Homemade Mantid Feeder Fly Traps

With warm weather and flies abound I made a fly trap that is easy to gather flies for feeding my mantids. Within a few hours of adding fresh bait to the trap it has 3 dozen flies or more trapped inside - as long as it isn't raining. Depending on your area the flies will vary, but my fly traps usually contain house flies, blue bottle flies, horse flies, and others (and all sizes of each).

Update - see my post below for better bait and pests.

Update - The top 6" portion of a 2 liter bottle works easier for the cone, and another works much better for the top lid area to remove the flies. Updates added below in the instructions. Or view my new instructions on building a fly trap from 2 liter bottles.

Using the finished fly trap -

• Remove the fly trap lid and put in your fly bait in the bottom between the side and cone. Bait wise, there are commercial versions available; however, for cheap/free the best results are rotten meat or any fresh animal manure (cat, dog, cow, etc). With all the pets in this house it is easy to put on some latex gloves and drop in some manure (free and keeps litter boxes clean). Then replace the lid.
  
• Put the fly trap in a shady area for best results, and gripping the dowel rod legs press them gently into the ground so the fly trap isn't blown over by the wind.
  
• To collect the flies for feeding unscrew the pill bottle lid and quickly put your feeding bottle over the fly trap opening. Some good bottles are empty 2-liter bottles, large pill bottles, Dmina's feeding bottles, and such. Hold the bottle on the opening with one hand, and with your other hand slightly shake the fly trap to coax the flies into your bottle. Repeat as necessary to fill your bottle.
  
• If you are using the Dmina feeding bottles you can feed your mantids directly with it, otherwise the best option is to chill the flies for a few minutes in a refrigerator and use tweezers to feed them to your mantids.
  
• Tip - if it rains or has been hot for a few days, more fly bait will need to be added for best results (especially with manure as it will dry out and not attract flies)
  

How to make your own fly trap(s), I use two to ensure I have plenty of flies and put them into different areas of my backyard to attract more flies.

Materials Needed -

• 1 quart plastic container (or larger, gallon tub will work even better) - With a removable lid to easily add new bait
  
• 2 liter bottle works great or Screen mesh (I used aluminum mesh and recommend it for the mesh cone if nothing else)
  
• Empty plastic pill bottle or 2 liter bottle works much better
  
• 1/4" or 1/2" dowel rod
  

Tools needed -

• X-acto knife
  
• Scissors (to cut screen mesh)
  
• Hot glue gun with glue sticks
  

How to image of the steps and of the finished fly trap (with a few dozen flies), step instructions follow below refer to the diagrams and finished photo for help (if you have any questions ask)...



Step 1

• Remove the center area from your container lid and hot glue in mesh.
  
• On the sides of the container it is best to cut out a single section and glue in mesh one section at a time completely, so it retains the container shape. I also leave a 2" inch gap between both section ends for stability.
  

Step 2

• UPDATE - a better method is to add the top off a 2 liter soda bottle instead of the pill bottle, the top 6" or so that is shaped like a cone. It allows the flies to come out much easier.
  
• Next take a pill bottle and remove 3/4 of the bottle, leaving only the top portion.
  
• With your scissors remove a small section in the middle of the lid's screen mesh and hot glue the bottle in the container lid.
  
• Then cut out the entire bottom of the container to insert the mesh cone in step 3.
  

Step 3

• UPDATE - A easier method to make the trap cone is to cut the top 6" off a 2 liter bottle and insert it into the bottom of the trap. It gives a quick and easy cone with great results.
  
• It's time to create the screen mesh cone to trap the flies, and allow them to enter the container. This is where the aluminum (metal) mesh is preferred over the plastic type as it is easier to roll into a cone and hold it's shape.
  
• Take a large piece of screen rectangular in shape and roll over one corner.
  
• The cone base needs to be larger than the bottom of the fly trap bottom hole. The top of the cone needs to be 1/2" to 1" at most for best results.
  
• Roll the cone and test fit as best as you can (remove the lid to use both hands) - the top of the cone should top out half to 3/4 of the height inside the trap.
  
• Once you got the cone shaped hot glue the overlapping mesh areas. Also hot glue the cone inside the container from the bottom and trim off the excess cone length from the bottom of the fly trap with scissors.
  

Step 4

• The last step is to cut the dowel rod into three sections for legs, I use about 7" lengths.
  
• Hot glue each dowel rod in a triangle pattern on the outside of the container overlapping it a few inches on the container for best results.
  

I got the original idea, and adapted it for feeding my mantids, from a reprinted vintage article from this website.

Sweet write up...this should be a sticky in feeding section.

Is there any issue with feeding "back yard" bugs? Parasites, health issues?

Dude!... Incredibly useful tool for spring/summer time months. Though I was having trouble understanding the illustrations, I think I'm now understanding it a little better, I'm assuming the flies enter at the bottom?

Yes the bottom they enter. This is a very neat tool for catching flies.

jrh3 said:

Sweet write up...this should be a sticky in feeding section.

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Thanks, glad it helps. I know my mantids have been eagerly filling their guts from all the flies the traps catch.

Moonstonedragons said:

Is there any issue with feeding "back yard" bugs? Parasites, health issues?

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Depending on what insects you feed them it can be, but unlikely. In most cases if the insect makes a bad feeder your mantid will avoid it, eat only the edible parts, or such - and flies are a good source of feeders (depending on mantid size, as they can be little use to some large adult mantid species, but even then are a treat).

Many mantid keepers feed their pets only wild caught insects year round, and others when they are available in the spring/summer such as flies/moths/butterflies. Sure there can be problems, but it is usually a low chance. Seems keeping/raising feeders indoors provides far more risk and possible health affects.

