Saturday, September 7, 2013

The 2013 Deer Fly Season Has Ended

I have to admit that I was not very diligent about going out and trapping deer flies every day this season.  One reason for this is that I was out of town for several stretches this summer, and other days I stayed inside because it was raining (we had a lot of rainy mornings this summer).  But the biggest reason for my inconsistent trapping efforts is because there were relatively low numbers of deer flies this season and so I didn't always get motivated to go out trapping.  I kind of wish they had been worse so that I would have been more motivated to go outside and trap them.  (Oh my goodness, did I really just say that?!?)  For instance, Fly Trapper (see the comments he has left on some of these posts) was very very dedicated and determined to trap every deer fly that dared to exist on his property this season.  Fly Trapper lives in the same county as I do.  I applaud his efforts!!  I, on the other hand, did not match his dedication this year.  Naughty me!!  I promise that next season I will go out trapping every day regardless of how low or high the deer fly numbers will be.  I hope I didn't make next year's numbers big by allowing those pesky deer flies to breed while I wasn't trapping them.  I guess I'll be paying for it next year.  I'm also predicting that the wet conditions this year are going to yield a huge juicy crop of fierce deer flies next season.  So I'm guessing we'll all be trapping lots and lots of deer flies in 2014.  (I hope I'm wrong!)

In any case, below are my numbers for this year.  While the total number is not a good reflection of how the season went (because I skipped so many days), you can still, nonetheless, see the trend of how many deer flies were around at each stage of the season.  This season surely lasted a long time.  Remember, I spotted the first deer fly on June 16, but didn't start trapping until July 8 (see previous post).  And yet I was still catching deer flies as late as Aug 28.  So while the numbers were lower on any given day this season (again, I believe that is due mostly to the fact that last season was so very very dry), the length of the season certainly wasn't shortened.

And the deer flies that did exist this season seemed so timid compared to all previous seasons.  I don't know why.  I continued to be able to be outside and not be bothered by a single deer fly all season.  But when I'd go out trapping with my umbrella, I would get significant numbers of deer flies trapped.  Much to my surprise most days, because, like I said, they never came out and attacked me this year whenever I was out and about.  Very strange.  Again, that's why I often felt unmotivated to go trap them.  But I won't be fooled next year.  I'll go trapping even if I think there are none of them around!

Until next season, happy end of deer fly season 2013!!

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Saturday, July 27, 2013

Our Deer Fly Population Is Significantly Lower This Season

Well, folks, this is my first post with actual trapping data from the 2013 deer fly season.  I have had to wait until now to post my data because I didn't have enough data to report until now.  This is due to the fact that the number of deer flies on our property this year is significantly lower than that of any previous deer fly seasons we've ever experienced (this is our 23rd season).  I saw our first deer fly of the 2013 season on June 16,  but it was a full three weeks after that until I saw a significant number of them here.  And even then they didn't seem very bad at all.  Throughout the entire season thus far, I have not observed a swarm of deer flies around our cars when we drive down our driveway.  Usually there is a thick dark swarm of them buzzing around the moving cars, to the point where we have to pause and wait a full minute or more before opening the garage door in order to give them time to dissipate before we drive into the garage.  But that's not the case this year.  This year we barely see any flies at all swarming our cars!  Additionally, I have not even had to wear a hat while I'm playing or working outdoors so far this season.

I hate to jump to conclusions, but I think trapping nearly 13,000 deer flies last season has made a big impact on reducing the deer fly population on our property this season.  I'm not sure what else to attribute this great reduction in deer fly numbers to.  We've had plenty of rain this season.  Nothing has changed on our property or in the surrounding areas.  I'm walking the same areas for the same amount of time for each trapping session as I did last season.  There is just nothing else that I can think of which could be responsible for these low deer fly numbers this year.  In fact, we continue to see very few dragon flies this year, which I would have thought would have resulted in higher deer fly numbers.

