Visitors periodically ask us to weigh in on whether or not they should use Dermestid beetles and larvae as cleaner crews in their Dubia roach colonies. It is tempting to give a “yes” or “no” answer based on our experience, but that might discount the experience (or potential experience) of others. What happens in one colony may not happen in another. In the end, each case is at least a little different, and every situation is unique.
That said, there are some general concepts that may apply across the board, or nearly so. While location and environment, for example, are circumstantial, other things are universal. The fact that we are dealing with Dubia roach colonies is one example.
Instead of a simple yes or no answer, we provide anecdotal and other information about how insects work and have worked as cleaner crews in our colonies. We’ll report to you the good, the bad, and the ugly and allow you to decide for yourself whether to use Dermestid beetles or other cleaner crews in your Dubia colony, given your unique circumstances.
Our decision to add cleaner crews
Our decision to add Dermestes to our Dubia colonies was an easy one. In short, their benefits outweigh their costs. They are highly effective, they are the cheapest form of insurance against mold and bacteria-related problems we know, and they are easy to maintain. We could almost just drop them in our colonies and forget about them. As we discuss in our post about Dubia roach die-off, bacterial overgrowth is dangerous and something you want to avoid. It can cause grave harm to a colony, and cleaner crews may help you avoid it.
So for us, the answer is “yes”.
Since writing this article, we discovered that combination cleaner crews consisting of Dermestid beetles and lesser mealworms are more effective than either species alone. We like the two together and think they are worth considering for your situation. We discuss this in more detail below.
Unwanted bacterial growth is among the biggest potential problems with the dark, warm, moist environment Dubia roaches need for growth and reproduction. When combined with poor air circulation and the foods bacteria love to eat — like food particles, roach feces, and dead roaches — conditions inside a colony can go south in a hurry.
Unfortunately, this can have grave consequences. Die-offs are common among large captive tropical roach colonies, and Dubia roaches appear more susceptible than most.
Cleanliness is a related issue. Roach bins require regular cleaning, and the more humid the environment, the more frequent cleanings must be. Neglecting cleaning for too long can lead to an accumulation of frass and food particles. This material build-up contributes to mold, bacterial, and fungal growth, which can cause colony stress. Colony stress is a generalized condition that can lead to problems like slow growth, reduced breeding, and even death. These are all things you want to avoid.
In addition to being a danger to the roaches, moisture build-up and the fungi and bacteria that tend to follow can cause foul smells. This may or not be an issue for you depending on how many colonies you have and where you keep them. Smell is probably going to be an issue for most people. Dubia roaches don’t tend to smell bad, and we consider this one of their many benefits. However, this benefit is lost when bacteria colonize a Dubia colony.
Dermestid beetles and larvae, with help from another cleaner species, have reduced and prevented these problems in our colonies.
Dermestid beetles and larvae eat dead roaches. In sufficiently large numbers, they can greatly reduce the amount of decaying organic matter in an enclosure. Because this is the fuel bacteria need to grow, bacterial growth can be reduced along with its ability to gain a foothold in a colony. In theory, a reduction in bacteria equals a reduction in the risk of harm, and this concept has proven true in our experience.
Reducing the number of decaying roaches also cuts down on moisture build-up. Moisture can become trapped in dead roaches — especially ones buried deep in frass. Colonies with high relative humidity are the most vulnerable to this danger. Once it starts, this process tends to snowball, and the bin must be cleaned to avoid further (and potentially more serious) issues.
Unfortunately, moisture build-up often occurs beneath the surface, out of sight for the most part. It is not always apparent, and you may not notice it until it is far advanced. As a general rule, reducing moisture lowers the risk bacteria will harm a colony. In our experience, the best ways to reduce moisture are (a) reduce humidity, (b) clean regularly, and (c) add cleaner crews.
What does one have to do for all these benefits? Not much, actually. Dermestidae are relatively carefree insects. They don’t require much maintenance and are easier to keep than tropical roaches. Managing a Dubia colony requires more skill than a population of Dermestidae cleaners. And notably, managing cleaner insects is a lot less work than dealing with a roach colony that has gone bad from neglect. It can be a lot less expensive too. Again — a die-off is a worst-case scenario, but we’ve experienced them. They’re no fun, and you should work hard to avoid them.
Are cleaner crews worth it?