The only thing that seems to be of concern is pesticide/chemical use in the area, as it can be on the feeders and ingested by your mantid. As there are no chemicals used anywhere in my area it is no concern, but if it is in your area you can setup the traps in a more rural/country setting to decrease the risk chances.

LAME said:

Dude!... Incredibly useful tool for spring/summer time months. Though I was having trouble understanding the illustrations, I think I'm now understanding it a little better, I'm assuming the flies enter at the bottom?

Click to expand...

Yes, the flies will climb or fly underneath (one reason it has the dowel legs to keep it off the ground) and enter through the cone. The flies will originally land on the container and search for a entrance to get on the bait. It's said flies can not fly down (only up) so they are trapped once inside. A few may climb out but unlikely - as I know when there have been too many flies to use as feeders, they will eventually pile up dead in the bottom of the trap.

If you have any build question just ask.

Where do you place the fly bait? What is a good fly bait that will attract a good amount of flies?

Where do you place the fly bait? What is a good fly bait that will attract a good amount of flies?

PrayingMantisPets said:

Where do you place the fly bait? What is a good fly bait that will attract a good amount of flies?

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Both answers are in the initial instructions...

Using the finished fly trap -

• Remove the fly trap lid and put in your fly bait in the bottom between the side and cone. Bait wise, there are commercial versions available; however, for cheap/free the best results are rotten meat or any fresh animal manure (cat, dog, cow, etc). With all the pets in this house it is easy to put on some latex gloves and drop in some manure (free and keeps litter boxes clean). Then replace the lid.

Updates --

There are two things I have since noticed/experienced and I am pointing out, better bait/food and pests invading the fly traps.



Food

A improved bait to use in the fly traps is without a doubt, meat. A easy source of meat is any old/expired food from the fridge, for example in the photo above you can see I have been using old Pickle loaf deli meat.

One of the best is old grayed hamburger meat. Or if you are buying meat to put into your fly traps, a very cheap source is cat or dog food - which can be bought for $0.25 a can for cat food (enough to fill 3 traps) - and the cheaper the food the better.

Besides attracting more flies, the meat also lasts much longer than manure (depending on the meat thickness it can last over a week). A rough count of the flies in my two traps was over a hundred, and when shaken sounds like a bee's nest. The feeder bottle had about 50 flies, and after feeding my mantids earlier I had many flies left over.

The traps refill in less than 24 hours, and I have more than enough for my mantids in just a few hours after adding meat bait if it's empty.

* Note - Wild fruit flies can be easily caught in this trap as well; however, you will need to use a fine mesh screen so they can not escape. I use organza fabric on my fruit fly containers without a problem, and is a cost effective solution. A great bait for fruit flies is watermelon, cantaloupe, or bananas (Oh, BANANAS!).



Pests

I originally kept my fly traps directly on the ground, but as time went by I had more pests invade my traps. Common pests that will climb the trap legs are small garden slugs, giant Leopard Slugs, various spiders, ants, beetles, isopods, and others.

There are two pests that can be the most problematic. Ants can be life threatening to your mantids if they are transferred with the flies, so be careful (seems due to their small size they can easily attack and injure/kill a mantid). The other is simply a danger to the fly feeders - spiders. I've had a few spiders in a trap that built a big enough web to snare many flies and block the exit hole I use to get the flies into bottles.

A easy solution is to keep the fly traps in a tub of water, such as a bird bath as I do now. The water has eliminated nearly all pests from entering my traps. If you don't have/want to use a bird bath then put the traps in buckets of water with a few inches of water inside - the flies will easily still enter the trap.

Other solutions -- cover the trap legs in a thick layer of petroleum jelly (should stop most pests), or cover the legs in "bells", see methods to keep squirrels out of bird feeders for other ideas too.

* Note - Once the fly trap is invaded by pests it is best to empty the fly trap and refill it to remove/kill all pests.

Very smart! Thank you for sharing.

Great idea Thomas... thanks for sharing!

I tried a trap of my own and I have tons of flies I used lunch meat as a bait

okay now I have way more than I know what to do with I think its about 50-100

spider_creations said:

okay now I have way more than I know what to do with I think its about 50-100

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Glad you are getting great results too. It is nice to have a great and easy feeder available, at least when it's warm (been in the 30s here again for the lows so I haven't had many yet).

Good thing about too many flies is you don't have to worry about not having enough, they often leave eggs in your traps that can hatch more flies, and the dead ones aren't buzzing around your yard/house (and they also attract other insects to your traps if your interested in things besides mantids - I've had American carrion beetles, various spiders, and other things from time to time in the trap as well).

CosbyArt said:

Glad you are getting great results too. It is nice to have a great and easy feeder available, at least when it's warm (been in the 30s here again for the lows so I haven't had many yet).

Good thing about too many flies is you don't have to worry about not having enough, they often leave eggs in your traps that can hatch more flies, and the dead ones aren't buzzing around your yard/house (and they also attract other insects to your traps if your interested in things besides mantids - I've had American carrion beetles, various spiders, and other things from time to time in the trap as well).

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yeah i hope they lay eggs because i tried  gain on raising fly larva and all was great until some how my dog got to it again he smells the meat so he tries to get it every time   this time i have to watch for that. yesterday it was 97 i little to hot but this summer i will probably see temps over 100

spider_creations said:

yeah i hope they lay eggs because i tried  gain on raising fly larva and all was great until some how my dog got to it again he smells the meat so he tries to get it every time   this time i have to watch for that. yesterday it was 97 i little to hot but this summer i will probably see temps over 100

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If your trap does, very likely if you kept it baited, then the fly larvae/maggots will usually stay in the bait. Just be careful when refilling as they can easily fall out of the trap and will quickly dry out then. I can't say their eggs in the traps lead to many new flies as feeders, but enough to let it be.