So, again, while wanting to not jump to any conclusions before all the data is in and before other explanations are considered, as of now I can't help but restate my opinion that my trapping of nearly 13,000 deer flies last season has made a big impact on reducing the deer fly population on our property this season!!

Here's a look at my 2013 trapping data thus far.  Notice that this season I did not start trapping deer flies until the 23rd day of the season ... the season started on June 16 with my first sighting, and I didn't conduct my first trapping session until July 8 because there just didn't seem to be enough deer flies to justify going out to trap them.  (I am slightly regretting not having gone out to start trapping earlier in the season because now I've allowed those few deer flies time to breed.  Oh well, next year I'll start trapping even when there are only a very few deer flies around.)  Due to my schedule and to morning rains, I was not able to go out trapping every day after I first started, but then I became consistent.

OK, here are the numbers for this season so far:

Now let's compare that to last season's data.  This first chart compares the data from 2012 (in red) to the data collected thus far during 2013 (in blue).  These data have been aligned by date.

However, the 2012 deer fly season started 15 days earlier (first sighting was June 1, 2012) than the 2013 season (first sighting was June 16, 2013).  [Remember, 2012 was the year where spring came very early and was very warm.]  Therefore, another way (and probably the correct way) to compare the data from these two seasons is to align them based on the point of the season (not the actual dates).

Here, then, is a comparison of last year's data to the data collected thus far this year, this time aligned with respect to the point of the season (i.e., days into the season, with day 1 being defined as the day of my first sighting for each season).

Rather interesting, don't you think?  Seems that trapping does indeed cause a significant reduction of the next year's population of deer flies!

So how is your deer fly season going?  Are the number of deer flies you are seeing this year significantly different than what you've experienced other years, or is this season fairly typical for you?  I am very interested in what other observers (and, especially, trappers) in Livingston County, Michigan, and neighboring areas have noticed this year with respect to deer fly numbers.

I will post again when I have data collected for the remainder of the 2013 deer fly season.  In the meantime, happy trapping!

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Sunday, June 16, 2013

the 2013 deer fly season has started in SE Michigan!

Well, what do you know, the deer fly season here has started right on schedule this year ... the very first day of the second half of June.  My husband and I noticed our first deer fly of the 2013 season this evening when we drove to the road to put our garbage can out for collection.  Now, mind you, it was only one deer fly, but one is all it takes to signal the beginning of the season.  Within one or two weeks, their numbers will have drastically increased, making them a total nuisance.  Happily, I have my deer fly trap umbrella and will be ready to start trapping and killing those pesky blood-sucking deer flies.  And, of course, I will be keeping a tally of the number of deer flies I catch and will be reporting those numbers here.

I was happy to see a dragonfly this morning.  Sadly, it was merely one.  Come on out, dragonflies, one of your favorite meals is starting to emerge!


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Friday, June 14, 2013

getting ready for the 2013 deer fly season

I am very happy to report that, unlike last year, Spring here in Southeastern Michigan has progressed according to a “normal” schedule.  The vast majority of the pollen and seeds from trees has landed and the cottonwood cotton has finished flying around and sticking to everything.  The plants all bloomed at the appropriate time and, unlike last year, we’ve had plenty of rain.  However, I have not seen any frogs this year.  We usually see lots and lots of frogs of all sizes.  But so far this year, nothing!  Another thing I haven’t seen yet this year is dragonflies.  I am bummed about this because (1) I love dragonflies, and (2) dragonflies like to eat deer flies.  The dragonflies are always out and flying around in large numbers for several weeks before the deer flies emerge.  So, are both the dragonflies and deer flies going to emerge late this year, or are we going to get deer flies without one of their natural predators around?  I sure hope the dragonflies show up!

I am all set for Deer Fly Season 2013.  My umbrella is in good working condition and I have plenty of disposable gloves, sandwich baggies and Tangle-Trap.  Now all I have to do is wait for the bloodsucking deer flies to show up.  Of course, if they want to skip our area this year, I would be very happy!!  But I don’t think that will happen.

