A die-off in a colony of captive Dubia roaches is when there is (a) a rise in death rate that is usually well beyond what is normal for the colony, and (b) when this increase has an external cause. By definition, and for the purpose of this discussion, both must be true. Without substantially increased deaths and a cause, the colony is just doing what colonies do. There is no need to take action in this case.
However, in the case of a die-off, there is much to do and you must do it without delay. Die-offs are very serious. They can decimate a colony’s population and even destroy it entirely. Colony collapse is a very real possibility. You must take immediate steps to investigate the situation, identify any problems, and resolve them.
Fortunately, a die-off can often be stopped and the remaining roaches returned to health if appropriate action is taken. In a worst-case scenario though, and without intervention, a sick colony may collapse and all its roaches may die.
That’s worst-cast though. It’s not inevitable, of course. We wrote this guide to help. With correct knowledge and proper strategy, intervention can be successful.
Table of Contents
- Die-off basics
- How to approach the problem
- Symptoms of a die off
- Identifying causes
- Mitigating damage
- Final recommendations
Given enough time, every roach-keeper experiences a die-off. It’s like that saying about motorcycle riders: There are two kinds – those who have gone down, and those who will. This applies nicely to breeding tropical roaches. While Dubia are considered hearty roaches, they require a specific and often narrow range of environmental conditions to thrive and reproduce. These include heat, elevated humidity, and darkness. This means that to be successful, you must expose your roaches to conditions that may also make them sick, and it’s only a matter of time before they do.
For this reason, we consider occasional bouts of poor colony health to be par for the course. One day a colony looks healthy by all appearances. It bustles with energy: The roaches are eating well and behaving normally. Then seemingly out of the blue the “energy” declines and a number of sick and dead roaches appear. One day everything is fine and the next thing you know the colony is not well. When this happens, you do what you can and hope for the best. As these things go, the cause often remains a mystery. The roaches often recover before any real damage is done and without any residual effect. However, if the sickness and death within the colony signal a die-off, the next hours and days are likely to bring more. As will the day after that if nothing is done to stop it.
Die-offs can be scary. They may reduce a colony’s population by 5%, 10%, 25% or more in just hours or days. And depending on the cause and proximity, other colonies can be affected too. Or infected, if you like. If you’ve discovered a possible problem in one of your Dubia colonies and you want to fix it, first know that: (a) Dubia roach die offs are fairly common, and (b) you might able to stop it from progressing and get your roaches healthy again even if you don’t yet know the cause. You might return them to health even if you never find the cause. Sick colonies are not necessarily doomed.
How to approach the problem
With a hopeful eye toward finding solutions, our approach here is to intervene quickly and mitigate damage. We do this without too much concern for establishing cause along the way. This means that for the purposes of this guide, our desire to find causality takes a backseat to halting the damage. We do not focus on testing hypotheses in this guide. We are problem-solving. Our concern is with the colony and preventing its untimely demise. This is Dubia roach triage, and we are working to save the most seriously affected. Roaches are dying and the situation may be critical. Fast action is required. Intervention often takes some time to work so there is no time to waste. The priority is fixing the problem even if it comes at the expense of finding the cause.
So consider up-front that you may learn what caused the die-off, but you may not. You can experiment by changing just one thing and seeing if the situation improves, but this increases your risk of losing the colony or losing more than you would had you taken more action. How you proceed is up to you. Just be aware that when there is a choice between resolution and finding cause, our advice going forward will lean heavily toward resolution.
It’s a shotgun approach, but it may save your colony. This means you may never know what the problem was once the colony begins to recover, or you may only have a general sense of it. You saw some problems, you fixed them, the roaches got better, and something you did seems to have worked. On one hand, you have your colony back. On the other hand the problem may be more likely to recur. This is the trade-off. In the short-run, your colony lives to breed another day.
Symptoms of a die off
In broad terms, an unusually high number of dead roaches is the main sign of a die-off. Obviously the number and to some degree even the rate of death that will cause you concern varies by colony size, but somewhere around 2% and up per day should raise an eyebrow. For example, it may not mean anything if you have 10 roaches and two die, but if you have 100 and 20 die, or you have 1,000 and 200 die, this is a very different situation. The latter two cases strongly suggest a problem. The first does not. Two roaches out of ten could easily randomly die.
