Visitors have asked us to weigh in on whether or not they should use Dermestid beetles and larvae as cleaner crews in their Dubia colonies.
Because each case is different and the decision is an individual one based on unique needs, we decided to explain how Dermestidae cleaners work in our roach colonies and let readers decide for themselves.
For us, the decision to add Dermestes to our colonies was an easy one. Their benefits far outweigh their costs. Dermestid beetles and larvae are highly effective cleaners. They are the cheapest form of insurance against bacteria-related problems we know, and they’re very easy to maintain. We could almost just drop them in our roach bins and forget them. As we discuss in our article about Dubia roach die-off, bacterial overgrowth is dangerous and something you never want to have to deal with. It can cause grave harm to a roach colony, and cleaner crews help us avoid it.
So from our perspective, the answer is yes.
We currently use Dermestid beetles and lesser mealworms in our colonies. We found that they work better together than either one alone. We recommend using the two in combination if that works for your colony and situation. We discuss this in more detail below.
Unwanted bacterial growth is probably the biggest drawback of the dark, warm, and moist climate Dubia roaches need for growth and reproduction. Combined with poor air circulation and the foods bacteria love to eat – namely food particles, roach feces, and dead roaches – colony conditions can go south fast. This can have grave consequences. Die-offs are not uncommon among large captive tropical roach colonies.
A related issue in captive colonies is cleanliness. Roach bins require regular cleaning. The more humid the environment, the more regular the cleaning needs to be. Neglecting cleaning for too long can lead to the die-off problem mentioned above, but even if it never gets that far, there are still benefits to keeping a tidy enclosure. Reduction of risk is one benefit. Peace of mind is another.
In addition to being a danger to the roaches, moisture build-up along with the bacteria that accompany it can produce foul smells. This may or not be an issue depending on how many roach colonies you have and where they’re kept, but smell is an issue for many people. Dubia roaches don’t tend to smell bad, which is one of their many benefits, but bacterial and moisture, if allowed to accumulate, can change that.
Dermestid beetles and larvae, with help from another cleaner species, prevent these problems in our colonies.
In a roach colony, Dermestid beetles and their larvae eat dead roaches. When their numbers are sufficiently large, they can greatly reduce the amount of decaying organic matter in an enclosure. This is the fuel bacteria use to grow. Take away their food and you take away bacteria’s ability to gain a foothold in a colony.
Reducing the number of decaying roaches also cuts down on moisture build-up. Moisture can become trapped and bacteria can grow and spread if dead roaches are buried deep enough in frass. Colonies kept in high humidity are the most vulnerable in this regard. Once the process begins it tends to snowball, and at this point the bin must be cleaned. The problem is that moisture build-up occurs beneath the surface, out of sight. It’s not always apparent, and it may not be noticed until it’s far advanced. Reducing moisture cuts the chance a colony will be harmed by bacteria, and the best way to do that is (a) lower humidty, or (b) regular cleaning and/or (c) cleaner crews.
And what does one have to do for all these benefits? Not much, actually. Dermestidae is a relatively care-free insect. They don’t require much maintenance. They’re certainly easier to keep than tropical roaches. Anyone who can manage a Dubia colony can manage 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, accident, or other causes. It’s a lot less expensive too. Again – a die-off is a worst-case scenario, but we’ve experienced them. They’re no fun and should be avoided.
Are They Worth It?
So while Dermestid cleaners are relatively easy, they aren’t completely hands-off. They do require at least a little effort to maintain. Most people can probably get away with just adding a batch of beetles and larvae to their colony and checking in from time to time to see how they’re doing, but 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 that’s done the maintenance itself is easy. They may, for example, need supplemental food if the colony they’re added to can’t support them yet.
For us, the major benefits of using Dermestidae in our colonies are lower maintenance and risk, and better smell. It’s easy to let maintenance slip with so many colonies, and the addition of cleaners reduces our risk. They’re also good for our roaches because infrequent cleaning is good for them. Less disturbance equals lower colony stress, and frass accumulation 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 necessary. Dermestid beetles help us achieve both.
Without cleaner crews, we find that we have to stay on top of enclosure maintenance to avoid colony health problems. With them, we can manage more colonies with less effort. And there’s more margin for error. For example, the first sign of trouble in a colony is usually the smell of ammonia. When that happens, 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 with Dermestidae cleaners, we’ve avoided this entirely. We’ve had no serious bacterial overgrowth events since we started using a combination of Dermestidae and lesser mealworms. As a rule, lesser mealworms compliment Dermestidae by eating plant matter. Dermestid beetles and larvae eat only animal matter. All things equal, we recommend the combination of the two insects versus either alone. We’ve had good results with both alone in the past, but the best scavenging and cleaning is achieved by both together. At the time of this writing, we use combination cleaner crews in all of our roach colonies.
Maintaining Dermestidae in roach colonies requires that we periodically check to see how they’re doing. This involves looking inside to get a sense of their numbers and activity. It’s very easy because we work with our colonies frequently. Those who may leave their colonies alone for weeks at a time may need to start checking every five to seven days. Of course, most of the time they’re fine, but frequent checks help alert to issues early, before they turn into problems. The more frequent the checks, the better.
It’s important to note that Dermestidae have been reported to be pests capable of eating through floors and walls (external link), but we haven’t seen this. Perhaps we don’t have the right climate here. So be aware that while we haven’t had issues with them, the potential for problems may exist. You should be sure they won’t cause problems for you before you buy them.
This actually brings us full-circle back to “the upside” category. Our colonies are climate-controlled due to our location. We’ve found that a general rule of thumb is that if the Dermestids are doing OK, the roaches are OK too. The Dermestidae population serves as a sort of “canary in a coal mine”. In addition to reducing the likelihood of trouble, they also warn of trouble if that first line of defense fails. A decline in the Dermestid population can be a sign that something is happening in the colony, and that it should be inspected for other signs of trouble.
As for negatives, there aren’t many. They aren’t free so there’s some expense up front – though their cost is relatively small. They’re also another thing to think about in managing a colony. As previously mentioned though, they’re easy to manage once established and they reduce rather than increase the number of things a roach-keeper needs to think about when managing a colony. While it’s possible they could grow out of control, this is very unlikely. We’ve never seen it happen. Dermestid growth is limited by food, and excess food won’t be available unless there’s a massive roach die-off. If that happens there are bigger and more urgent problems in the colony than an increasing Dermestidae population.
There are compelling reasons for us to use Dermestid beetles and larvae as cleaner crews in our roach colonies. In the final analysis, their benefits far outweigh their costs, and they afford us a margin of error that is appreciated when working with roaches on a large scale. They’ve made our lives easier. They’ve given us healthier colonies for less work, and importantly, they’ve given us peace of mind.