I would love to hear about your deer fly experiences this season.  Has deer fly season started in your area?  Are you attempting to trap deer flies?  If so, how?  (If not, why not?!?!)  How many have you caught?  Please share your stories in the comments section.  We would all like to hear and learn from you.

Here’s hoping your deer fly season is mild wherever you are.  I will definitely periodically post my trapping data for the 2013 Deer Fly Season here in Livingston County once the actual bloodsuckers arrive.


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Saturday, July 28, 2012

the 2012 deer fly season has ended!!!

I am officially declaring the end of the 2012 deer fly season here in Livingston County, Michigan.  Hooray!

This morning was my final session of trapping deer flies this season.  I caught a mere 35 of those blood-suckers, so I'm putting my deer fly trap umbrella away until next season.

After my post on July 6, I trapped an additional 3,318 deer flies during twelve subsequent outings.  Here's the data for that time period.

And now that I have a full season's worth of data (and, thus, more data points), here are the updated charts regarding the effects of temperature and humidity on the number of deer flies caught.

The following chart shows my trapping data for the entire 2012 deer fly season (dates with no data bars are days when I did not go out to trap deer flies).

Was it all worth it?

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Wednesday, July 18, 2012


I've received numerous questions and comments from folks regarding various aspects of trapping deer flies, so I thought I would devote today's post to addressing those questions and comments.

The Umbrella

The only umbrella I've ever used for my umbrella trap is the black-and-white umbrella pictured in this blog.  I have never tested other colors or patterns, so I do not know if an alternative color or pattern might be better or worse in attracting deer flies.  I chose to use the black-and-white umbrella because I figured it would offer the best contrast for visually broadcasting my movements to the blood-thirsty deer flies who lie in wait for a suitable passer-by.  If you look at commercially available fly traps, you will notice that they tend to consist of a black-and-clear or black-and-white design element for attracting flies.  The rationale behind this design is that the black portions visually mimic (at least to biting flies, such as deer flies and horse flies) the legs or necks of animals, while the clear or white areas of the trap visually mimic the open areas between, say, an animal's legs.  For this reason, I chose to use a black-and-white umbrella.  It offers high contrast (and, thus, high visibility) and it mimics the legs and necks of animals.

The Blue Cups

The only color cups I've ever used are the blue cups pictured in this blog.  I have not experimented with other colors.  I chose to use blue cups based solely on Dr. Russell Mizell's research results (see my post entitled "credit").  While I have not experimented with other colors, I would be rather surprised if other colors didn't work.  That is, I'm guessing movement is the biggest attraction, regardless of color.  Afterall, deer flies are attracted to brown deer and to people (regardless of what color shirt they are wearing).  However, Dr. Mizell's work showed a preference by the deer flies for blue traps, so that is what I went with.  Basically I followed the if-it-ain't-broke-don't-fix-it school of thought.

The Sticky Stuff

The Tanglefoot product that you want to use on your trap is called Tangle-Trap Sticky Coating.  You can see a picture of this in my post entitled "Making and Using the Deer Fly Trap Umbrella".  The Tanglefoot company produces several insect trapping or insect attracting products, each with its own specific purpose (for example, they have a product for trees so that one can trap insect pests that attack trees).  However, you need to use the right stuff ... Tangle-Trap Sticky Coating ... for coating your trap surfaces.  Tangle-Trap is colorless and odorless.  It is not an attractant.  It is simply sticky.  Very sticky!!  I do not use the spray version of Tangle-Trap.  I use the canned version.  It comes in two sizes.  The 8-ounce can contains a small brush attached to the underside of its screwcap lid for applying the product.  The quart-sized can looks like a paint can and does not come with a brush.  I have recently changed from using the 8-ounce cans to using a quart-sized can (more economical).  And now, instead of using the small brush that is supplied with the 8-ounce can, I use a 2-inch foam applicator on a stick (readily available in the paint brush aisle) in order to easily and quickly spread the Tangle-Trap.  I scoop out a small amount (something like 2 teaspoons worth) of Tangle-Trap from its can with a plastic spoon and drop it onto the top of a bag-covered cup.  I then spread the Tangle-Trap onto all surfaces of the covered cup using the foam applicator.  I have purchased Tangle-Trap through Amazon, but it is definitely also available from numerous online sources.

