Exotic Honeysuckle that is native to Europe is 5 times more likely to harbor deer ticks then other structural habitat in woodlands and fields.....Invasive non-native plants that create monocultures and crowd out natives repress biodiversity and create disease zones for all animals including humans

Invasive Honeysuckle Increase Risk of Tick-Borne Disease in Suburbs

ScienceDaily  — "You don't have to go out into the woods anymore," says tick expert Brian F. Allan, PhD, who just completed a postdoctoral appointment at Washington University in St. Louis. "The deer are bringing tick-borne disease to us.So, it stands to reason that anything deer like, might increase the risk of tick-borne disease for people.

The invasive plant bush honeysuckle, for example.

Yes, that leafy shrub with the lovely egg-shaped leaves on arching branches, fragrant white or yellow flowers and the dark red berries so attractive to birds.
Called bush or Amur honeysuckle, Lonicera maackii derives from the borders of the Amur River, which divides the Russian Far East from Manchuria. Its Latin name honors Richard Maack, a 19th-century Russian naturalist."I've spent a lot of time in honeysuckle," Allan says, "and I can tell you there are deer tunnels through it. So if you get down low, you can actually move through honeysuckle pretty efficiently. And you pick up a lot of ticks while you're back in there."

An interdisciplinary team made up of ecologists, molecular biologists and physicians from Washington University in St. Louis and the University of Missouri-St. Louis tested Allan's suspicions by experiment in a conservation area near St. Louis.

As Allan and his colleagues report this week in the Proceedings of the National Academy of Sciences, 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.

Hard as it may be to believe, given the long chain of interactions needed to get there, the presence of bush honeysuckle substantially increases the risk of human disease.

"But that's exactly what is happening," says Jonathan M. Chase, professor of biology in Arts & Sciences and a collaborator on the project. The big question now, says Chase, who is also director of Washington University's Tyson Research Center, is whether what holds for honeysuckle holds for other invasive plants as well. "This may be something that's occurring quite broadly, but we're really just starting to look at the connection between invasive plants and tick-borne disease risk."

"The deer used the open areas less than the honeysuckle patches and we don't think it's because they're eating the honeysuckle; we think they're using it for physical structure," says Allan. "They like to bed in it because it's the densest thing out there, the best structure in town. No native species comes close to achieving the same density."

Allan and Dutra measured vegetation density by counting how many leaves touched a string between two poles. By this criterion, honeysuckle patches were 18 times denser than patches of native vegetation.

Moreover, Allan says, bush honeysuckle retains its leaves longer than most native species do. It's the first thing to leaf out in the spring and it's the last thing in the understory to drop its leaves in the fall, so it creates structure for a large portion of the year."This includes really important times of the year from the perspective of tick biology," Allan adds. "Larval ticks, the first lifestage ticks, are out from August until October. Come late October, honeysuckle is the only thing providing green cover, so deer probably bed in honeysuckle throughout the larval tick season.

Wherever you find white-tailed deer, you are likely to find ticks, Allan says. Lone star ticks need blood meals to power their metamorphoses from larva, to nymph, to adult and to fatten up for egg laying.They sometimes bite coyotes, foxes and other animals, but their favorite hosts are wild turkey and white-tailed deer.

The team did two assays on tick DNA: one to identify pathogenic bacteria and the other to identify the animal that provided the tick's last blood meal.The results showed that more blood meals were taken from deer in honeysuckle-intact plots.

.Win-Win Ecology?
The irrepressible Allan is more encouraged than not by the new findings.
"We're really simplifying our environment, he says. That's what the diversity crisis is leading to -- humans living in monocultures. That's exactly what bush honeysuckle is, a human-caused monoculture.""But as ecologists like to say, nature abhors a monoculture. Monocultures are unstable, and they often have negative consequences for human health."

"Many studies around the world are showing an increase in the risk of infectious disease as a result of the loss of biological diversity.""It's hard to get people to focus on invasive plants. That's why these invaders are so successful. They're basically more persistent than we are."

"But people are more likely to pay attention when their health is at stake."
"So this may be a case of win-win ecology. Honeysuckle control would benefit native species but it would also benefit human health. I think that's the really encouraging message to have come out of this study. "