You may be able to determine if the colony is experiencing a die-off by comparing its current death rate to what is normal. This only works of course if you’re in-tune with colony norms. If you aren’t, the next best thing may be to wait and see what happens in a few hours or perhaps a day. If the death rate declines to something reasonable, the colony is probably safe and whatever happened was either nothing or it resolved on its own. If your roaches keep dying, something is probably going on that needs attention. And of course if the death rate climbs you likely have your answer.
So with any luck there’s nothing to see. The colony isn’t sick and everything returns to normal within a day. But if you decide further investigation is needed, keep reading to learn what to look for.
In most cases, dead roaches are not the first sign of a die-off. Sick roaches are. Fortunately, sick roaches are easy to spot when there’s a larger problem with the colony. They’re easy to identify generally, but they stand out much more en masse. If you find more dead roaches than usual, look for sick roaches.
As an aside, it may be a good idea to develop a habit of scanning your colony for sick roaches. If you don’t already, make it part of your routine in the future. It doesn’t take much (or even any) effort once you’re in the habit, and it may help avoid a problem altogether. Ridding a colony of sickly roaches quickly can head off some problems before they have a chance to develop. You can quarantine sick roaches, or you might even feed them off to your animals before you feed off the healthy ones. Of course this depends on your animal as well as what may be making your roaches sick. It’s something to consider.
Begin by examining the roaches in their bin. Keep in mind that you’re looking for clues about the source and magnitude of a potentially serious problem. Consider that if there is an issue, it will fall somewhere on a continuum between “chronic” and “acute”. The reason for doing this should be clear: You want to figure out what the extent of the problem is, but what you really want to do is to identify the problem itself. Or at least what the problem is likely to be. This will help you work toward a solution. To that end, deciding if the die-off looks like something acute versus chronic will help you narrow down potential causes and find possible solutions.
It may be helpful at this point to know that roaches tend to die quickly after exposure to a lethal dose of toxic chemicals or physical injury. Of course, this isn’t always the case, but it’s a good general rule. So you want to rule this out quickly, or determine if it’s a likelihood or even a possibility. This is because poisoning is among the most serious findings, and the most urgent. You will have to take action quickly if that’s what you’ve got. A “slow” die-off means chemical exposure is less likely, and if by chance it is an exposure, it may be less serious.
Look for signs of sickness among the roaches as you search the enclosure. Signs of some kind of exposure are lethargy, lack of coordination, and lack of response to direct stimulation. Before death, Dubia roaches with an acute toxic chemical exposure may slow down or stop crawling. They may also lose coordination, roll over onto their backs, and either remain still or move their legs and head rapidly. When these sick roaches are righted, they often fail to straighten their body. They will immediately roll onto their back again. Death usually comes within a day or two for these roaches, though they may appear to linger in this altered-state longer.
Interestingly, it’s possible that these listless and lethargic roaches are already dead. Cockroaches have a central nervous system that does not require their head be attached to their body. They are famously able to move and even appear normal for a time after their head is removed. Not that we advocate this, of course. The point is that the presence of motor response does not necessarily mean that a roach is “alive”. At least not in the way we think of being alive. Keep this in mind.
Chronic chemical exposure (or an acute exposure to a sub-lethal dose) is probably more common than exposure to a lethal dose of poison. Also keep this in mind as you search the colony. If there was a massive poisoning, the roaches would probably already be dead, or they will be soon. If this is the case, there’s nothing you can do to help the ones that have been exposed. In this case, the hope would be that you can save the roaches that are not yet exposed.
The good news is that your roaches are still alive, but unfortunately that means the cause is harder to find. It’s much easier to deal with a situation where you feed your roaches a batch of bad grapes, for example, and they suddenly start dropping dead than it is to deal with a scenario where something you feed them slowly poisons them over time. Or maybe your neighbor fumigated and the chemicals reached your colony. Maybe some grain you fed them a month ago was contaminated with a bacteria toxic to Dubia roaches and that bacteria has grown and spread over time. There are a lot of possibilities to consider here, but they do fall into categories that can be addressed.
Here are more symptoms to look for as you search:
Sick roaches may lose the ability to grip with their feet and legs. Healthy Dubia roaches can walk upside-down on your hand. They can move quickly and easily. Sick roaches tend to be slow and may slide off the palm of the hand.
