original copyrighted article and photo [taken June 29] first appeared in the Times of Wayne County, July 7, 2008. All rights reserved.)