Vining menaces

In the NYT on the 21st, a story with the headline (in the print edition) “Weevils From Asia To Combat Park Vines” by Keith Mulvihill. I was attracted by the phrase weevils from Asia in the head, because of its poetic properties (it would make a nice starting point for a poem, though weevils from Africa would have had better prosody), and by the topic of invasive vines. (On-line, the head was the less poetic: “Urgent Task for Insect: Stop a Relentless Vine”.) And then there’s the great common name (only too descriptive) mile-a-minute vine. The beginning of the story:

In many people’s minds, the weevil is associated with ravaged crops, ruined farmers and vast, forsaken fields, but New York City is about to unleash some 5,000 Asian weevils in several parks to attack a prolific vine that poses a threat to native plants and trees.

The beetles, each roughly the size of a sesame seed, are part of a broad strategy to combat the relentless mile-a-minute vine, which has invaded parks and forests from North Carolina to Massachusetts and as far west as Ohio.

Known scientifically as Rhinoncomimus latipes, the insects are considered biological control agents by invasive plant experts and are to be released at two places each in the Bronx and Queens and one on Staten Island.

Mile-a-minute covering stuff (including a close-up):


Mile-a-minute in Wikipedia:

Persicaria perfoliata (syn. Polygonum perfoliatum) is a species of flowering plant in the buckwheat family, Polygonaceae. Common names include mile-a-minute weed, devil’s tail, and giant climbing tearthumb. It is a trailing herbaceous annual vine with barbed stems and triangular leaves. It is native to most of temperate and tropical eastern Asia.

The old genus Polygonumpolygon figures obviously in the name — includes some pleasant ornamental vines, some minor weeds, and some rampant invasives.

More from the NYT on mile-a-minute:

The vines were first spotted in Pelham Bay Park in the Bronx in 2006. “When we saw that mile-a-minute was growing there, we panicked,” said Katerli Bounds, the director of forest restoration for the city’s Department of Parks and Recreation. The park, she said, contains one of the best examples of natural forest in the city.

… Mile-a-minute vine is native to Asia, but it is believed that at some point in the 1930s, its seeds contaminated a shipment of holly seeds in Japan, said Judy Hough-Goldstein, a professor of entomology and wildlife ecology at the University of Delaware at Newark. Dr. Hough-Goldstein, who studies the relationship between insects and mile-a-minute, said those holly seeds were shipped to a nursery in York, Pa.

The vine has triangular leaves and can grow up to 20 feet in a single growing season, creeping up and over nearby plants and trees. Under ideal conditions, a single plant can produce thousands of seeds, which can germinate in the soil for up to six years after falling to the ground.

“The spread of mile-a-minute is strongly tied to soil disturbances,” Dr. Hough-Goldstein said. Walking paths, roadsides, fallen trees — almost any exposed bit of ground will do.

Then on weevils in general (another mixed bag, mostly troublesome):

A weevil is any beetle from the Curculionoidea superfamily. They are usually small, less than 6 millimetres (0.24 in), and herbivorous. There are over 60,000 species in several families, mostly in the family Curculionidae (the true weevils). Some other beetles, although not closely related, bear the name “weevil”, such as the biscuit weevil (Stegobium paniceum), which belongs to the family Anobiidae.

Many weevils are damaging to crops. The grain or wheat weevil (Sitophilus granarius) damages stored grain. The boll weevil (Anthonomus grandis) attacks cotton crops. It lays its eggs inside cotton bolls, and the young weevils eat their way out.

Weevils are often found in dry foods including nuts and seeds, cereal and grain products, such as pancake mix. In the domestic setting, they are most likely to be observed when a bag of flour is opened. Their presence is often indicated by the granules of the infested item sticking together in strings, as if caught in a cobweb. (Wikipedia link)

My kitchens in several states have been afflicted by grain weevils (and, more often, grain moths).

So much for mile-a-minute, which has the especially threatening property of surviving frost — which sets it aside from the possibly even more invasive kudzu. Kudzu is both attractive and useful, but it’s also “the vine that ate the south”. From Wikipedia:

Kudzu (… Pueraria lobata, and possibly other species in the genus Pueraria …), also called Japanese arrowroot, is a plant in the pea family Fabaceae, subfamily Faboideae. It is a climbing, coiling, and trailing vine native to southern Japan and south east China. Its name comes from the Japanese name for the plant, kuzu …, which was written “kudzu” in historical romanizations. Where it occurs as an invasive species, it is considered a noxious weed that climbs over trees or shrubs and grows so rapidly, it kills them by heavy shading. The plant is edible, but often sprayed with herbicides.

… Kudzu was introduced from Japan into the United States at the Japanese pavilion in the 1876 Centennial Exposition in Philadelphia. It is now common along roadsides and other disturbed areas throughout most of the southeastern United States.

Kudzu in bloom:


And kudzu doing its mischief, in this case, consuming a house:


Kudzu has manifold uses: controlling erosion, (as a legume) enhancing soil; as a high-quality forage plant for animals; in fiber art and basketry; as a medicinal herb. I’ve grown it in pots in California. Still, like mile-a-minute, it’s scary.

One Response to “Vining menaces”

  1. Japanese knotweed | Arnold Zwicky's Blog Says:

    […] I look at invasives: recently, on privets and tumbleweed, and a bit earlier on monstrously invasive vines —  kudzu and mile-a-minute. Today, thanks to a piece in the 7/5/14 New Scientist (“Let […]

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