Sick roaches struggle to walk. Their hind legs may spread out wide beyond their body. They may shuffle or waddle as their feet slip and their movements become more uncoordinated over time.
At some point, a sick roach may have difficulty staying upright. It may may walk some, but then fall to one side then onto its back, where it may not right itself.
Then, the roach may have a hard time staying alive.
These processes and the transition from bad health to worse can take hours or days. How long probably depends on the root cause. When you see dead roaches, look around for live roaches with these problems. Pick up an egg crate in the bin and see what happens. As mentioned, sick roaches lose their grip, so if a lot of them fall to the ground, check for signs of illness. Look at the ones on the ground. They may have trouble righting themselves. If they do right themselves, they may not try to scamper away or they may not get far if they try.
Consider that in every colony there will be a number of dead and dying roaches. This is expected and normal. What isn’t normal is a large number of dead or dying roaches relative to the size of the colony.
Sick roaches tend to linger at the bottom of their enclosure. They may be sluggish or listless. If you touch them they may not run away. They might move a bit and stop or they might try to scamper away and fail because their feet don’t grip the ground. Or, they may not move much at all. The body of a sick roach is often soft and “squishy” to the touch. This is compared to how a Dubia roach body usually feels, which could be described as “firm”. So a sick roach may have a soft body and be relatively unresponsive to touch.
Interestingly, the more unhealthy they become, the softer their bodies feel. If you find sluggish roaches with soft bodies in your search, consider them to be sick and separate them. (Quarantining is described below)
During a die-off, separating sick and potentially sick roaches from the rest may result in avoiding further decline. It can stop the progress of whatever is killing the roaches. This is very easy to do. Grab a small container – one that’s just big enough to house a small number of roaches – add some food, water, and harborage, and add slow or sluggish roaches to it as you go. If you’re breeding these roaches, it may be a good idea to set up two emergency recovery containers. The first week you fill up the first, then set it aside and fill up the second. If the roaches in bin 1 are OK and look normal and healthy after a week you can add them back to the colony.
If you’re lucky, the die off is caused by old age. Female Dubia breeders in particular are under a lot of physical stress. The strain of captivity, which commonly include overcrowded living conditions, incorrect feed, poor nutrition, and nonstop procreation, can all take a toll. If you bought your breeders from the same seller at one time there is a good chance the roaches are all about the same age. Because they may be the same age and experienced the same conditions throughout their lives, they may tend to die at about the same time. Of course, if you wake up one morning and half your colony is gone, chances are it’s something else, but if you noticed more and more roaches seem to be dying lately and the number is approaching the number of roaches you bought when you started your colony, old age is a possibility. The main point here beyond pointing out a potential cause of the die-off is to get you thinking about all the possibilities. This includes the Dubia roach life cycle.
Unfortunately, the symptoms of death from old age are similar to those of low-dose toxin exposure. It is difficult and sometimes impossible to tell if old age is causing the die off by looking at symptoms alone. The conclusion that a die-off is caused by “old age” is one you may reach after other causes are ruled out. This conclusion is usually circumstantial rather than something you find with direct evidence.
Having said that, it may be useful to count the number of dead males and females and compare that to past Dubia roach purchases. Did you buy a large group of females at some point? After you factor in the colony’s female:male ratio, are most of the fatalities female? If you have 50 dead females and 4 dead males and a ratio of 5:1, there is a good chance whatever is going on is either affecting females more than males, which is unlikely, so perhaps that points to age. If you happened to have bought 100 female breeders four months ago from an unknown supplier, and you think there is a chance they sold you a batch of old roaches, you may have your answer.
Because most things that can go wrong with Dubia roaches lead to similar symptoms, we’re left with circumstantial analysis in the search for cause and solution. Think about what it could be, compare that to the symptoms you find and the circumstances of your colony, act, then see what happens. During this process, it is important to keep an open mind. Remember that you don’t have to draw conclusions right now. When you feel a temptation to rule something out reflexively, be cautious. The following list of die-off causes can get you started thinking about what may be happening in your colony, and what to do to fix it.
