Tick-Borne Disease May Surge in 2012

Northeasterners may very well see a spike in tick-borne disease during this spring and summer, but not because of the non-winter we’ve had.  The numbers of blood-seeking, disease-infected black-legged nymphal ticks will be due to a series of events that began with the acorn crop of 2010.

OLYMPUS DIGITAL CAMERA You may recall having to rake, and rake, and rake acorns off your lawn  in 2010. It was a bumper acorn crop that led to an increased white-footed mouse population in 2011. More food equals more mice. Not only are mice the preferred host for Ixodes scapularis – black-legged ticks – but mice are really good at transmitting Borrelia burgdorferi – Lyme disease – to ticks. Actually, mice are better at infecting tick larva than other tick hosts such as deer, birds, squirrels, chipmunks, fox and opossum. More food equals more mice equals more disease-infected tick larva.

This surge in 2010 was followed by very few acorns in the autumn of 2011. Since acorns are a major forage food of white-footed mice, fewer acorns equals fewer mice. Fewer acorns last autumn also led to particularly heavy deer browsing of ornamental plants, shrubs and trees and extremely persistent squirrel marauding of bird feeders during the autumn of 2011 and non-winter of 2011-2012, but back to mice and ticks.

Ticks need blood meals in each of their three life-cycles. Tick larva, the one-year olds, hatch free of disease but become disease transmitters after feeding on a diseased host. Larva drop off hosts after feeding and grow into nymphs. Tick nymphs, the two-year-olds, feed on hosts, drop off, and grow to adults which feed on hosts to allow them to reproduce what will become tick larva. The larval ticks of 2011 will become the nymphal ticks, which are as small as a poppy seed, of 2012. Nymphs will seek out blood hosts from May through July. With fewer mice available as hosts, nymphs will seek other hosts. To a hungry nymphal tick, people, dogs and cats are just as attractive as any mouse.

I heard Dr. Richard S. Ostfeld, from the Cary Institute of Ecosystem Studies in Millbrook, NY, explain this during his presentation at New England Grows in February. Ostfeld’s and colleagues’ work of more than two decades is also the focus of the article, Lyme Disease Surge Predicted for Northeastern US: Due to Acorns and Mice, Not Mild Winter, in ScienceDaily.

One aspect of Ostfeld’s work I found intriguing was his research on host permissiveness – analysis of where hosts travel, what they eat, how many ticks they support, and how well hosts transmit Lyme disease to black-legged ticks. Ostfeld’s group caught small hosts, kept them until they were free of ticks, re-inoculated them with larva (remember the larva are born disease-free), then tested the number of ticks that survived and were infected with Lyme disease.  Ostfeld reported mice as the most efficient at transmitting Lyme disease to ticks. He said 92% of ticks from mice were infected, as were 55% of ticks on chipmunks, and just 4% of ticks on opossum. He listed percentages of infected ticks from other mammals as well, but mice, chipmunks and opossum were the three that stood out to me.

Ostfeld explained that grooming has a lot to do with the number of ticks that survive on hosts. Apparently opossum are very good at killing ticks while grooming. Mice are not. On the other hand, Ostfeld noted, mice are very good at surviving in the fragmented environments humans have created by building homes and communities in what was formerly forest or meadow.

OLYMPUS DIGITAL CAMERA My experience in south-central Connecticut matches what Ostfeld outlines. Tons of acorns in 2010, tons of mice – many in the house – during the 2010-2011 winter. No acorns in 2011, and few mice in the winter months of 2011-2012. Ostfeld also said to expect increased adult tick activity during mild winters. Adult ticks become active and seek hosts when temperatures are a bit above freezing. During a wooded walk on a warm February 2012 day my camera caught this little beauty crawling on my pants. I found two other adult ticks doing the same. Adult ticks can also transmit disease, but are less likely to do so than nymphs. Needless to say, a tick check followed my hike.

We cannot completely avoid ticks while living in the Northeast, and gardeners, by the very nature of what we do, are at high risk of becoming a tick host. Tick numbers are highest in forest interiors, second highest at the edges of wooded or shrubby areas, and lower in cut lawns. While doing any outside activity it’s advisable to wear light colored clothing so you can more easily see and pick off any ticks and the tiny nymphs. While hiking or gardening it’s best to wear long-sleeved shirts and long pants tucked into your socks or boots. How many gardeners actually dress this way in the heat of summer? Certainly not me. Therefore it’s really important to make a full-body tick check part of your daily routine. Finding and removing ticks from your skin early lessens the likelihood they will transmit disease to you.