The Motion

While I have never collected data of my own to confirm the necessity of having the trap move, there is plenty of writing out there that says deer flies are attracted to movement from Point A to Point B.  Therefore, setting up a trap (no matter how fancy it might be) that is simply sitting or hanging in your yard is not the best way to go for trapping deer flies.  It might not work at all or, at the very least, it won't work as well as it would if it were in motion.  You'll probably trap horse flies, but not deer flies.  Again, I have no personal data to prove this, but plenty of experts state that you must have motion from Point A to Point B in order to attract (and then trap) deer flies.

The Placement of the Sticky Surfaces

Whatever the design of your deer fly trap is, the sticky surfaces that do the actual trapping of the deer flies need to be at, or very darn near, the top of the trap.  This placement takes advantage of the deer fly's natural habit of swarming around the head of a victim and then landing on the victim's head or ears or face or neck in order to carry out its blood-sucking attack.  The sticky surfaces need to be highly visible to the deer flies and the flies need an unobstructed clear area around and above the trap's sticky surfaces in order to swarm and land ... and get stuck!

Does Trapping Make a Difference?

For me, trapping deer flies in the morning makes a HUGE difference for that day.  I can work or play outside on our property and not see even one deer fly all day.  If I didn't trap the little bloodsuckers each morning, we would not be able to go outside without being swarmed and chased by a big dark buzzing cloud of them.  After trapping deer flies in the morning, I don't start to notice deer flies again until the late afternoon or early evening, and then only in small numbers.  It takes some time for other deer flies to notice that there is a "vacant" territory around our house and then, once the word gets around, they backfill the vacancy with their presence.  Thus, by the next morning, it's time to trap deer flies again.  And so I do.  And again I have another deer fly-free day to enjoy outside.

How Long is Deer Fly Season?

In the 22 years during which we have lived on our property here in Livingston County, Michigan, deer fly season has always been eight weeks long ... from mid-late June to mid-late August.  The 2012 season got started a bit early here (the deer flies were very noticable during the first week of June on our property), but I think the season will still be a total of eight weeks in length.  We'll see what happens, but I'm guessing (or, at least, really really hoping!) that the 2012 season will be over by August 1.  Individual deer flies live for only 3-4 weeks.  I don't know if our season is typically eight weeks long because adult deer flies keep emerging every day for four weeks, or if because a crop of adults emerge during week #1 and then another crop (a different species) emerges during week #4.  In either case, the eight-week length of our deer fly season has been very consistent and predictable over the past 22 years, regardless of weather conditions or how many deer flies we have during any given summer.  We are already noticing that this season is approaching its end, because during the past week I have "only" caught 150-250 deer flies each day.  Hooray!  Serenity now!!

What Else Will You Catch?

Using my Deer Fly Trap Umbrella on our property has resulted in the virtually exclusive trapping of deer flies.  I caught one horse fly this year (we have very few horse flies to begin with) and two dragonflies (I felt bad about that because I love dragonflies and also because they are natural predators of deer flies).  Other than those three "accidents", I have caught nothing but deer flies (as of this posting I have caught 12,500 deer flies so far during the 2012 deer fly season here in Michigan).

I'll be posting my final trapping data for the 2012 season once the deer flies are completely gone.  Like I said, I'm predicting that will be by August 1.  I hope nature doesn't prove me wrong!