Mold and fungus
Dubia roaches naturally live on the forest floor, and this is a mold and fungus-rich environment. However, molds and other fungi have been known to wipe out captive colonies, so the lesson seems to be something like this: Keeping Dubia roach colonies in dark, wet, hot boxes is different than living free in the rain forest. And, as we know, funky things can happen in a dark, wet, hot box. So be careful with colonies you keep in these conditions, which by definition – assuming you’re breeding your Dubia – will be most of them.
As mentioned above, Dubia roach enclosures are a prime environment for bacteria. The good news is that most bacteria are harmless. Some are even beneficial. For example, Dubia roaches require that a certain bacteria colonize their gut to help them digest food. And, certain micro-organisms may provide them with key macronutrients when they are lacking in the diet. But there are bad bacteria too, and if one of these bad bacteria makes its way into your colony, it can take hold and make it sick. It could even wipe it out. The key variable here is the environment, and of course, what you put in it. You can control both things within reason. Dubia roaches need humidity to breed. They also need heat, but their enclosure doesn’t have to resemble a sauna.
The simple act of feeding Dubia roaches introduces all sorts of foreign matter from any number of places into the environment that was just described above as prime for the spread of bacteria. Have you ever been to a farm or seen the back of a delivery truck? These are not clean places. Bacteria are everywhere. One spot of dirt on one piece of vegetation can harbor millions of germs…all waiting to find a new home in a dark, wet, hot place just like your Dubia roach colony. Again, most bacteria are not bad, and some are even good. Some though, are bad, and bad ones can cause die-offs.
Unless you’ve gone fully organic, you never know what chemicals are in the food you feed your roaches. As we’ve said before: Pesticides are designed to kill insects and Dubia roaches are insects. Chemicals can persist on and in foods, and chemical contamination of one sort or another should be a prime suspect in any Dubia roach die off. So what do you feed your roaches, and what did you feed them lately?
Here’s an anecdote that turned into an “anecdon’t”: We added regular, non-organic quinoa to our roach chow mix one time a while back. Two days later 1/4 of our roaches were dead or dying. However, no other species of roach was affected. We have no idea why. Needless to say, we don’t give our roaches non-organic quinoa any more. Not that we planned to make a habit of it – we just happened to get a deal on it. The crazy thing is that we bought the quinoa at a local upscale grocery store. So always keep an open mind, and also consider keeping a log or at least a mental note of new foods you add to the colony and perhaps new methods of preparing or providing it. Logs can be helpful for retracing steps to solve a problem.
Water can contain chemicals, and water quality varies depending on where you live or where you buy it. Water also harbors bacteria and other living contaminants. Understand that if the die-off is mold or bacteria-related, water will be involved one way or another. Contamination either came from water or was enabled by it because neither mold nor bacteria can grow in the numbers required to cause problems in completely arid environments. Remember: dark, moist, and wet. One way to rule in water issues is to note if it gets smelly or discolored between changes. If so, this is a sign to investigate further.
Many people house Dubia roach colonies in plastic bins. This doesn’t seem to be a problem generally, but keep in mind that plastic contains chemicals that no one should think were designed to be roach friendly. In fact, if a container maker found that their storage bins were deadly to roaches, they might even consider that a good thing. With a die-off in a colony kept in a plastic bin, consider it at least possible that the bin is a problem. Plastic is generally made of petroleum products and may contain endocrine disrupting chemicals like Bisphenol A (BPA) (external link) and probably others. It’s certainly not implausible that something in the material is causing health issues among your roaches. We haven’t run into this in our colonies, but we’ve looked into it. There are so many different plastic bins on the market and it’s hard to imagine none of them contain chemicals that cause roaches harm. If your roaches are dying and you bought a new plastic bin a few days or weeks ago, you should investigate this possible connection.
Most harborage in homemade roach colonies is made from paper products. Paper products are often loaded with chemicals (external link). There is a common belief that roaches can survive eating things like paper, wallpaper paste, and cardboard. This happens to be mostly true, though you shouldn’t try breeding your roaches on a diet of wallpaper paste. Survival is quite often very different from “health”, and this is certainly true among Dubia roaches. It’s usually pest roach species that are found eating walls, not Dubia roaches.
