IOP 2020 Field Research Report

2020 Ixodes Outreach Project Report

Field Research Report 

In 2020 the Ixodes Outreach Project staff conducted two active field research projects in Carlton County, MN.  Our first was a typical tick drag, where our lab staff pull a weighted cloth through a predetermined area, called a transect, while walking a measured path.  Every 10 meters, the cloth is examined to see if any ticks have grabbed on.  Check out a short video of what a tick drag looks like:

 

We monitored the transect from April through October.  Over all we found 84 ticks and 18 of them were Ixodes scapularis, the tick that can transmit the bacteria responsible for Lyme disease.  The bulk of those I. scapularis ticks were caught between late April and early June, with the peak being the 3rd week of May.

We also experimented with a new tick collecting method, a dry ice trap.  Ticks are believed to be able to sense carbon dioxide exhaled by potential prey.  The carbon dioxide gas released as dry ice melts is thought to be a way to attract ticks searching for a meal.  We tested two different styles of trap, and appeared to have relatively equal success.  Our trapping process was started later in the summer, so we missed peak tick season, but ticks are out until snow falls again.  And, indeed we did catch several ticks in September and October with our traps.  

Two different trap designs

Male Dermacentor variabilis tick caught on tape used to hold trap fabric in place

Next year we plan to experiment with other carbon dioxide releasing methods in hopes of developing an inexpensive trapping method that can be used more frequently and at multiple locations.  Stay tuned in 2021 to see how this project unfolds!

Post by C. Fisher

Tick trapping has a good first season in 2020

Part of the work we do at the Ixodes Outreach Project is monitoring and studying ticks, which involves going out into the field and trying to capture ticks where they live and feed.

This season we experimented with a new collection method, tick traps.  Our traps are simple in design, but seemed to yield good results for their first season.  We unfortunately didn't get them rolled out until a little past peak Ixodes scapularis season, but every time we put out the traps we caught at least one tick of some species.   

Here you see our undergraduate researchers building our traps from small Styrofoam coolers.  We tried two designs, one with holes at the bottom for CO2 to diffuse through, and one with holes near the top.  We wrapped the sides of our top-hole version and created a short "skirt" which flared out from the bottom of the cooler with the same fabric our drag cloths are made from to provide a good grip for our climbing and questing ticks.  For the bottom-hole style we simply set these on top of a square of this same fabric and weighed it down with stones to help prevent it being flipped up by wind.

Once the traps were assembled, they were filled with dry ice pellets, which are frozen CO2 gas.  Other researchers have suggested that ticks can sense CO2 breathed out by potential prey and seem to be attracted to it during questing.

The traps were left overnight (approximately 18-24 hours) in locations were we frequently catch ticks during dragging.

A male Dermacentor variabilis tick stuck to the sticky side of the duct tape holding the fabric to the top-hole trap is shown in this last photo near the edge of the duct tape.

These simple traps are reusable, and fairly inexpensive.  Next spring we hope to have our traps out early in the season and test their effectiveness when questing ticks are at peak activity.  The idea is to continue to refine our trap design and potentially launch a citizen science project where we can provide traps to community members who are willing to help us capture ticks for our research.  If funding and refining our trap goes well, we hope to offer traps to the community within the next year or two.  Stay tuned!

Photos and text by C. Fisher

Remember: Ticks can still be out during the fall!

 Even though the weather is cooling, ticks can still be out during the fall until there is snow cover or days stay below freezing.

Our lab caught a male Ixodes scapularis (deer tick) on our most recent tick drag, and I. scapularis ticks are currently being found on dogs.  So, keep your family and fido closely monitored for tick bites until snow flies!

C. Fisher

The Trouble with Nymphs

Photo provided by David Schmipf

As ticks molt out of their larval phase, they enter their "teens," gaining their seventh and eight legs and, as you might expect from other teenage species, become much more trouble than their larval stage counterparts.

Nymphal Ixodes scapularis ticks are still very small, about 1-1.5mm, although this is a little larger than a larva.  They tend to look like a very small adult female, having a very dark brown or black scutum that covers half to 2/3rds of their back and a pale tan or red brown posterior end.  To the right we have a photo of three nymphs on a 1mm grid and shown above the ticks is a poppy seed for size reference.  On the left we have an I. scapularis nymph, in the middle is a Dermacentor variabilis (also known as the dog or wood tick) nymph and on the right is an Amblyomma americanum (also known as the lone star tick) nymph.

Ixodes nymphs are a little easier to see than larvae, as they have somewhat darker coloration, but the posterior end of their bodies can still be semi-transparent.  And, as you can surmise from their still tiny size, would hide easily under hair or in areas where you can't see or reach without assistance.  This makes them very problematic, because during its larval blood-meal, a tick can pick up pathogens and is able to spread those pathogens on to its next prey.  The Minnesota Department of Health estimates as many as one in five Ixodes nymphs may be carrying Borrelia burgdorferi, the bacteria responsible for causing Lyme disease.  Because Ixodes nymphs are now potentially capable of spreading disease when they feed, they tend to be less picky about their prey and, if they bite a human, they can be easily overlooked and allowed to feed long enough to increase the risk of pathogen transmission like B. burgdorferi, some sources consider nymphal ticks to be the riskiest stage for bites. 

