# Harvesting HFs from a net cube.



## PhilinYuma (Aug 8, 2009)

Kova

Here's a device which I have just tried and found extremely useful and efficient, but which nobody will make themselves, so I won't say, "next you..." but "next I."

Purpose: Chuck mentions that one way to harvest flies from an enclosure is with a mechanic (not oral!) suction device. I keep my flies in a 12" cube like a lot of people , and rely on the flies' attraction to light to harvest them in a pot. It's a nuisance at best though, especially when you're running low on flies, so I made a mechanical suction device.

Required. A vacuum cleaner and a "dead"vacuum cleaner (see what I mean) I used two uprights and the tubing and odds and ends from the dead one.

The largest of Katt's white topped hexagonal jars -- they have thick, rigid plastic.

A pair of panty hose (of course!) and a rubber band that will fit around the jar.

A large, round, wide mouthed plastic jar that used to contain 6.5 lbs of milk bones. In this case the ID of the mouth of the jar was 4.25"

Method: I connected the live vacuum cleaner's air hose to a narrow thing that housewives clean dust out of unimaginable places. Connected narrow thing to the hose from the working vacuum and inserted it into a hole cut in the side of the big jar close to the bottom. Remember that all of the cuts I made were for exact fitting. If the fit is not exact, you will lose vacuum.

I bored a hole of apropriate size with a hole saw into the middle of the bottom of Katt's jar. "Apropriate size" means that whatever round thing you have attached to the hose cut from the dead vacuum cleaner fits into it snuggly, it will not be glued. In my case it was 1.75" A vial or round medication container with a radius that allows it to fit into the hole in Katt's jar. Remove the lid from the hex jar and replace it with a single thickness of panty hose secured by a rubber band around the jar. There, I'm done!

Operation: I trundled the vacuum cleaner into the bug room and placed the large jar on the floor close to the HF net cage. I fitted the hex jar head first into the big jar, it should be a tight fit with the panty host acting as a gasket. I inserted the round thing attached to the "dead" hose into the bottom of the hex jar.

When I harvest flies, I usually place an old sweater over the zippable side of the cage so that I can work through the arm and lose very few flies. I threaded the free end of the dead hose through the sleeve and through a small area unzipped in the cube and turned on the vacuum cleaner. Bingo! About fifty flies in the jar in a few seconds. Remove hose and zip shut the cube. I now remove the hex jar from the large jar. The flies are a little traumatized by their trip (though the panty hose softens their landing) and it is easy to remove the round thing from the bottom of the hex jar and plug the hole with the medication container (in this case, Wallgreen's Stay Awake for those long weekend parties!), without any escaping.

I now have fifty flies in one jar ready for the fridge after a few seconds of "vacuuming" and I could as easily have harvested half or twice as many. No flies escaped during the process.

I did a small victory dance to celebrate my success.


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## ismart (Aug 8, 2009)

Great thinking phil!  Has this gone smoothly so far?


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## ABbuggin (Aug 8, 2009)

Sounds good. Have pics?


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## massaman (Aug 9, 2009)

alot of extra work just to harvest flies


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## PhilinYuma (Aug 9, 2009)

Well, here it is for AB and the hundreds of members who PM'd me asking for a pic.

The "narrow thing," bottom right, receives the tube from the vacuum cleaner. The hose used to suck in the flies is on the top.

One irritating weakness of this setup is that the combined weight of both jars is less than that of the hose, so I shall probably pour some plaster in there and add some pebbles as ballast.

The flies end up in Katt's hexagonal jar, which is seperated from the big jar by the panty hose. I rmove the jar wiyth the flies and stopper it with the medicine bottle. It is then ready for chilling.

I don't regard this as a lot of work, massaman, but rather a lot of fun.


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## ABbuggin (Aug 9, 2009)

Looks like a lazy man's aspirator if you ask me! :lol: 

jk, glad it works for you.


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## Katnapper (Aug 10, 2009)

Sounds pretty neat, Phil! I'm just not into constructing a contraption like that. I guess I'll just have to put up with a few escapees from time to time, lol. Although phototropism, gathering the excess of the zippered opening around my arm (inserted into the net fly cage... making it kind of like a temporary sleeve cage), and misting the fly cage before capturing them (it helps settle them down) in a rigid plastic jar does help quite a bit.

For me, phototropism offers the greatest advantage in keeping the majority of flies to one side of the cage (the opposite to the zippered opening, of course), when gathering them and when releasing into the target net cage too.


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## PeterF (Nov 13, 2010)

Have you tinkered with this any over the past year?

We have a mini dirt devil http://www.dirtdevil.com/products/details.aspx?id=M08230RED

That kind of thing, but like 20 - 30 years old.

We do have the hose kit for it, and while it a terrible vacuum, I am inclined to try it for this.

My two thoughts (and reason for asking if you have tinkered) are;

It seems like it could be done with less parts (granted, I haven't built one myself, so I can't really say).

As well that I am thinking that down wind of the collecting jar (that is, closer to the vacuum) but still on the fly collector proper, one could have a hole in the tube that is either covered by the hand or a movable sleeve to control the total vacuum pressure on the collecting jar. It may well be unneeded and pointless. Just the thoughts that cross me as I start to think about making my own.


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## PhilinYuma (Nov 14, 2010)

The only tinkering that I have done with it Peter, is to put some ballast in the bottom of the large jar. I have also made a second collection jar for when I lose the first one.  

I just read the thread for the first time since it ended over a year ago. I said then that I was sure that no one would build one and I believe that I was right.

It is one of my most valuable tools. I noticed that Brian asked about whether you can just pop the12" cube in the fridge. Yes you can, but it means stunning all of the flies as often as you harvest them, takes up space and increases the likelihood of accidents, and any accident involving a thousand HF's or BBs is best avoided!

I put it together from what I had at hand, the jars, pantyhose and some parts from a junked vacuum cleaner. It can be used with any vacuum with a standard hose, but building it does require the ability to cut holes precisely enough for "jam fitting" of the vacuum hose parts into the jars and a collecting jar that will fit precisely into the neck of the large one without losing vacuum. It also means that the vacuum can be run at full blast without harming the flies. If something blocks the intake tube, the large jar will simply deform. My first thought was to control the vacuum with a release hole or a more ambitious sleeve (much harder to build than to visualize!), but my setup makes it unnecessary.

I think that your idea of using a dust devil is excellent. The motor on that kind of tool uses brushes, but you could use a rheostat to reduce the power/rotation/vacuum. Dremel used to make speed reducers for their drills before they made variable speed tools, but you may be able to find one or an old sewing machine foot operated one at a thrift store or electrical parts (junk) store. Are they bagless? If so, you will need to find a way of putting them in the freezer.I think that it is a very worthwhile project and shall look forward to your progress with interest.

Another possibility is to try a rechargeable DC car vacuum such as that made by Black and Decker. I bought one for a D in L to pick up stray beads and I think that it might work well if you can find a way to stop the flies from escaping after being suctioned.


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## PeterF (Nov 14, 2010)

I guess the one thing I don't understand, but might need to for my own adaptation, is do the flies get stunned when they hit the pantyhose?

If not (or even if so) how are you closing the collection cup after the vacuum is off but before they escape.

Actually, now that I see the assumption in that sentence. Do you leave the vacuum on while capping the collection jar?

Does the pantyhose expand in the direction of the vacuum, or stay more or less taught across the jar?

I guess I need to decide if I should proceed w/ the dirt devil, or make up something portable...


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