While we consider paper and cardboard generally safe for use with Dubia roaches, you should be at least a little cautious, especially with brands or products you haven’t used in your colony before. It’s difficult and perhaps impossible to know what glues and dyes and binders and bleaches different manufacturers use. Or maybe a manufacturer decides to change a chemical or a process, and a product that had been harmless to roaches now makes them sick. It’s possible. It’s also possible that by virtue of simple bad luck you end up with cardboard that contains something that made your roaches sick. It could happen. In fact we’ve known it to happen, or at least strongly suspected.
Too much or too little heat. That is the question. Dubia roaches can handle temperatures down into the 60’s and even 50’s (Fahrenheit). They won’t breed there but they won’t die either. They just kind of maintain forever at low temperatures, lingering and not growing. But they do survive. Alternatively, while B. dubia can handle higher temperatures than other species (pdf) (external link), anything above about 90ºF seems to start causing problems. Then there is the connection between heat, humidity, and all of the associated problems working against the captive breeding of tropical roaches.
Think about what products, if any, could have come in contact with your roaches. Keep in mind that it doesn’t take much and that chemicals often persist in the home long after they’re applied. Have you used flea spray or powder in your home recently? If not, is there any chance there may be some residue inside your vacuum cleaner? Did you empty your vacuum cleaner bag recently? Do you use bleach or other household cleaning chemicals on items that come in contact with your roaches? Did you fumigate your home either professionally or with a “bug bomb” in the last year? How about your neighbors? Have you ever sprayed a roach killing spray in your home? You would be amazed how quickly old residue from a bug spray kills roaches. We have no idea how long that stuff lingers, but it is at least in the range of “months” and perhaps longer.
Give this some thought. Solutions are covered by cleaning under “General Actions” below. If you haven’t already, now is a good time to remove all potentially harmful substances from where you keep your colony. It’s also a good time to resolve to not use chemical poisons near your roaches. Don’t use them at all in your home if you can avoid it. To take a random example, flea powder in carpet can be tracked everywhere in your home, and it will kill roaches long after you forgot that you used it. It also kills roaches in very small amounts that you cannot detect.
Mitigating damage: what to do
So after all that…or maybe you skipped here to get to the important stuff…now you have to figure out what to do. As we said in the beginning, you don’t have to know what is causing the die off to take steps to stop it. In fact, there doesn’t even have to be a confirmed die-off to take these steps at all. The better idea you have about what may be happening the better you’re able to focus your efforts on effective action, but you can still act if you have no clue what’s happening. There are a finite number of things that could be causing problems in the colony, and they tend to fall into categories that can be addressed by taking certain actions. And some things should be done by everyone regardless of situation. Other things may be situational.
The following “actions” are split into two areas: “general” and “targeted”. General actions are a good idea no matter what turns out to be happening in your colony, and whatever the cause of the die-off (if there is one).
Do these things…
- Wash your hands before and after handling anything within a colony, and always between colonies.
- Clean everything with non-toxic soap and water. We recommend “green soaps” that are free of harmful chemicals. Let everything dry and keep everything clean. Remove all non-essential items from the storage area. Move all food and other perishable items to a refrigerator or freezer.
- Remove dead roaches. Dead roaches should be removed as often as possible and properly discarded.
- Quarantine sick roaches. Separate the sick from the healthy and move sick colonies away from healthy ones. The goal is to isolate the sick roaches as much as possible.
- Use two levels of quarantine. After the complete separation of sick and well, remove the roaches you think may be healthy from the sick colony and put them in a new bin. Locate the bin either in the same location as the sick colony or a new location away from both the sick and healthy colonies. Don’t under any circumstances remove roaches you think might be OK from the sick colony and put them into one of your healthy colonies. From the moment you realize there is a problem, keep the sick away from the well until the situation is resolved.
- Set up a “recovery” container for sick roaches if it makes more sense to remove them from the colony. If they pull through and are doing well in a week or two and the colony survived the die off, you can add them back in. If they die you can dispose of them, and in the meantime they will not contribute to the further decline of the larger colony from which they were separated
- Track the dead. Take a daily count to chart die-off progress and the actions you take to combat it.
You can take some of the following actions or you can take them all. What you choose depends on what you know and understand about the die off, and whether or not what you just did resolved it.
Mold and fungus
If you suspect mold or fungus is at the root of the die off, try to remove the source. This means starting with a clean enclosure, new harborage, and new food and water. Depending on the severity of the problem you may consider a new enclosure with new amenities as above, but using disposable harborage you can throw out and replace with ease. This is because you will provide another newly cleaned enclosure with new amenities 24 hours later and every 24 hours until the die off stops.
