Dubia Roach Die-Off

A die-off in a colony of captive Dubia roaches is when there is (a) a rise in the death rate that is usually well beyond 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 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, die-offs 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 the roaches may die.

That’s worst-case though. It’s not inevitable. With the 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
  • Sick roaches
  • Old age
• Identifying causes
  • mold & fungus
  • Bacteria
  • Food
  • Water
  • Enclosure
  • Harborage
  • Heat
  • Chemicals
• Mitigating damage
  • General actions
  • Targeted actions
    • Mold and fungus
    • Ventilation
    • Bacteria
    • Food
    • Pesticide
    • Protein
    • Water
    • Enclosure
    • Harborage
    • Heat
    • Chemicals
• Final recommendations

Given enough time, every roach keeper experiences a die-off. It’s like what they say about motorcycle riders: There are two kinds — those who have gone down and those who will. This old expression applies nicely to breeding tropical insects. While Dubia are considered hearty roaches, they require a specific and often narrow range of conditions to thrive and reproduce. These include high heat, humidity, and plenty of darkness.

Unfortunately, these necessary conditions also increase the odds that your roaches will become sick. In our experience, it’s only a matter of time before they do.

So we consider occasional bouts of poor colony health par for the course. One day a colony appears healthy. It bustles with energy. The roaches are eating well and behaving normally. Then seemingly out of the blue, the colony’s energy declines, and you start noticing sick or dead roaches. 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. If you’re lucky, the roaches will recover before the colony sustains significant damage, and there is no residual effect. However, if the sickness and death indicate a die-off, the next hours and days will likely bring more. As will the day after that if you do nothing to stop it.

Die-off basics

Die-offs can be scary. They may reduce a colony’s population by 5%, 10%, 25%, or more in 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 damages. We do this without too much concern for establishing the die-off’s cause along the way. For the purposes of this guide, finding causality takes a backseat to halting the damage. We won’t focus on testing hypotheses. We are problem-solving. Our concern is for the colony, and our goal is to prevent its untimely demise. We are performing Dubia roach triage. Roaches are dying, and the situation may be critical. Fast action is required. Intervention often takes time to work, so there is no time to waste. The priority is fixing the problem.

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 have had you taken more action. How you proceed is up to you. Just know that when there is a choice between solving the problem and finding the cause, we focus on solutions.

Ours is a shotgun approach, but it may save your colony. You may never learn what caused your colony’s die-off. But with our help, you will hopefully find some problems, fix them, and your roaches will recover. On one hand, you may get your colony back to health. On the other hand, the problem may be more likely to recur. The trade-off is that 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. A death rate of around 2% and up per day should raise an eyebrow. For example, if you have ten roaches, it may not mean anything if two die. But if you have 100 roaches and 20 die, or you have 1,000 and 200 die, these are very different situations. The latter two cases strongly suggest a problem. The first situation does not. Two roaches out of ten could die by chance. When 200 out of 1,000 die, that’s not random.

You may determine if the colony is experiencing a die-off by comparing its current death rate to normal. This comparison only works 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 a day. If the death rate declines to something reasonable, the colony is probably safe, and whatever happened didn’t indicate anything. Or maybe the problem cleared up 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 signs to look for.

Sick roaches

In most cases, dead roaches are not the first sign of a die-off. Sick roaches are. Fortunately, sick roaches are easy to spot. 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. It doesn’t take much effort once you’re in the habit, and the practice may help you avoid problems altogether. Quickly removing sickly roaches from a colony can head off some problems before they have a chance to develop. You can quarantine any sick roaches you find, or you might feed them to your animals before feeding off healthier ones. Of course, this depends on what kind of animals you have. It also depends on what might be making your roaches sick. It’s something to consider. If there’s any doubt, just quarantine them and observe them to see what happens.

Start your search for sick roaches by examining the 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.” You want to figure out the extent of any problem, but ideally, you want to identify the problem itself. Or at least what the problem is likely to be. This will help you as you work toward a solution. Deciding if the die-off looks acute versus chronic will help you narrow down potential causes and find possible solutions.

At this point, it may be helpful to know that roaches tend to die quickly after exposure to a lethal dose of toxic chemicals or physical injury. While not always the case, this is a good general rule. So you want to rule this out quickly or determine if it’s a possibility or a likelihood. Poisoning is among the most serious findings. If this is what you’ve got, you must take action quickly. A “slow” die-off means chemical exposure is less likely, and if by chance it is exposure, it may be a less serious one.

As you search the enclosure, look for signs of sickness among the roaches. Signs of exposure are lethargy, lack of coordination, and lack of response to direct stimulation. Before death, Dubia roaches with acute toxic chemical exposure may slow down or stop crawling. They may lose coordination, roll onto their backs, and either remain still or move their legs and head rapidly.

If you right one of these sick roaches, they often fail to straighten their body. They may 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 for longer.

Interestingly, it’s possible that these listless, lethargic roaches are already dead. The cockroach’s central nervous system does not require its head to be attached to its body. They are famously able to move and even appear normal without their head. 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 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 will be soon. If this is the case, there’s nothing you can do except try to save ones that are not yet exposed.

The good news is that there is hope if your roaches are alive. Unfortunately, this makes finding the cause of their bad health harder. It’s much easier to deal with situations where roaches eat a batch of tainted grapes, for example, and suddenly start dropping dead than when something you feed them slowly poisons them over time. Or maybe your neighbor fumigated, and the chemicals reached your colony. Or, maybe the grain you fed them a month ago was contaminated with a bacteria toxic to Dubia roaches, and that bacteria has grown and spread in the colony over time. There are a lot of possibilities to consider, but they do fall into categories you can address.