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Thursday, July 12, 2012

deer fly breeding grounds in our area

I'm posting three pictures today to show you a little bit about what our property and the surrounding areas are like.  This will give you an idea of the type and extent of deer fly breeding grounds that exist in our area, and will show you where I walk when trapping deer flies with my umbrella trap.

This first picture shows a zoomed-out view of our area.  The small circle in the middle indicates our homesite.  The large outer circle marks a one-mile radius around our homesite.  According to Russ Mizell's website (see my post from July 9, 2012), female deer flies will travel up to one mile from their breeding grounds in order to obtain a blood meal (i.e., in order to come and bite you!)  As you can see in this picture, our area consists of both farmland and wooded land.  There are plenty of corn fields and soybean fields around, and decent-sized cow farms.  You can also see there are plenty of wetlands in our area (perfect for producing crops of deer flies).

This picture shows a zoomed-in view of our property.  As you can see, we are surrounded by woods and are very close to wetlands.  Our home is situated within a clearing that is approximately one acre in size.  It is not completely cleared out, as we purposely left several islands of trees around the yard.  Our driveway (which is 1100 feet long) winds through the woods.  Our woods are a mix of scotch pines that were purposely planted in the 1950's (well before our time!) for a Christmas tree farm and hardwoods -- several types of oak, maple and cherry trees, lots of hickory and sassafras, and some quaking aspens, cottonwoods, elms, and others.  And, of course, lots and lots of brush and understory growth of all kinds, including plenty of russian olives, wild berries, wildflowers, virginia creeper, and the dreaded poison ivy.

When I go out each morning to trap deer flies with my umbrella, I take a slow stroll around the cleared areas of our property, gently twirling the umbrella as I go at about one revolution every two seconds (as determined by the super scientific one-mississippi-two-mississippi method).  I walk down our driveway, then I walk along a little bit of our road frontage (I go about 30 feet on both sides of the driveway), then I walk back up the driveway and then I take a meandering drunkard's path all around our yard.  I walk the perimeter of the house, the perimeter of our yard, and then here-and-there around the yard.  Once I sense there are no more deer flies to catch that day, I stop and do my counting.  The entire process (from prepping the trap to disposing of the trapped flies) takes one hour.  I estimate that I stroll something like 2/3 of a mile each morning doing this.

And then, as I've stated previously, I am able to enjoy the outdoors for hours without being bothered by deer flies.  I don't start noticing them again until the late afternoon or early evening.

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Monday, July 9, 2012


I want to use today's post to give credit to Dr. Russell F. Mizell, III, Professor of Entomology at the North Florida Research and Education Center (a unit of the IFAS Extension of the University of Florida).  It is his work upon which my deer fly trap umbrella is based, and it was his website about his Trolling Deer Fly Trap that inspired me to make the umbrella trap in the first place.  Here is the link to his excellent and informative website.

Friday, July 6, 2012

I've trapped 9,521 deer flies in just the first 29 days of the 2012 deer fly season!

I'll be posting my final tally of trapped deer flies at the end of this deer fly season, but for now I want to share the results I've obtained during the first four weeks of the season.  I've been having a great deal of fun catching deer flies each morning on our property, and the first 29 days of this deer fly trapping season have indeed been very productive and rewarding.  At this rate, I will have trapped 10,000 deer flies after just two more days of strolling around with my umbrella trap!

The 2012 deer fly season in Livingston County started early, in keeping with the rest of nature this spring.  I wasn't sure what to expect with respect to the number of deer flies that we might see this year, given that our Winter was the-Winter-that-wasn't and that Spring was early and hot and dry and breezy this year.  And certainly the Summer of 2012 has gotten off to a very dry and scorching start.  But none of that has deterred the deer flies!

So I pulled out my deer fly trap umbrella on June 8 and got down to business.

Here is a table of the data I've collected during the first four weeks of this deer fly season (June 8 to July 6, 2012).

