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Post by dertodesking on May 8, 2012 12:29:38 GMT -8
Dear All, I'd be most grateful to hear others opinions on the relative merits and drawbacks of both freezing and PDB as methods of eliminating an infestation in an insect collection. I'm aware of the noxious nature of PDB, and the associated potential health risks, but wondered if one method had an advantage over another..? Thanks  Simon |
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Post by johnnyboy on May 8, 2012 23:48:37 GMT -8
Simon,
I have used both methods of pest control in my collection. PDB is an effective killer of mites and dermestid beetle larvae. I have found that freezing an infested drawer is also effective, if one remembers to give the drawer a second freeze a week after the first, to kill any hatched larvae from eggs that have survived the first freezing.
Having said that, I still use PDB balls in all my drawers. They were still available, until recently, as "Carpet beetle killer" One or two collectors I know argued that they smelt like naphthalene, despite the packet saying 98.8% PDB. Although I was 100% sure they were PDB I got a research chemist friend to run a spectroscopic analysis on them and, surprise surprise, they were 98.8% PDB.
PDB is, in truth, not particularly toxic, (it wasn't so long ago that it was widely used as a loo sanitiser virtually everywhere) is an effective pest destroyer and will, if used over time in a cabinet, "plate out" on the surfaces of drawers to form a semi-permanent protection against museum beetle etc.
The room I keep my insect collection in is well ventilated with no detectable smell of chemicals. I also keep a supply of naphthalene (reasonably effective deterent) and camphor balls.
Freezing is OK but hastle and wont guarentee a collection stays unmolested if you don't use a chemical back up, unless perhaps if you have very tight fitting gap-free cabinets.
Thus I would recommend PDB (if available) over freezing.
PS There are now several "moth killer" products that contain the relatively new transfluthrin (a volatile fast-acting pyrethroid insecticide). As it is volatile it will be effective in fumigating insect drawers, rather like the banned dichlorovos (vapona) was) They come as strips or in sachets and last 6 months. Relatively safe and (although I haven't tried them) probably quite effective in killing pests.
Johnny
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Post by wollastoni on May 9, 2012 7:41:10 GMT -8
If PDB isn't that dangerous, why would have it been banned ?
I think PDB is very efficient as you said ... and thus dangerous. It's not so easy to kill dermestid larvas and adults, so it must be toxic on long term exposition.
There are too many cancers among museum curators to say PDB or other banned products are "not so toxic".
Personally I have stopped using PDB and have no freezer. So I don't treat anymore my collection but my drawer are good quality and I check them regularly + they still smell PDB so I guess they are still a little bit protected.
Is Ethyl acetate dangerous ? My supplier told me he has replaced PDB by this... but it seems to me even more toxic.
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Post by johnnyboy on May 9, 2012 11:19:54 GMT -8
PDB is only banned in the EU. In fact, you can swallow quite a large amount of it without it causing long term harm.
Everything, including the average urban atmosphere, carries a finite risk of harming human health. I personally don't think the risk is very high, we live in an over-protective EU.
Johnny
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Post by marsdenda on May 9, 2012 12:53:19 GMT -8
Have you thought about using Vapona strips? This is another alternative. You can buy the resin inpregnated strips and cut them to in 1/2 inch squares and put in your drawers or if you have a case just put them in the bottom if your drawers are not well sealed.
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Post by saturniidave on May 9, 2012 18:19:22 GMT -8
Johnny, Tesco now sells a 'safe' moth killer called Zensect. It is not cheap (around £4 for 20) and is like orange mothballs. They come in individual sachets which you can pin in your boxes etc. and smell of lavender. A friend has tried them and says they are very effective. I have bought some but not tried them yet.
Dave
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Post by johnnyboy on May 9, 2012 23:26:37 GMT -8
Dave, I haven't tried it, I suspect it has the relatively new pyrithroid transfluthrin as the active ingredient. Robert Dyas also sell sachets and strips with it (also quite expensive) .
As I mentioned, in my earlier post earlier, transfluthrin does appear to be an effective insecticide as it is volatile, rather like dichlorovos (vapona) was, and will therefore effectively fumigate collections. Contact insecticides are pretty useless for our purposes.
I will certainly try it at some point, it's great that there is now an effective alternative to all the banned compounds.