If this sounds extreme, you probably aren’t losing enough roaches for it to be worthwhile. If you consider this option, know that it can help if the cause is bacterial or mold-related, but it may take a few days to start working, and in the end it may not be enough to halt the deaths. It can work if it reduces the burden on the roaches to the point where they can overcome its effects, but then you’ll have to be very mindful of the circumstances that could lead to a recurrence and take steps to reduce the likelihood without any feedback about whether or not what you’ve done had any effect.
Sources of mold and other fungi can be fruits, vegetables, water, moist food, moist frass, moist harborage, and dead roaches or cleaner crews. Dubia are scavengers and they naturally live in moldy, bacteria-rich environments, but mold can kill a captive colony. So it must be that certain molds are bad for Dubia roaches while others are not. Or it could be that there was too much of one they normally tolerate. Until the die off is under control, feed only dry food and check it daily to make sure it remains dry. Don’t feed anything wet until after the die off is resolved. You might even consider not feeding anything at all. Dubia roaches can go long periods without food so they may do OK or even well with nothing at all. The balance is that they’re sick and may fight off illness better with nutritional support. And, it may depend on the situation and what’s causing the die-off.
Make sure the enclosure’s ventilation is adequate. You may have to guess at this because there’s no standard by which ventilation is measured, other than “adequate”. This means enough air circulating to prevent moisture build-up from humidity leading to mold, bacteria, fungi, etc. One clue that enclosure ventilation is inadequate is a consistently high humidity along with a musty or foul smell. If you suspect bad things are growing in your colony and causing problems, the solution is to increase ventilation and possibly even reduce the humidity. You can also reduce humidity by changing or adjusting your watering method, but be cautious because it’s possible to have the right humidity and still have inadequate ventilation. The basic rule is that air quality in a Dubia colony is a balance between humidity and circulation. Ventilation obviously plays an important role in that balance.
If you suspect that your Dubia colony’s problems are caused by bacteria, clean everything and start fresh. Avoid moisture as much as possible until the die off is resolved. Only then start again with fruits and vegetables. When you do start again, start slowly. You may not need to go slow if you find and resolve the ultimate cause of the die off, but if you don’t, go slow and look for problems that may signal its return.
If you think the problem relates to the food you feed your roaches, the solution is to remove ALL food except for one preferably dry ingredient you believe to be safe, wait for the die off to resolve, then slowly start adding ingredients back into the colony’s diet while observing the results. The one “safe” ingredient should be something like organic oats or wheat – something you know and trust or at least something that is likely to be safe. Depending on circumstances, you may want to start with something new that you don’t already feed your roaches. After all, something made them sick, and it would be a shame to switch to a basic diet and choose the one food that is making them sick as their “safe base”.
The general implication here is that something your roaches are eating is causing the deaths. This is not uncommon. Pesticides are designed to kill insects and they do that job well. It only takes a small amount, chemicals often persist on and around our foods, and effects may be cumulative. You could have a colony of seemingly healthy roaches breeding and doing great…while they slowly accumulate more and more of a pesticide until one day it gets to the point where the roaches start getting sick and dying.
When you replace your regular food with a single trusted ingredient, don’t worry about it not providing a balanced diet. Dubia roaches thrive when nutrients are plentiful but they can survive on almost no food or poor quality food for quite a while. And assuming you started with otherwise healthy roaches, they aren’t going to lose that health in a week or two. If you bought them from us they have been eating healthy, nutrient-dense food from the day they were born. With cockroaches, the benefits of a healthy diet are cumulative (external link). Worry about stopping your Dubia roaches from dying and then figuring out the cause rather than providing the best possible nutrition, at least for now.
If the cause of the problem is pesticide, think back on whether your roaches have been eating less lately. Also try to figure out if production is low or if they’ve been listless for a while. These measures of general health are likely to decline along with general colony health. In other words, when a Dubia colony is sick production will be lower than normal. In the case where only one of multiple colonies is affected, these measures will fall in just the affected colony. In these cases it can be easy to see. However, if the source of the exposure is common to all the colonies, as in the case of food, then a side-by-side comparison probably won’t reveal anything worthwhile. All the roaches will all be affected if they are all exposed.