While Dermestid cleaners are relatively easy to keep, they’re not completely hands-off. They require at least some maintenance effort. Most people can probably get away with just adding a batch of beetles and larvae to their colony and checking in occasionally to see how they’re doing. However, we recommend taking a little more care with them than that. Learning how to tend to them takes a little time up-front, but once you’ve done that, the maintenance itself is easy. They may, for example, need supplemental food if the roach colony is too small to support them.
The upside of cleaner crews
For us, the main Dermestid benefits are less required maintenance, better colony health (less risk), and better smell. It’s easy for us to let maintenance slip with so many colonies. Adding cleaner crews to them reduced the number of health-related incidents like moisture accumulation and die-offs. Less frequent cleaning means less stress for the roaches and less disturbance. And frass serves an important biological function — especially for nymphs. We don’t want to disturb our roaches any more than we have to, and we don’t want to remove any more frass than is necessary.
Without cleaner crews, we find that we have to be more strict with our enclosure maintenance to avoid health problems in our colonies. Cleaner crews allow us to manage more colonies with less effort. And they give us more margin for error. For example, one sign of colony trouble is the smell of ammonia. When that occurs, we usually find unprocessed dead roaches and moisture build-up in the frass. At this point, the bin needs to be cleaned, which is a lot of work. As mentioned, it also disturbs the roaches and deprives them of the frass they need for good health.
But we avoided this almost entirely with the inclusion of Dermestidae cleaners. Further, we had no troublesome bacteria overgrowth after adding a combination of Dermestidae and lesser mealworms.
We think, as a rule, lesser mealworms complement Dermestidae by eating plant matter and feces, whereas Dermestid beetles and larvae eat only animal matter. Lesser mealworms will eat dead roaches too, but they don’t prefer it. Outdoors, Lesser mealworms live in compost piles and animal feces, which seems like a natural fit for a roach bin with frass as a substrate. They do seem to be thriving and very happy there.
All things equal, in our experience, the combination of the two insects is more effective than either alone. We have had good results in colonies with either species alone, but the best scavenging and cleaning results from using them together.
The downside of cleaner crews
Maintaining a colony of Dermestid beetles and larvae in roach enclosures requires periodic checks to see how they’re doing. These checks involve looking inside the bin to determine their numbers and activity. Getting a sense of how they’re doing helps alert us to any issues early before they can develop into bigger problems. Occasionally, we decide to reduce their numbers in one colony or several, which is a relatively straightforward process.
That’s it for the downside. Not bad.
It is important to note that Dermestidae has been reported to be pests capable of eating through floors and walls (external link). We have not seen this. Perhaps we don’t have the right climate here. Whatever the case, be aware that while we have not had any issues, the potential for problems may exist. You should be sure they will not cause problems for you before you buy them. The same is true for lesser mealworms. They may be a pest in some circumstances. For example, poultry producers consider them pests because they get into discarded chicken manure.
Dermestid beetles and lesser mealworms are native to the United States and are found throughout the country.
As for any negative impacts of cleaner crews on roach breeding, we have not experienced any. Cleaner crews are another thing to consider when managing a colony, as previously mentioned, but they are relatively carefree and hearty creatures. Once established, they tend to reduce the number of things we need to think about daily rather than increase them.
While a possibility exists that they could grow out of control, this seems unlikely. It has never happened to us, and we have not heard of it happening to others. Dermestid and Lesser mealworm growth is limited by food. Excess food will not be available unless there is a massive roach die-off or care and cleaning are neglected. If either of these is true, a colony has bigger and more urgent problems than a growing cleaner crew population.
And again, the numbers of either species (or both) can be reduced when desired.
This brings us full circle back to “the upside”. We found that as a general rule if the Dermestids and lesser mealworms are doing OK in a colony, the roaches are OK too. As such, cleaner crews may serve as a trouble notification system. A sort of “canary in a coal mine”, if you will. They can alert to potential problems with the roaches. So in addition to reducing the likelihood of trouble, they also warn of it. This gives us a certain peace of mind.
Read more: The complete guide to caring for Dubia roach cleaner crews »
We have seen and experienced compelling reasons to use Dermestid beetles and larvae with lesser mealworms and beetles as cleaner crews. From a purely functional roach-raising perspective, their benefits substantially outweigh their costs. In combination with lesser mealworm cleaners, Dermestid beetles and larvae may afford a larger margin of safety for a colony than one without them. We work with roaches on a large scale, and cleaner crews have made our lives easier. They have helped us grow and maintain healthier colonies with less work, and they have given us peace of mind.
