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 Velcro hook tape as a larvae containment device 
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Joined: Sat Mar 05, 2011 11:35 pm
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Location: Central Florida, USA
Post Velcro hook tape as a larvae containment device
I've been using Velcro hook tape (not the loop side) as a barrier to aid in preventing black soldier fly larvae from escaping a composter. It's a love/hate relationship that I have with the technique. I love how effective it is; it works by breaking the surface tension of the moisture that allows BSFL to climb smooth vertical surfaces. I hate the issues with adhesion; in such a warm and humid environment the tape is prone to peeling. Of course the larvae exploit every little gap they can find. :roll:

PeteB, who is extremely handy and creative, has a system that is also effective. It uses the concept of an inward/downward facing lip, which makes it necessary for larvae to round a sharp 180ยบ turn in order to escape. Medium and large larvae typically cannot make that turn without losing their grip and falling back into the waste. As with the Velcro method the smallest larvae can defeat it, but they normally stay with the waste anyway. Here are the mechanical barriers used by PeteB (link) and (link)

The Velcro system requires a lot of care to minimize the adhesion issues, but it may be a good choice for people with limited tools or skills who might otherwise adopt Peter's technique. Below are some pointers for anyone who wants to try Velcro.

*You must thoroughly clean the walls of the unit in the area to be applied with alcohol, and prevent any contamination from oils. This means you cannot touch either the cleaned wall or the adhesive on the tape with your fingers/hands.

*Once the backing is peeled away from the Velcro tape, nothing must touch it other than the surface it is being applied to. That can be accomplished by leaving the clear backing (which protects the adhesive) in place and gradually peeling it as you apply the tape.

*Pressure must be applied to the entire surface of the tape immediately after installation. The back of a spoon works for this. If your container is clear you can inspect for air bubbles easily, and work them out with pressure.

*The adhesive should be allowed to cure for at least 24 hours before being exposed to any stresses, moisture in particular.

*If applying the tape to polypropylene or similar plastics, I recommend very gently roughing the composter wall, where the tape will be applied, with super fine (400 grit), or ultra fine (600) grit sandpaper. The surface should not feel rough after sanding, it should only have a hazy or matte look to it. This gives the adhesive on the tape a better surface to stick to. Of course the area must be flushed with alcohol after sanding and before tape application.

*When rounding inside corners, the tape should have a seam/break in the middle of the curve or at a corner. This helps prevent the tape from pulling away from the corner as it expands and contracts with temperature changes.

Even with the care described above, I've seen Velcro failures, however I've found it easy enough to repair. Sometimes I carefully cut out the failed area and replace it with new Velcro, and other times I simply clean the area and reapply the loose tape with waterproof silicone sealer. It may sound like a lot of effort, but after the initial installation I rarely spend more than a few minutes of maintenance in a season.

For my bio-composters I'm currently using Velcro Ultra-Mate tape, which has a rubber adhesive, combined with 3M Primer 94. Both materials are normally sold in large quantities which adds a lot of cost for anyone who wants to make one or two units, which is why I haven't mentioned it. In past I've used Velcro "Sticky Back" hook tape with reasonable success.

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*I'm not an entomologist, and much of what I write about BSF is an educated guess.


Fri Jun 06, 2014 12:36 pm
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Joined: Mon Mar 21, 2011 3:26 am
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Location: Durban, South Africa
Post Re: Velcro hook tape as a larvae containment device
My problem with velcro was simply this: The velcro I used was made from Nylon, and the bin was probably Polypropylene. The two materials had different explansion rates.
Invariably, the adhesive would separate after a few weeks of heating and cooling. Short pieces, ie. lots of expansion joints, was only a partial solution.
That said, this was the only velcro I could find. I'm sure one would have a wider selection in places like the US.


Tue Jun 24, 2014 10:06 pm
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Post Re: Velcro hook tape as a larvae containment device
The Velcro I use is also nylon Peter. I think if we could achieve sufficient adhesion the different expansion rates wouldn't matter too much because Velcro can stretch. I chose Velcro over an inward facing lip because it's easier for DIY types to install, and also easier for my Bio-composter customers to repair. Now that I've discovered the wonders of hot glue I may transition to an inward lip barrier because I might be able to make one that will last for several years.

After years of using Velcro this way I will admit that it usually gets a bit ugly with use, but I have still had satisfactory results. Even with gaps and tunnels that I often don't bother to repair, the Velcro system works adequately. Usually a larva will ascend straight up the composter wall, and attempt to continue across the Velcro instead of turning and "searching" for a gap. Of course very few cross the Velcro surface successfully. If a larva happens to travel straight up to a gap it will probably escape, so if the barrier has gaps that equal 5% of its length I would expect a similar percentage of escapees. I would prefer 100% containment, but I can live with a little less.