Johnny
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rjb
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Post by rjb on May 10, 2012 9:16:16 GMT -8
Wollastoni:
I think you can take ethyl acetate as being very safe. It is found in most alcoholic beverages. If you remember your organic chemistry, whenever you mix alcohol and vinegar you get some ethyl acetate. Check out the MSDS. You can practically drink it straight- but I don't think it tastes so good. When I am catching tiny beetles I often lick my finger so I can tap the beetle and transfer the stuck beetle to ethyl acetate. Then if I am doing many of these quickly, I end up dabbing EA onto my tongue a lot. It is OK but not as good as Bordeaux.
The problem with EA is it has a similar evaporation rate to alcohol, much higher than P-dichlorobenzene. If you try to fumigate your cases with it, most will evaporate and be gone in a few hours.
Rick
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Deleted
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Post by Deleted on May 10, 2012 10:23:38 GMT -8
almost as important as what you use is how often you inspect. If I make a new specimen case I use PDB for the first 6 months and then napthalene thereafter, inspecting each case at least every 3 months, have had no infestations dong this for a long time, any infestation when left unchecked can have a devestating effect in a very short time as my local museum found out when they came crying to me, in short prevention is certainly better than cure.
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Post by dertodesking on May 10, 2012 13:02:10 GMT -8
Gents, Many thanks for the useful and informative posts I keep my drawers and storeboxes WELL stocked with both PDB and napthalene which, until now, has prevented any infestation. However, on checking a drawer of Cerambycidae recently I was shocked to see signs of dermestids (frass under a couple of specimens  ) Anyway, thanks to all of the posts I think I'll go with a combination of both freezing (twice) and then a good restock of PDB. Like you, Johnny, I'm a bit sceptical about just how dangerous PDB is...but accept that a chemical that kills things probably isn't too good for your health! Interestingly, the drawer in question is one of my more recent ones...perhaps the drawer itself wasn't impregnanted yet with PDB fumes. Thanks again everyone! Simon |
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leptraps
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Post by leptraps on May 12, 2012 18:37:04 GMT -8
Inhale a little Ethyl Acetate and them attemp to take a drag off a cigar or cigarette and someone will be cashing in on your life insurance.
Ethyl Acetate is extremely combustable. Never ever use it indoors, unless you want some one to cash in your life insurance.
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rjb
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Post by rjb on May 13, 2012 2:38:23 GMT -8
Well if you smoke aren't you basically suicidal anyway?
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Post by lucanidae25 on May 13, 2012 21:26:01 GMT -8
Has any one try to think outside the Box???
Has any one try making their own fly paper the stick it on the inside of the side of the drawer all the way around. That will stop any dermestids enter into the drawer.
Just use masking tape and stick it all the way around on the inside walls of the drawer and make up 1/2 cup golden syrup; 1 tablespoon of dark brown sugar; 1 tablespoon of table sugar then mix and paint on the masking tape but not too much otherwise it will drip down.
Provided the new materials are all freezed before putting into the drawers, then you shouldn't have any more problem with dermestids.
Try it!!!!!!!
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Post by dertodesking on May 16, 2012 11:50:19 GMT -8
Has any one try to think outside the Box??? Has any one try making their own fly paper the stick it on the inside of the side of the drawer all the way around. That will stop any dermestids enter into the drawer. Just use masking tape and stick it all the way around on the inside walls of the drawer and make up 1/2 cup golden syrup; 1 tablespoon of dark brown sugar; 1 tablespoon of table sugar then mix and paint on the masking tape but not too much otherwise it will drip down. Provided the new materials are all freezed before putting into the drawers, then you shouldn't have any more problem with dermestids. Try it!!!!!!! Seriously?  You're recommending painting a sugaring mix onto the inside of the drawer??? Simon |
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Deleted
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Post by Deleted on May 16, 2012 14:25:52 GMT -8
I tried freezing and PDB. I didn't apprciate the condensation that formed after taking out the drawer from the freezer and I surely did not like inhaling fumes of PDB.
So, as you might have guessed, I'm once again suggesting Cedar Oil on cork pads as a deterent. Each 4 or so years, I put a square cm piece of Vapona in each drawer for a half year as a killing agent in case the Cedar Oil fails....which (btw) it has not. Sometimes I also treat individual specimens with an acetone dip or heat, but that is only for few instances.
Just my thoughts.
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