Have a question?
If you have a question, please feel free to ask! You can use the comment form below.
Hello, in your opinion can I use dermestide in a cricket colony too?
While this is not something we’ve tried, it’s possible. Cricket colony dynamics are different from roach colonies. For example, they require frequent cleaning and rotation, so using dermestids may not be practical or necessary. However, it might be an interesting experiment.
Mike C says
If I get an excessive amounts of beetles and meal worms can I feed them to my dragons? Can I put them into my dragons cage to clean out that cage? What’s the difference or similarities of the Meal worm and lesser meal worm?
Mealworms and lesser mealworms are different but related species, the primary difference between them being their size. You can find lots of information about both species online. For example: here for lesser mealworm info (external link) and here for mealworm info (external link).
If they will eat them, it’s probably OK to feed lesser mealworms to your bearded dragons. We haven’t heard of any problems with this, but if you experiment, take it slow and maybe do some research. It seems likely that mealworms are only more common than lesser mealworms as reptile food because of their size. Lesser mealworms are tiny. Mealworms are probably a good fit for a wider range of animals.
Be careful with the beetles though. Some reptiles won’t eat mealworm beetles, and it’s always a good idea to use a feeding dish rather than letting tiny worms and beetles roam free.
How many dermestids and lesser mealworms do I need for a tote of 500 Dubias between 1 and 3 inches?
You can go with either 1 or 2 Cleaner Crew kits. One should be fine, and two will get you to equilibrium faster. It’s up to you which you choose.
You mention at some point to put the clean frass back into the container. But how do you clean it if it’s technically poop and body parts?
Frass is indeed roach poop and discarded exoskeletons, as you mention. In and of itself, and within reason, frass is good for roaches. For example, it aids gut colonization of specialized beneficial bacteria in newborn nymphs.
But too much frass can cause problems in a captive roach colony. It can become too deep over time, for example. It can also become contaminated with things that are not beneficial for the roaches, like uneaten food.
“Cleaning frass” means reducing its volume and removing unwanted contaminants. After cleaning, it will still be bacteria-laden roach poop, but this is a good thing for Dubia roaches. You just don’t want too much of this good thing. “Clean” for roaches and clean for people don’t necessarily mean the same things.
Omega E. says
There are literally thousands of them living under the Deadfall and in the soil of my natural tank for my bearded dragon, is there going to be a problem, other than if they were to start laying eggs of course (the dragon) seeing as these critters are flesh eaters…
If one of our Dubia colonies were to become overrun by cleaner crews, we would lower their numbers.
Cleaner crews reduce uneaten food, dead roaches, and other waste that can otherwise build up and cause problems in a roach colony. You only need enough of them to accomplish this. At some point, their benefits diminish. We wouldn’t want cleaner crews crowding out our roaches, and you probably don’t want them crowding out your animal either.
While we use cleaner crews in our Dubia colonies, their benefits don’t necessarily translate to a cage housing a single reptile. The two situations are different, and their functionality in one circumstance does not necessarily transfer to another.
If you find a benefit to using cleaner crews in a reptile cage, that’s great, but we don’t recommend letting them grow out of control. If they’re becoming a nuisance, it may be time for a cleaning.
Karen V. says
I managed to get Dermestid beetles in my bearded Dragon tank that has coconut fibers. Will they harm him?
Seems unlikely. Dermestid beetles only eat dead flesh, and their population can only expand if they have enough food to support larger numbers. If there is no dead flesh in the tank for them to eat and grow, they cannot survive.
In Dubia colonies, Dermestid beetles largely ignore live roaches. They just don’t seem to have any interest in living things at all.
I never added any cleaner insects in my colony, but when I was checking the colony one day I notice this black looking small worm and researched it what I think it’s a larvae beetle, how would it get in my tub when I’ve never added any?
As a matter of course, captive roach colonies may tend to attract other insects. Some may be wanted, others unwanted. Some may be harmless, others harmful. Mites come to mind in the unwanted/harmful category. The best thing to do is identify the worm, decide on a course of action, and work from there. A feature of carnivorous insects like Dermestid beetles and larvae is that they naturally migrate toward dead animal matter, so it sounds like they (or perhaps some other insect) found your Dubia colony.
How many beetles/lesser mealworms should I add to a colony of 1/2 to 1 inch dubias? There are 1000 dubias in the colony.
