The $5 Deer Fly Trap

Here's the deer fly trap I made for about $5.  I found a large blue ball at Walmart for $2.99 (the ball is maybe 2 foot diameter), constructed a twine harness, which I painted blue to retain the effect of the solid color that deer flies are attracted to, and suspended it between two small trees so that when the wind blows, the trees sway and the ball with them (that supplies movement, which attracts flies).  Finally, I coated the top with sticky Tanglefoot.  I already had supplies of the blue paint, twine, and Tanglefoot, so the trap didn't cost much. 

It works! After only three days, there are 30 deer flies trapped by the ball, and not one deer fly swarmed me while at the garden for the first time in weeks. Success!  

The trap was also catching black flies. Yes!!! As far as I could tell, no beneficial insects were getting trapped (like butterflies).   So this trap seems to be effective.  I also checked a couple of small mosquito traps I made with plastic soda bottles, brown sugar, and yeast, but these do not seem very effective so far, possibly because too much liquid was in the bottom. When the yeast started creating bubbles, it just foamed up and blocked the opening.

Mission Impossible: Kill the Flies and Mosquitoes

There are WAY too many deer flies and mosquitoes at Eklund Garden. This is a very common complaint of visitors, especially the non-hiking ones. The Nells Rock area swarms with them because of all the swamps. The vernal pool below Eklund Garden teems with salamander larvae precisely because the baby salamanders have so many mosquito larvae to eat. This being a garden for native species -- not just native plant species, but native animals species as well -- it would be wrong to spray toxic pesticides to kill off the nuisance species.

So the challenge is to try to reduce the number of swarming deer flies and mosquitos without eradicating them from the vernal pool and without poisoning the environment or hurting other insects like bees or butterflies. What we are looking for are some kind of traps that are inexpensive and do not require electricity.

CHALLENGE #1  DEER FLIES.  In July, simply pulling a car in the parking lot results in a dozen deer flies swarming the car before you even get out. Bug sprays like DEET do not help. So the deer flies will be the priority.  In doing some web research, it appears that deer flies are attracted to:

• Carbon dioxide
• Movement
• Solid colors, especially blue or black
• Heat

This would explain their attraction to my blue car as I pull in the parking lot. It's a solid color, warm, exudes carbon dioxide, and is moving. There are various commercial traps that make use of these attractants, usually costing several hundred dollars each. The Horse Pal is an example: http://www.bitingflies.com/.  The flies are attracted to the solid object, land on it's "back", then fly upwards into a trap. This looks like something that would get stolen. For homemade traps, a large solid blue or black object that moves in the wind and is covered with sticky Tanglefoot is another option. 

There are also some lower cost options, such as a bait bag trap, which uses a smelly bait to attract flies. Although designed more for biting houseflies, reviewers say they also trap deer flies. The trap is under $20. 

CHALLENGE #2 MOSQUITOES.  I don't think there is any way to really get rid of all the mosquitoes, but if the numbers could be reduced to more tolerable levels, that would be a significant improvement. Mosquitoes are also attracted to CO2,  Here's one low-cost type of trap made from a soda bottle and using a mixture of sugar water and yeast in the bottom to create CO2 as an attractant: http://www.youtube.com/watch?v=pNjyLRQutXs. Maybe we could have a line of these between the garden and the pond. 

Another tactic is to entice females to lay their eggs in a container of water and then kill the larvae. That can be tricky, because if you don't kill the larvae promptly, the traps just become breeding tanks. 

Full Bloom!

This is the best year so far for the main bed at Eklund Garden.  A reduction in the winter vole damage and plenty of rain through June really helped things along.  The garden is teaming with butterflies, bees, and hummingbirds. Enjoy!

Garden phlox, bee balm, and rudbeckia

Swallowtail on purple coneflower (Echinacea) 

Butterfly on bee balm

Garden phlox

  

  

Rudbeckia - brown eyed Susan

Gailardia  or Blanket Flower

Purple coneflower

 

 

 

 

Soil Analyses

Click to enlarge

Here are the analytical results for three soil samples taken at Eklund Garden. One was taken in the main bed, one back by the Wild Ginger, and another in the Marble Bed, which has plants requiring a higher pH.  I was concerned the pH might not be high enough in the latter bed, but discovered it was fine, but the nearby Ginger bed is too neutral. The main bed also needs some lime. 

The beds could also use more fertilizer, but the surprise was the high phosphorus level in the two back beds. I suspect the leaf compost I've been adding is the source of that, since those beds had a LOT of compost added last fall. Those beds also had "very high" levels of organic matter. The plants there have been doing much, much better this year due to the addition of the compost.