Reflections in Nature: Mites afflict multiflora rose
Several weeks ago, Wes McNett and his wife took my wife and I for a ride on McNett Mountain, where he had been privileged to see young wood ducks leaving the tree cavity where they were born.
On our ride, Wes mentioned that he has been trying to eradicate the multiflora rose bushes from his property. I questioned whether any of his bushes had succumbed to the disease that has been attacking the multifora rose bushes.
While showing me several multiflora bushes that showed signs of the disease, Wes mentioned that he was thrilled that Mother Nature finally was correcting one of man’s many mistakes.
An expensive and back-breaking chore for farmers has been and still is maintaining fences to keep their livestock enclosed. An old saying is that good fences make good neighbors.
Farmers have long been interested in the idea of living fences. Fences without posts or rails to rot out and wire to break, sag or rust is a delightful idea to one who has spent long hours driving posts and stringing and stretching barbed wire each year.
The English used their hawthorn bushes for a living fence; however, the hedge needed to be trimmed.
In Missouri, the osage orange had become the farmers’ answer to a living fence; however, this soon became a problem because the plant’s root system, which sent out robber roots into the fields, stole the fertilizer out of the soil. Osage orange also needed to be trimmed to be an effective fence.
In 1940, tests were done to find a replacement for osage orange and, out of 200 shrubs, the multiflora rose won. The plant occupied less ground, required no trimming, grew on poorer soil than osage orange, had colorful flowers and bore an abundance of berries that turned dark red and persisted throughout the winter months, producing food for wildlife.
The multiflora rose was said to offer little competition to adjacent crops. Soon, it was being furnished to farmers up and down the East Coast.
In the August 1948 issue of the Game News, an article on the multiflora rose stated that by 1943, only 20 miles of rose fence had been planted in all of the United States; however, by 1948, multiflora rose was becoming America’s living fence. During that year, 1,000 miles of plants were set out.
The article went on to say that Pennsylvania alone needed 51,000 miles of multiflora rose.
The 1948 article stated that multiflora rose grows from seed and to a certain extent by layering. However, only under ideal nursery conditions will the seed germinate; therefore, the plant will not spread.
But, they overlooked the fact that birds feed on the berries. Once the hard seed passes through the bird’s digestive system, it is softened enough to permit germination.
As a result of all the planting of multiflora rose in the 1940s, ’50s, ’60s and even into the ’70s, along with the ability to spread, the plant has become an invasive species.
Multiflora rose was imported from Japan in 1866 and used as a rootstock in grafted roses. It became popular and was purposely planted along highways for soil erosion and as a living fence.
I remember taking seedling orders from farmers who were enrolled in either the Game Commission’s safety zone or farm game projects and then, at a later date, delivering the multifora rose plants to them. Before leaving, I always mentioned to these farmers that the plant was good for wildlife.
It wasn’t long before we realized that multifora was extremely prolific, producing over a million seeds each year and also spreading through both the stems and root system. Today, farmers and landowners are trying to rid their lands of the noxious plant; however, it is an expensive and tedious job.
Mother Nature now has stepped in with a disease known as RRD (rose rosette disease), more commonly known as witches broom. The disease Phyllcrocoptes fructiphilus K is caused by an extremely small eriophyid mite, a mite so small that 20 could stand side-by-side on the head of a pin. Multiflora rose is extremely susceptible to this mite disease.
Witches broom is easily identified by the new growth of leaves and stems of infected plants appearing as a deep red and possibly crinkling leaves. Later, the plant produces numerous small succulent shoots growing in all directions, giving the stem a witches broom appearance. After being infected, the plant usually dies within two years.
That’s the good news; however, the bad news is that the mites could spread to cultivated roses. Some ornamental varieties of roses can become affected with RRD, but the symptoms are less severe. Several species of ornamental roses have been inoculated under greenhouse studies, and after 2 1/2 years, they show no symptoms of RRD.
The multifora rose is another example of man’s attempt to improve on nature that ends in disaster.
Bower retired after 34 years as a wildlife conservation officer for the state Game Commission. He has published several books about his experience. Questions and comments may be sent to him at 153 Redington Ave., Troy PA 16947.