One or two cleaner crew kits will do just fine. Whether you choose one or two kits to start depends on how fast you want the cleaner crews to establish in the Dubia colony. Two is faster, one a little slower, but both will get you to where you want to be in the end.
The Longfellows says
How many buffalo beetle should I put in with a 1000 dubia to make a difference?
You can start with one or two of our cleaner crew kits. Buffalo beetles reproduce relatively fast, so one or two should work fine.
I have a dubia roach colony along with Dermestid beetles. Today I noticed I have what looks like little baby worms on the bottom of my tote. What is this? Are the worms bad for my roaches?
Based on your description, those worms are the larvae phase of Dermestid beetles. If you have other cleaner crew species like lesser mealworm (beetles), the worms you see could be the larval phase of that insect. These are two of the most common cleaner species, and all things equal, neither are likely to harm your roaches.
Alex P. says
I’ve read that Dermestid beetles can fly. Do you have many escapees when you open the lids to your dubia colony containers?
Dermestid beetles can fly when the temperature is high enough, but they aren’t very aggressive in this way. Because of how we set up our system, this isn’t something we see very often.
Emma V. says
Love the article! Very informative and comprehensive! Do Dermestid beetles and lesser mealworms require any kind of substrate at the bottom of the roach bin?
No additional substrate needed.
Josh S says
I am assuming that the cleaners cannot clime the walls of a typical tote? If a bearded dragon were to accidentally eat one would it harm them? Thanks
Correct – neither cleaner species can climb smooth plastic typical with many totes. If it’s rough, they may be able to. And no, neither insect poses any general harm if ingested by a bearded dragon or other animal. Lesser mealworms are related to regular mealworms, and animals tend to avoid the beetles because they secrete a substance they don’t like.
How much frass does a colony need and why do they need it? I am starting a discoid colony as dubia are illegal in my state. I have been picking the nymphs out and putting them in a separate bin. Should I not do this?
It’s probably best to keep a little frass in with the roaches, especially the nymphs. For Dubia nymphs, frass provides nitrogen and bacteria for digestive system colonization, which is important. This is probably the case for other roach species as well, though how important may vary species to species. The bottom line is that frass is probably not critical for captive roach survival, but it may tend to improve their health and colony viability.
I raise mealworms; would a clean up crew be effective in reducing frass and the dead?
It seems unlikely on the surface. Cleaner crews include lesser mealworms and Dermestid beetles/larvae. The lesser mealworms would probably compete with the regular mealworms for resources, and there may not be enough dead mealworms to sustain a Dermestid population.
However, you could give it a try if you wanted to experiment.
Great info here!!! I have just started a Dubia “colony” and was wondering if you suggest introducing cleaner crews immediately or waiting. If I should wait, then How long?
Rather than making up a rule, I’d base the decision of when to add cleaner crews on the needs and conditions of the colony and your unique situation. Generally, it’s going to depend on colony size and conditions in and around the bin.
Excess waste build-up in a captive roach colony is the primary issue. Signs of it include moist frass, clumping, foul smells including ammonia, and mold or mildew. There may also be fly larvae and flies in and around the bin. Cleaner crews can help mitigate these problems. If you have any of them now, it is time to consider adding cleaner crews.
However, I’m not aware of any benefit to cleaners beyond their potential to remove excess waste. Remember that frass is beneficial for roaches. If it wasn’t, you could just clean out the bin once or twice a week and forget the cleaner crews. So ideally you want to leave some frass in the colony. But frass also makes conditions that could harm the colony more likely. The trick is finding a balance between sterility and excess that works for both you and your colony.
The bottom line is that if you have a small colony that produces little frass and there’s no problem with waste build-up, you can probably hold off on cleaner crews if you want. But you could also add them if you want. If you add them early you have to consider sustaining them, which is covered in the article. On the other hand, cleaner crews may help if your colony has any of the issues above. Of course, there’s a lot of ground in-between, so it’s a judgment call that takes your unique situation into account.
I have super worm beetles can I use them for cleaners in my Dubias I have a colony tank and and my feeder tank ?
Interesting question. We lean toward no for a few reasons.
First, superworms and beetles may stress the roaches. They’re large, and they bite when searching for food. If this is the case, it’s enough to avoid them entirely.
Dubia roaches are very vulnerable when they molt, and even other roaches in the colony will take bites out of molting roaches. If superworms were to do this, it could devastate the colony.