When I find the time I'm going to try using hot glue to make repairs to my Velcro barriers. If it works as well as I think it will, I should be able to get close to optimal performance, even it it's not pretty to look at. :D

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Wed Jun 25, 2014 10:09 am
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Post Re: Velcro hook tape as a larvae containment device
Jerry wrote:
After years of using Velcro this way I will admit that it usually gets a bit ugly with use, but I have still had satisfactory results. Even with gaps and tunnels that I often don't bother to repair, the Velcro system works adequately. Usually a larva will ascend straight up the composter wall, and attempt to continue across the Velcro instead of turning and "searching" for a gap.

In retrospect I don't think it's necessarily true that larvae "usually" go straight up without turning. Maybe "often" would have been a better word. It's probably a better guess that with gaps in 5% of the Velcro that 15% of larvae will escape.

I think what I was focusing on when I wrote the previous post was how composters with several gaps in the Velcro still remain at maximum levels of larvae. Of course that is more based on the density of juvenile larvae, and faults in the larva barrier will most effect mature larvae looking for an exit. I don't normally monitor the output of mature larvae, because I'm not feeding them to animals. I simply collect them and protect them through pupation without a lot of thought about what percentage of them I collected.

None of that changes my basic position that Velcro works adequately to contain BSFL, but if one wants to maximize the harvest of mature larvae it's required to mend the gaps and tunnels that form in the Velcro. I'm operating one of my earlier bio-composter prototypes which has a lot of openings in the larva barrier, and I will try to make a video soon showing a repair attempt using hot glue. I think hot glue may be the most effective tool for repairing it.

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*I'm not an entomologist, and much of what I write about BSF is an educated guess.


Fri Jul 04, 2014 8:52 pm
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Post Re: Velcro hook tape as a larvae containment device
Quote:
.....if one wants to maximize the harvest of mature larvae it's required to mend the gaps and tunnels that form in the Velcro.

How about this: Cut a thin strip of acetate sheet and glue it underneath the vecro. It should neaten up your blisters and bubbles ...??


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Sat Jul 05, 2014 5:21 am
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Post Re: Velcro hook tape as a larvae containment device
Thanks Peter. I'm looking into a lip style barrier now that I've discovered hot glue.

Have you had good results with your hot glue test?

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*I'm not an entomologist, and much of what I write about BSF is an educated guess.


Sat Jul 05, 2014 10:51 am
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Post Re: Velcro hook tape as a larvae containment device
Jerry, the jury is still out on the glue. Our nights go down to 50 F, so my lot are almost dormant. The crunch time comes in Feb-March, so you'll probably know before me.
However, from what I have seen, I'm cautiously optimistic. :D


Sat Jul 05, 2014 12:10 pm
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Post Re: Velcro hook tape as a larvae containment device
BTW, grubs can also get over a lipped barrier. If there are enough of them, they build a ramp into one of the corners.


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Sat Jul 05, 2014 12:51 pm
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Post Re: Velcro hook tape as a larvae containment device
Yes, I've seen that. I think the original round BioPod did the best job of containing larvae with it's round contour and inward lip. Even then I saw an occasional escapee.

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*I'm not an entomologist, and much of what I write about BSF is an educated guess.


Sat Jul 05, 2014 1:35 pm
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Post Re: Velcro hook tape as a larvae containment device
I just watched several larvae crawl right over a 1/2" wide strip of velcro hook tape on my collection drawer and escape. I'm guessing that they gunked it up enough to fill the gaps between the hooks or something? ugh. sometimes if feels like there is NOTHING that will contain the determined buggers :(


Thu Jul 09, 2015 11:30 pm
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Post Re: Velcro hook tape as a larvae containment device
What about Neverwet?

http://www.okeanosgroup.com/blog/aquari ... ium-hobby/

If moisture cannot accumulate then they cannot climb right?


Fri Jul 10, 2015 1:15 am
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Joined: Mon Jun 15, 2015 9:35 pm
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Post Re: Velcro hook tape as a larvae containment device
I fed my BSF larvae some leftovers from a restaurant and left the Styrofoam on the side of the bid where they tend to crawl off. It seems as thought the larvae have a difficult time climbing the Styrofoam so an idea popped into my head. I am building a compost bin and instead of using Velcro I sprayed a small line of spray on insulation foam around the upper inside edge of the bin. I have a feeling this will work great. I should be finished with the bin and have my BSF in there in a few days. I will keep you posted how they do.


Sat Jul 11, 2015 3:32 am
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