Thursday, April 12, 2012

Invasive Honeysuckle and Ticks

Lone star tick- Amblyomma_americanum
Do you want to know how to give a tick a "nervous tic"?  Try cutting down invasive bush honeysuckle.  It turns out that this obnoxious arachnid is found more commonly and is more commonly carrying disease where there is a lot of the bushy invader.

Deer and other small mammals are frequently said to be the intended "natural" victims of ticks, a concept supported by their common names of "deer and dog ticks" as well as" lone star".  We humans are supposedly incidental victims.  (Try telling that to the ticks on Bull Creek.  In spite of spraying, I pulled 30+ off my editor after she spent an afternoon pulling garlic mustard.)

A report from Washington University reported in describes how deer are bringing ticks to us in more urban areas.   It appears that deer favor bedding down in bush honeysuckle.  The large draping branches can grow 18 feet tall with stems 4 inches in diameter.  They tend to grow in dense tangles, giving deer safe and luxurious overnight accommodations.  In addition, they leaf out before other shrubs in the spring and retain their leaves through the fall, providing a longer term habitat.

Bush Honeysuckle
Bush (a.k.a. Amur) Honeysuckle is a native of temperate Asia, although it is said to be endangered in Japan (we should be so lucky).  It has escaped and thrived in the eastern United States.  A drive anywhere along the highways around St. Louis and north along the Mississippi in the summer features a constant roadside wall of these luxurious bushes with their bright red berries.

Hard ticks (Ixodidae) can carry Rocky Mountain Spotted Fever, Lyme disease and Ehrlichiosis.  Not only do the bush honeysuckle lure deer and their ticks in toward civilization, but they increase the percentage of ticks carrying disease.
"...the density of white-tailed deer in honeysuckle-invaded areas was roughly five times that in areas without honeysuckle and the density of nymph life-stage ticks infected with bacteria that cause human disease was roughly 10 times higher."
In addition to giving you a great case of the heebie-jeebies, the article in has a lot of interesting details on how the studies were done.  If you want to understand how there were "5,000 nymphal ticks within about a three-meter radius of where we put that trap down," this article is for you.

Some facts to impress your friends:
  • Ticks are not insects but belong to the arachnid family like spiders and scorpions.
  • The first instar emerging from the egg has only 6 legs while the second and third (adult) have 8 legs.
  • Only the female lone star tick has the spot on its back.  Its name is Amblyomma americanum-  so think patriotic thoughts as you pull it off and crush it.
If we didn't have enough concerns with invasive species, this raises a further issue with public health.  We who live in the outdoors know to spray vigorously and do rigorous tick checks.  The suburban population has to recognize that ticks are coming in to meet them.  The reports of possible Rocky Mountain Spotted Fever in St. Louis just emphasize the need to control invasive bush honeysuckle.

- Tick species, their range and diseases are at this CDC site.
Missouri Tick Picture Gallery
- Identification and control measure information from
Missouri Extension, Missouri Department of Conservation  and the CDC are on line. 
- A pamphlet,  Curse of the Bush Honeysuckle, showing you how to identify the plant, is available at or from the MDC office or Conservation Nature Center.

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