Here are more symptoms to look for as you search:

Sick roaches may lose the ability to grip with their legs and feet. 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 wide beyond their body. They may shuffle or waddle as their feet slip, and their movements become more and more uncoordinated over time.

At some point, a sick roach may have difficulty staying upright. It may walk for a bit but then fall to one side, then onto its back. It may not be able to right itself.

Then, the roach may have a hard time staying alive.

These processes and transitions from poor health to worse can take hours or days. How long probably depends on the root cause. When you see dead roaches, look for live ones with the previously mentioned problems. Pick up an egg crate in the bin and see what happens. As mentioned, sick roaches lose their grip, so if many roaches fall to the floor when you pick up their harborage, look for signs of illness. Inspect the ones on the ground. They may have trouble righting themselves. If they do right themselves, they may not try to scamper away or won’t get far if they do.

Consider that every normal and healthy colony has a number of dead and dying roaches. What isn’t normal is a large number of dead or dying roaches relative to the colony size.

Sick roaches tend to linger at the bottom of their enclosure. They are often sluggish and listless. If you touch them, they may not run away. They might move a little, then stop, or 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 often feels soft and “squishy” to the touch. Healthy Dubia roaches are firm and tend to be responsive to touch.

Interestingly, the more unhealthy they are, the softer their bodies become. If you find sluggish roaches with soft bodies in your search, consider them sick and separate them. You will find information about the process of quarantining below.

During a die-off, separating sick and potentially sick roaches from the rest may help avoid further decline. It may stop the progress of whatever is killing the roaches. Quarantining roaches is easy to do. Grab a small container (one big enough to house a small number of roaches), add some food, water, and harborage, then add any slow or sluggish roaches as you find them.

If you’re breeding these roaches it may be a good idea to set up two emergency recovery containers. The first week, fill up the first. Set it aside the next week and fill up the second. If the roaches in bin one are OK and look normal and healthy after a week, you can add them back to the colony.

Old age

If you’re lucky, the cause of the die-off is old age. Female Dubia breeders, for example, 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 the same time, there’s a good chance the roaches are all about the same age. Because they may be the same age and have the same stresses 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 notice more roaches dying lately, and the number of dead roaches is approaching the number you bought when you started your colony, then old age is a possibility. The main point here is to get you thinking about all potential causes of the die-off. One of these is the Dubia roach life cycle.

Unfortunately, symptoms of death from old age are similar to those of low-dose toxin exposure. It may be difficult or even impossible to tell if old age is causing the die-off by symptoms alone. The conclusion that old age caused the die-off is one you may reach after ruling out other causes. The evidence is usually circumstantial rather than something you identify directly.

That being said, you might 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 fatalities female? If you have 50 dead females and four dead males, and a ratio of 5:1, there’s a chance whatever is going on affects 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.

Identifying causes

Because most things that can go wrong with Dubia roaches lead to similar symptoms, we’re left with anecdotal 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, 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 the colony, and how 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.

Bacteria

As mentioned above, Dubia roach enclosures are prime environments for bacteria. The good news is that most bacteria are harmless. Some are even beneficial. For example, Dubia roaches require that certain bacteria colonize their gut to help them digest food. And certain micro-organisms may provide them with key macronutrients when 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.

Food

The simple act of feeding Dubia roaches introduces all sorts of foreign matter from any number of places into their environment — the one we just described as prime for spreading 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 like your Dubia roach colony. Again, most bacteria are not harmful, and some are even good. Some, however, 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 once 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 anymore. 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 them. Logs can be helpful for retracing steps to solve a problem.

Water

Water can contain chemicals, and water quality varies depending on where you live. Water also harbors bacteria and other living contaminants. Understand that if the die-off is mold or bacteria-related, water will be involved in 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 out water issues is to note if it gets smelly or discolored between changes. If so, this is a sign to investigate further.

Enclosure

Many people house Dubia roach colonies in plastic bins. Plastic doesn’t seem to be a problem generally, but keep in mind that plastic contains chemicals that no one should think are roach friendly. If a container maker found 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 the 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 brands of 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.

Harborage

Most harborage in homemade roach colonies is some form of paper product. These are often loaded with chemicals (external link). There is a common belief that roaches can survive by 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 different from “health.” This is certainly the case among Dubia roaches. Pest roach species are the ones usually 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 maybe 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 was harmless to roaches now makes them sick. It’s possible. It’s also possible that by simple bad luck, you end up with cardboard that contains something that made your roaches sick. It could happen.

Heat

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.

Chemicals

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 use. 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 chemicals near your roaches. Don’t use them at all in your home if you can avoid them. A random example: Flea powder in carpet can be tracked everywhere in your home, and it will kill roaches long after you applied 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 can 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 the 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).

General actions

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.

Targeted actions

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 resolves 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 it out and replace it 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.

Ventilation

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.

Bacteria

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.

Food

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 the 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.

Pesticide

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 several 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.

Excess protein

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 the 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.

Water

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 issues here, they may resolve if you eliminate them by trying something new.

Enclosure

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

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 off 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

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 temperature 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 to – 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.

Chemicals

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, water, etc. Remove the dead bodies as soon as you find them. Ideally, this will be done 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.

Final recommendations

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 are 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 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 is 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.

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