Here is a chart of the number of deer flies caught each day.  Notice the spike (676 deer flies) that occurs on July 5th.  Earlier that morning (around 4:15 AM), we finally received some very long overdue rain.  And it was a pretty good downpour.  Not enough to turn the brown grass green or make it feel like something other than dry straw, but I guess it was enough to excite the local deer fly population!

Here are two more charts.  The first chart plots the number of deer flies caught vs. temperature.

The second chart plots the number of deer flies caught vs. % relative humidity.

In a later post, I'll describe and show pictures of our property and indicate exactly where I walk when trapping deer flies and will explain how long I walk around during each outing.  I'll also explain a bit about, and will show pictures of, the area in which we live in order to give you an idea of the type and extent of deer fly breeding grounds that are around us.

Don't forget to check back in about four weeks (deer fly season is usually eight weeks long) in order to see my final tally.  Will I trap 15,000 deer flies?

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Thursday, July 5, 2012

making and using the deer fly trap umbrella

In this post, I’ll walk you through the steps of making and using the deer fly trap umbrella.  In addition, there is a video I made in 2011 about my deer fly trap umbrella.  The video demonstrates how to assemble the trap and shows it in use.  Here is the link to that video:

Deer Fly Trap Umbrella Video

The trap is simply a black-and-white umbrella that is adorned with blue plastic cups.  The alternating black and white panels of the umbrella make the trap an irresistible visual stimulus for deer flies (which are strongly attracted to movement) while I walk around with the umbrella, rotating it as I go.

Each cup is attached to the umbrella with four twist ties evenly spaced around the perimeter of the cup's rim.

Here is a view of the current configuration of my umbrella with four cups attached.  These fixed cups stay securely attached to the umbrella and do not need to be removed or replaced.  The four loose cups that you see in the lower left-hand corner of the picture are used to support the sticky surfaces that trap the deer flies that are attracted to the umbrella.

This is the product I use to create the sticky surfaces that do the actual trapping of the deer flies.

Tangle-Trap is indeed very sticky, so I put on a pair of nitrile gloves before preceeding any further.

I cover each loose cup with a plastic sandwich bag.

The sandwich bags allow me to create a disposable sticky surface, so that the disposal of trapped flies is quick and easy and clean (you'll see that further down in this posting).

I tuck the extra length of each bag inside its cup.  This prevents the bags from blowing off the cups after the loose cups are placed onto the umbrella trap's fixed cups.

The bag-covered cups are then evenly and thoroughly coated with Tangle-Trap.

I coat the tops ...

... and the entire side surfaces of the cups.

Once the Tangle-Trap coating has been applied to the bags, each coated loose cup is placed over a fixed cup on the umbrella, with the excess bag length tucked inside the coated cup.

Each coated cup is gently pushed down until it is firmly seated atop the fixed cup.

Here is a picture of the umbrella trap all set to go with four coated bag-covered loose cups seated upon four fixed cups.

Once the umbrella trap is set up, all I have to do is walk around for a while and twirl the umbrella.

This is a picture of what I trapped after walking around for 15-20 minutes.

In order to get rid of the trapped deer flies and the used sticky bags, each loose cup is lifted from the trap (I use one hand to push down on the fixed cup in order to avoid undue stress on its attachment points) ...

... and the bag (with its attached flies) is removed from its cup and disposed of.  The loose cups are replaced on the trap for storage (there is no need to dispose of them) until the next time I use the trap.

Because I love data, I count the number of trapped deer flies before I dispose of the bags.  I actually do the counting while the bags are still on the cups, but here I have a bag placed over my gloved hand in order for you to easily see the trapped flies.  This picture shows over 40 flies were trapped on one side of this bag alone.

In order to neatly dispose of the sticky trapped deer flies, I simply turn each bag inside out ...

... and then fold it in on itself ...

... numerous times ...

... until I've created a neat little compact ball ...

... that can then be easily disposed of.

In my next post, which I intend to publish within the next few days, I will present the data I've collected so far during the 2012 deer fly season here in Livingston County, Michigan.

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