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Can I use mothballs in my hives?

No. Mothballs, whether made out of naphthalene or para-dichlorobenzene, are insecticides and insect repellents that have no place in a hive containing live bees. Several people have asked if putting the crystals in a bee-proof space—such as a net bag or wire cage—would keep the bees safe from contact. Again the answer is no because it is the inhaled gas that is poisonous.

Both of these chemicals, commonly used to treat clothes moths, work by subliming in a closed environment. Sublimation simply means the material goes straight from the solid state to the gaseous state. The gas, in an enclosed space, builds up to toxic levels that will kill moths and other insects. At lower concentrations, it acts to repel rather than kill the organisms, due to the unpleasant odor.

Since you neither want to kill nor repel your honey bees, you do not want these products in any hive that currently contains bees. Crystals of para-dichlorobenzene are often used in stored bee boxes to keep wax combs free of moths during the winter months, which is fine, but the equipment must be thoroughly aired before being used with live bees. The advantage of para-dichlorobenzene over naphthalene is that the odor will dissipate quickly. On the other hand, equipment treated with naphthalene mothballs may smell nasty for months (or years) to come.

Also, honey meant for human consumption must never be exposed to these products. Not only will it smell bad, but deleterious health effects are known or suspected for each. Both are listed as known carcinogens by the State of California, and para-dichlorobenzene is a neurotoxin. Naphthalene-containing products have been banned by the EU since 2008.

So use para-dichlorobenzene (such as Para-Moth) only for storage of boxes and frames.The best way to control wax moths in active hives is to keep colonies strong and healthy, and to provide no more space than the colony can effectively patrol. Colonies that have other problems, such as beetle infestations or Varroa mites, are more likely to fall victim to a wax moth infestation. Colonies with too many boxes for the size of the colony also easily become victims.

Rusty
HoneyBeeSuite

Comments

Mary Powers
Reply

Makes me wonder how many people have done, or will do, that and *don’t* ask before hand. Who knows how many bees you just saved, Rusty?!

Steve Craig
Reply

Para-Moth is sold in bee supplier catalogs and they really don’t give the chemical name. They just say “not for use in California or Hawaii”. After a google search I found out that Para-Moth is para-dichlorobenzene. From your post above it is a big “NO” for this chemical. I guess if they included the dichlorobenzene name it might scare off some customers. I am sure the label may say that you can not use it in the hive. I am worried that too many people just do not read labels. Besides many of us older people all remember clothes closets with the smell of moth balls. Now they are carcinogens at least in some states. It is no wonder why bees are having such a hard life with “humans” taking care of them. Maybe that is why they try to escape, swarm, and return to the wild, away from the chemical using person trying to “keep them healthy” I am only a hobby beekeeper so maybe I am wrong and it is common practice to use Para-Moth in commercial operations. I read your big “NO” as meaning never. I put my frames in the freezer to protect them. The big commercial guys maybe can’t afford a big freezer.

Rusty
Reply

Steve,

The big No is for people who want to use these chemicals in hives that contain live bees. Para-Moth is fine for its intended use, which is for long-term storage of drawn comb and frames, and is certainly better than using naphthalene. As I said in the post, as long as the equipment is thoroughly aired after use (I believe they recommend at least 24 hours) it is fine because para-dichlorobenzene dissipates much faster than naphthalene. However, neither product should be used in the presence of bees.

aaldahri
Reply

Thank you, Rusty.

Bil
Reply

I am amazed that anyone, even more so a beekeeper, would consider putting mothballs in a hive. In the past I have used formic acid but for the last 2 seasons I have gone without treatments.

Joanna
Reply

OOO! This just gave me an idea! I’m still struggling with that dratted hornet nest right over my bee hive. They were bagged with a waterproof mattress pad and two plastic garbage bags for a week and when I removed the outer most layer there were many dead dropping but still some flyers—probably because it didn’t get hot enough to kill eggs/larvae. I’m re-bagging tonight (after researching life cycle better) but thinking about taping some Para-Moth into the top of the bag. Crazy? Sounds like it shouldn’t be persistent enough to bother the bees but may sublimate enough to expedite the hornet termination? I am a bit at wit’s end as I can’t work the bee hive comfortably with the crazy ladies right there.

Rusty
Reply

Joanna,

Wow, I can’t believe you’re still at those hornets. Persistent, aren’t they?

Herts Honey Bee Supplies UK
Reply

Granny’s moth-balls are the last thing you want near your bees. First it is illegal to be found in food for human consumption and certainly would contaminate wax and honey. It has also been found to be cancer promoting.

Definitely a no…no.

Store unused super-comb in a cool and dry sheltered place outside. Make the stack bee-proof using a mesh floor screen to stop mice and robbing bees and roof on top… No waxmoth problems!

William
Reply

Hello Rusty:

I cleaned up some old supers given to me that had some wax moth damage. After cleaning I stacked and stored them in a building with moth crystals (dichlorobenzene). If I air these supers out for several days will they be ok to put on the hives? What do you suggest?

Rusty
Reply

William,

I think they will be fine, but make sure to air them out thoroughly in a well-ventilated place. It may take more than a few days to get the smell out.

Tammy
Reply

A co-worker told me he put his new wax foundations in a black bag with a moth ball in a ziplock so waxmoths don’t invade. I heard this also on Youtube. It has Naphthalene in it….and before they used it, they aired it out for a month. I did this last month and found out that it is a BAD thing. Did I ruin my wax foundation that hasn’t been combed out yet?

Rusty
Reply

Tammy,

Just make sure they are completely and absolutely aired out before you use them. From what I’ve read, the wax does absorb napthalene, but airing reduces it by quite a bit. Be sure you smell nothing.

arthur mcculloch
Reply

I used napthalene to store my extracted honey combs over last winter (southern hemisphere). I aired two boxes for two weeks prior to putting them on my two hobby hives last weekend. One hive is now dead. The other seems ok. I will not use it again. A disaster. I have about four more boxes in storage and am thinking that I will dispose of the combs and start over with fresh foundation.

Rusty
Reply

Arthur,

Good to know. Thank you.

Jimm
Reply

I have honey bees, non aggressive, that are underneath a trim board under my eves. How do I get them to leave without killing them? There are two air holes, I can open up, if someone can help me to get them out of there. Thank you for any help.

Rusty
Reply

Jimm,

I don’t have an answer for you. If you call a local beekeeping club, someone there might know someone in your area who does removals.

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