Second, superworms burrow like lesser mealworms. Because of their size, they could conceivably destroy paper-based harborage pretty fast.
These are just theories — we haven’t tested superworms as cleaner crews in our roach bins, but we would have some concerns.
thank you . I hadn’t thought about them biting my roaches I wouldn’t want them bitten or my babys bitten or ate ‘ or stressed out’
Michael J. says
I have had the occasional superworm get into a dubia colony, not a good experience for mine. Once they matured into beetles, the dubia avoided being anywhere within several inches of them, to the point of one side of the box being so crowded that the roaches covered their entire surface area of egg carton, and the side with just two beetles being nearly absent of dubia. My guess is the noxious odor of the beetles, as the larva were ignored. I would expect a similar yet weaker reaction to the regular mealworm beetles, since they smell almost as bad, although not as potent.
Interesting observation about superworms. We have not seen the same thing with lesser mealworms. However, it is possible they could pose some degree of annoyance to Dubia roaches.
There are always trade-offs in using cleaner crews. We use regular cleaning to keep the lesser mealworm population level in balance.
You can do the same with the superworms, or you can eliminate them entirely if you wish. The removal process is fairly straightforward.
I’m soon getting a dubia roach colony, and from what I’ve read, the “substrate” you keep them in is frass (as they produce it over time). But your lesser meal worm and dermestid beetles seem to be shipped in some earth or dirt. Do I just throw them in the dubia bin with earth and all when I get them, or do I have to pick them out and put them in?
We often ship dermestid and other cleaner crews in their own frass. That is what resembles dirt. The insects are small so their frass is small too. You can separate the insects from their frass if you like, but it may contain some eggs, so the best (and easiest) thing to do is dump the entire contents of the cleaner crew container into your Dubia colony.
Nancy J. says
I think I added too many cleaner beetles (in this case tenebrio obscura) to my young dubia colony. I bought less than 150 roaches, all sizes but no adults. Then I read about adding cleaner beetles and added 100 of those.
The problem, as I see it, is the beetle larva is now eating all the dubia food. Maybe I should have waited until the roach colony was mature and reproducing before adding beetles? I recently started feeding my roaches Repashy bug burgers and was so impressed because it was disappearing overnite! Haha, I realized it is the beetle larva eating it! I guess there isn’t enough dead or discarded roach skins to feed them. The floor of my bin, and the food dishes are a writhing mass of larva and they are climbing the egg crates! How can that not be stressing out the roaches?
The dubia should have babies any time now. How do I really reduce the beetle larva (very tiny to 1/2″) without reducing the frass that the roach nymphs will need? (I was ready to get rid of the beetles/larva until I read the above information. Now I don’t know what to do…)
We came up with a simple and effective way to reduce the number of cleaner insects in Dubia colonies.
First, find a small container around 1 to 3 inches tall. The sides should be smooth enough that the cleaner insects can’t climb them. We use plastic, but glass would probably work just as well. The walls need to be high enough so the insects can’t climb out and wide enough to wedge between harborage so that it’s touching multiple places where the cleaner insects crawl. You could also make a “bridge” over the top of the container.
Then, add a small amount of food and set the container in the enclosure. Beetles and larvae will fall in. Check it often because roaches may also become trapped. Ideally, you can find a shallow container that traps all the cleaners, but some roaches can climb out.
That’s it. Empty and repeat. This method is surprisingly effective at reducing the number of cleaner crews in a colony, and it works fast!
I read about someone freezing and keeping frazz for later use. If you get insects cold it will slow them down and make it easier to sort them. Would probably kill the roaches but could apply it to the beetles and larva sorting.
What is “frass”??
Frass is the material that accumulates over time in Dubia roach and other insect colonies. It’s made up of discarded shell, feces, uneaten food, and other debris.
I have one question: I am using the beetles as cleaner crews. I always have trouble during cleaning – I end up throwing a lot away. I was just wondering if you have any tips for separating larva and beetles from frass. Thank you all your information. It is useful and greatly appreciated!
A bucket with small holes may work, but this may not be necessary. At least some frass is usually a good idea.
When we clean Dubia roach bins, we remove all the frass and then add some back after we sift and clean it. This frass contains cleaner crew beetles, larvae, and eggs, and their population recovers quickly. Not having enough cleaner crews has never been a problem. They tend to be rather prolific.