Ixodes nymph season is typically reported as being mid-May through June and then tapering off in July.  However, peak nymph season may vary depending on weather patterns and geographic location.  Finding nymphs in our active tick collection process is a challenge, because they are so small, and because they tend not to be out questing for food as long in the warm seasons as their adult counterparts.  However, when we find more than adults in a given area year after year, we can conclude that the species has taken hold in that location instead of being accidentally carried in on people or animals as they migrate through on their travels.  When a tick species takes a hold and is seen to be actively reproducing and increasing its population in a new area, this helps us get a picture of how populations change, expand and migrate over time.  Also, this information is crucial to understanding the risk of disease emergence in new regions.

Currently, in northern Minnesota we do not find A. americanum ticks, although there are reports of some being spotted in the southern areas of Minnesota.  While A. americanum and D. variabilis ticks can spread other pathogenic microorganisms to humans and domestic animals, neither are believed to be able to cause Lyme disease by the transmission of B. burgdorferi. 

No matter where you enjoy the great outdoors, the adoption of appropriate protection methods to avoid tick bites and conducting thorough tick checks daily are the best line of defense against the spread of tick-borne diseases.

-C. Fisher

The curious case of larva legs

Photo provided by D. Schimpf

Ticks pass through three life stages, well four if you count the fact they start life as an egg.  After hatching, they emerge from the egg as larvae.  

In the Duluth area, we may expect larvae to hatch starting in June and July, depending on when they were laid.  So, we hope that we will soon begin to document finding larvae in our active tick collection activities.

However, larvae are exceptionally tiny and very hard to see with the naked eye.  Fortunately, we do not believe they pose much risk for disease transmission, particularly as Lyme causing bacteria are not thought to be passed from the female to eggs.

If you do happen to see a larva, and you have a magnifying glass or very good eyesight, you may notice that they only have six legs.  This is a curious fact, as ticks are a member of the class Arachnida, which means they are not true insects.  They are more closely related to spiders, than say mosquitos, and would be expected to have eight legs.  

In this photo, we have three larval ticks.  The green lines in the background form 1mm squares, so you can get a sense of just how tiny they are.  The far left is a Dermacentor variabilis, or wood tick/dog tick.  You can tell by the little lines on the bottom end of the tick body.  These are called festoons, and are not present on Ixodes scapularis ticks.  The tick in the middle is an Ixodes, and you can clearly see that it only has three legs on the left side (likely one of the legs on the right broke off during collection).  The larger larva on the right is engorged from feeding, it was pulled from a migrating White-throated Sparrow captured at Hawk Ridge in autumn 2019.

Had these ticks not been caught and used for scientific purposes, if they were able to successfully feed, they would then molt and become a nymph.  Emerging from their first molt, they would gain two more legs for the arachnid class standard of eight legs.  From there they would look to feed again in order to molt (retaining their eight leg status) one last time into adults, completing their life cycle.

-C. Fisher

Ticks, Tick Hunting, Lyme Disease and How You Can Help

Wellness Renaissance interviews Cole Fisher about Ticks, Lyme disease and the Ixodes Outreach Project.  

Click on the image above to read more and access the podcast.

Ixodes Outreach Project "Tick Bank" makes the KBJR-TV News!

See this news release from UMD by clicking here.

 

To watch the KBJR-TV 6 news story click here: 

To visit or Risk Story Map referred to in the news release, click here.

Ixodes Outreach Project Active Tick Collection Week 2

Hello!

Last weekend a member of our team caught one Ixodes scapularis tick on our active collection transect in Carlton Co., MN.  It was an adult female.

Our team also found a large number of both adult male and female Dermacentor variabilis ticks.  While not capable of transmitting Lyme disease, these ticks, also known as dog ticks or wood ticks, can spread other pathogenic microorganisms that can make people and domestic animals sick.  So, be sure to take proper tick-bite prevention precautions when you are out in natural areas.

Ixodes Outreach Project Active Tick Collection Week 1

Greetings all!

This Saturday a member of our team caught two Ixodes scapularis ticks on our active collection transect in Carlton Co, MN; one was an adult female and the other was an adult male.

 Ixodes scapularis is also known as the deer tick, or black legged tick and in Minnesota it is the species primarily responsible for the transmission of the bacteria that causes Lyme disease.


-C. Fisher

WDIO Special Report: Ticks On The Move

WDIO ABC News interviews Dr. Benjamin Clarke, Dr. David Schimpf and Cole Fisher.  Click on images above to read and watch the news story.

UMD News: Tracking Ticks

UMD news reporter interviews Master of Environmental Education student and Ixodes Outreach Project member, Cole Fisher, who is conducting tick and mosquito population research for the Minnesota Department of Health in conjunction with Bolder Lake Environmental Learning Center and the College of Education and Human Service Professions at UMD.

 

To read the full article, click on the image below. 

The Tick Collector; Duluth News Tribune Article

 Click on the image to read the May 8th, 2018 Duluth Tribune article.

The Duluth Tribune interviews Dr. Clarke about his research and his goal to engage the public in tick collection.