A general note on toxic exposure: Roaches that accumulate low-dose toxins over time may show signs of distress and illness well before they start dying. They may exhibit any of the behavior changes already mentioned. These changes may occur slowly over time, or rapidly.
Consider excess protein as a potential cause for a die-off. We know this goes against popular opinion. However, our experience diverges from popular opinion and we have to go with what we see – especially when it is consistent with science. We believe that too much protein is bad for Dubia roaches for a variety of reasons. There is an amount of protein that will cause roach health to decline. However, opinions differ on how much protein is “too much”. It seems that about 25% is maximum for good health. Roaches can probably do with much less. If you feed your Dubia roaches substantially more protein than 25%, consider that this may be causing your die-off. Also consider reducing the amount of protein you feed your roaches regardless of what the die-off cause ultimately is. You can read more about this if you like in an article about why too much protein may not be healthy for Dubia roaches.
If you try dietary elimination, be aware that it may not work right away. And if it doesn’t work right away it may still be the correct response. Roaches that become sick over time won’t get better overnight. They may even die no matter what you do. Depending on how toxic their food has been, the best you might hope for is to stop further toxicity or prevent new roaches from exposure. Remember to remove all dead roaches from the enclosure as quickly as possible. Live roaches often eat the dead ones, creating a new exposure, and you want to prevent this.
Dealing with a water issue is closely related to mold, bacteria, and food. Not only are they closely related, but the same concepts apply. Remove existing watering supplies completely and consider finding a new method and a new source of water in case the die-off has something to do with the supplies you use or the method itself. Maybe a sponge supplying water attracts some kind of mold that is poisoning the roaches. Maybe it contains chemical toxins. Or maybe your water district added a different chemical recently or your water supply was switched. If there are hidden issue here they may resolve if you eliminate them by trying something new.
If you suspect the enclosure is the cause and you aren’t using a glass aquarium or other glass cage, try a new enclosure. This is tricky because you have no way of knowing exactly what chemicals are in plastic storage bins. And since they break down over time, you can’t exactly get away with the idea that what’s worked for a while should always work. Now, if you have five colonies and all are in the same kind or brand of bin that you bought at the same time, and the roaches are only dying in one of them, chances are slim that the bin is the problem. On the other hand, if you bought a new plastic bin three days ago two days after you started using it your roaches started dying, that might be the most logical place to look for a cure.
There are also some questions you can ask yourself regarding bin issues: In the enclosure you currently use for the sick colony, did you use glue inside the bin or on anything you put inside the bin? Hot glue seems to be safe, but “superglue” may not be. Did you glue any other materials together that could be reacting in the heat and humidity? If so, consider replacing them with an alternative. Did you do anything unusual recently with the items in the bin?
Harborage can cause problems if it’s laced with harmful chemicals. In these cases the culprits are usually paper and cardboard. Even the egg crates commonly used in Dubia roach colonies may break down over time or contain some additive that either alone or in combination with something else you’re using is causing the die off. Are you using new paper or cardboard?
When in doubt, or if you desperately need to stop the die off, try removing all harborage. You can add something for the roaches to climb on if you like, but make it something clean, new, and preferably not the same type or brand you just removed. What you’re doing now involves eliminating all possible causes – sort of like an “elimination diet”. You want to start of with as few things as possible, and you want the things you start with to be clean and not cause problems – or at least reasonably assumed to be. Then after you establish a healthy baseline and the die off resolves you can start adding things back. Paper and cardboard are generally safe, but they have been known to cause problems.
Heat, or the lack of it, may contribute to a die off. Constant temperatures well below or sometimes even a little too high can cause major problems for Dubia roaches. They generally like temperatures between 80ºF and 85ºF, and maybe approaching 90ºF. We know this because they tend to move to lower temperatures when exposed to higher heat and higher temperatures when the temperature is lower. Whenever possible, listen to your roaches. They can show you what they need.