Garden thoughtfully … and remember those daily tick checks,

Joene

Read more about tick habitats:
Lyme-ticks thrive in Japanese Barberry thickets and More on the Japanese Barberry-Lyme Tick Connection

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March 2012 Blooms in Connecticut

What a glorious few days … warm temperatures, strong sunshine, and blooms popping out all over. Time for spring bulbs to shine if they can escape the creatures so active in my Connecticut gardens.

Voles have managed to find most of the crocus I’ve planted. I imagine them gorging on crocus bulbs till full then happily transporting any unconsumed bulbs for storage elsewhere along their tunnels.  I’m sure they giggle at me under their vole breadth as they rearrange my crocus. I now have single bulbs  blooming here and there in places I never intended them to be. So much for planting in groups! I once had a beautiful stand of crocus planted on either side of my front steps right where they were most noticeable from the front door. Used to, until the voles ate their share and rearranged the rest.

Last autumn – on the promise of vole-resistance – I purchased Tommies, Crocus tommasinianus. I don’t yet know if they are truly vole-deterring or if my vole population declined because of no snow or the fox that found my front yard so appealing last summer, but the Tommies are blooming exactly where I planted them. These are ‘Ruby Giant.’

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For many of the previous years my Tete-a-Tetes, one of the earliest blooming narcissi, were visited by a hungry deer just as they began to poke their fresh green shoots out of the ground. I’m sure the deer, who are not supposed to like narcissi/daffodils, were just as anxious to see greenery as I. Nonetheless, when I found my emerging Tete-a-Tetes with their tops chomped off, I hoped they caused the four-hooved forager to have an upset tummy.

Here’s what they looked like exactly one year ago.

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This year, the garden idea fairy bonked me in the head with the old, rusty pitch fork remnants I have here and there. The head bonk worked. I came up with this method of protecting the Tete-a-Tetes and so far, so good.

These Tete-a-Tetes may be blooming in a pitch fork jail, but they are doing so with all leaves intact.

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Today is Garden Bloggers’ Bloom Day, a celebration of shared blossoms from across the globe, a garden party hosted on the 15th of each month by Carol at May Dreams Gardens. You can visit there to see what’s going on in Carol’s garden and find links to all the garden bloggers who share their gardens with the world today. If you need a pick-me-up this is the place to find one.

Garden thoughtfully,

Joene

Digiprove sealCopyright secured by Digiprove © 2012 Joene Hendry

Native Plants for Connecticut Gardens

Connecticut gardeners have another opportunity this week to learn more about landscaping with native plants, shrubs and trees. The UConn Garden Conference on March 16, 2012 is one (click on the highlighted link to learn more). Another is at the monthly meeting, Thursday, March 15, 2012 of the Connecticut Horticultural Society when landscape designer Larry Weaner will discuss how to use Connecticut’s native plants to create beautiful, low maintenance landscapes that fit well into the local environment.

His talk, “At Home with Natives,” promises to be another lesson in planting the right plant in the right place for entrance areas, screening and sloped areas, woodland gardens and residential meadows.

Read more about Larry Weaner and how to get to Emmanuel Synagogue in West Hartford by 7:00 pm on March 15, and be sure to bring a $10 donation if you have not yet become a member of Connecticut Horticultural Society.

To bone up on the topic of native plants visit Native Plants & Wildlife Gardens. This blog is a great resource for any gardener or naturalist interested in learning more about native plants and how they work in the environment. It covers current issues and basic information that will help you have a good grasp of the issue before hearing Larry Weaner speak.

OLYMPUS DIGITAL CAMERA To read more about two good resources on native plants in general click on, Make a Difference. Plant Natives, which highlights Doug Tallamy’s book Bringing Nature Home, and On The Bookshelf: The Green Garden: A New England Guide, which reviews Ellen Sousa’s book on planting natives in New England.

Digiprove sealCopyright secured by Digiprove © 2012 Joene Hendry