Take a quick look at your roaches if you’ve checked the temperatures and it seems OK. Do they mostly hang out on the cool side of the enclosure away from the heat source? Do they huddle in a large mass either near or on top of the heat, seemingly not wanting to venture away for things like food and water? Let these behaviors guide you in heating your enclosure. If your roaches run away from heat as fast as they can when the temperature pushes 95ºF, that is more significant and authoritative than the person who told you they breed best at that temperature. Or, it could be that the temperature is uneven and rising higher in some places than others. Whatever the case, don’t push things your roaches respond poorly too – no matter where you got the information. You may want to figure out what’s happening, but the ultimate experts are the roaches themselves.
Regarding Dubia health: high heat is more often a problem than low heat. They need high heat to thrive and breed, but that comes with the problems mentioned previously. Heat, moisture, humidity, darkness…this is where funky stuff grows. Low heat is not ideal for reproduction, but until it gets very low, Dubia roaches will not die. And low heat generally means low humidity and low(er) potential for bacterial growth. So, high heat is more associated with die-offs than low heat, in our experience.
With high heat, check things like moisture collection, circulation, unusual or unpleasant smells, food acceptance, water depletion, etc. This has already been addressed in detail above.
As you know or can imagine, chemicalscan cause roaches of all species to die. Chemical contamination is a particularly insidious problem because when roaches die, the chemicals they got on them or into them become part of the environment. This will happen in your colony too unless you remove their bodies quickly. Insecticides probably don’t change after ingestion. In fact, they are made to be persistent in the environment. After all, they wouldn’t do much good if they evaporated in five minutes or were carried away with ease. So manufacturers make them so they stick around, and they do this in a number of ways. Roaches that nibble on a dead bin-mate, as roaches do, may themselves die from the toxin. Then the next roach to come along that takes a bit will die too. This can be repeated again and again, particularly in small spaces…such as your Dubia colony.
The recommendation is to clean the sick colony thoroughly and stock the enclosure with new harborage, food and water, etc. Remove the dead bodies as soon as you find them. Ideally this will be several times a day. If that’s not possible, aim for once in the morning and once at night. 24 hours is too long to wait. By then any cleaning insects you may have in your enclosure will have started eating the body, and other roaches may have started to do the same. The deaths will continue until this cycle is broken. There are diminishing returns of course and it won’t perpetuate forever, but the best, fastest way to break the cycle is to quickly remove chemically contaminated dead roaches.
After the cleanup, focus on avoidance. Don’t use any household cleaners like bleach or Ajax or germ killer or whatever on your bin or any items you put inside the bin. You can run bowls and such through the dishwasher because the water is so hot and cleaning so thorough that residue is removed, but the same cannot be said for hand-washing. If you use soap to wash your enclosure, consider an “ecologically friendly” one with no harmful chemicals. Soap residue stays on the things you wash. It may not harm people, but insects are a different matter. Many cleaning products contain bactericides and other chemicals designed to kill organisms that are not people, and you should not assume those chemicals are safe for insects. In fact, you should probably assume that they are not.
As you work through a die off, be vigilant and open to all possibilities. This includes being wrong. Don’t be afraid to act preemptively – and when necessary, drastically – to save your Dubia colony. There are a lot of reasons colonies and roaches get sick. Some are more easily remedied than others, but almost all of them leave room for substantial or partial salvage of the colony and reversal back to good health. When you act fast, good things are possible. You may lose some roaches, but some is better than all.
Consider keeping a log of changes you make and what you observe generally, and rethink the situation often. Read as much as you can about others who have had this experience. Be open to doing some work…even if what you want decide you should do erases all the work you just did. If you try something or read something that clicks and something suddenly makes sense, go with that. If figuring out your die-off was easy or the causes obvious, you wouldn’t be here. Why these things happen are often a mystery. You may get an answer, but you may not. Hopefully you will try some new things, learn something about your colony or Dubia roaches generally, and after the crisis has passed you will be a better roach-keeper for having experienced it.
Of course, when your roaches are dying, you just want it fixed ASAP. Suggesting that you read about the problem and think about possible causes may seem kind of insulting in the heat of the moment. So do everything you can and try to think of everything. Rule out the most serious causes first. Separate sick roaches from the healthy. Use new, fresh enclosures, food, and everything else for the “healthy” roaches that you don’t quarantine and keep an eye on the status of the ones you do. Do everything you can and give your roaches what they need to recover. As you do these things, know that not all hope is lost. Not yet anyway. Roaches are hearty creatures with a remarkable knack for survival.