Dubia roach: Care, Breeding and Feeding

Blaptica dubia.

Version 1.0 ©Andrew Johnson.

Other names:
Guyana spotted roach, Orange spotted roach, and Argentine roach.

Blaptica dubia are a large species of cockroach. They are sexually dimorphic (the males and females look different). Their colour is quite variable. The wings of males can range from brown to black, the abdomen of the females can be from almost entirely black, to dark brown with orange edges to the segments.

Males reach just over 4cm (including their wings), while females can exceed 4.5cm. The females are much bulkier. Nymphs can be between 5mm and 35mm, and are grey/brown. They look a bit like giant woodlice!

Distribution: South America

A mature female dubia roach will produce an ootheca or about 20-35 eggs. This is soon retained and incubated in a special brood pouch. About a month later, the eggs hatch, and the female appears to give birth to small (5mm) white nymphs. Nymphs are the juvenile stages of insects which exhibit incomplete metamorphosis, which includes all other roaches, true bugs, grasshopper and crickets. The rigid chitinous shell of nymphs cannot grow or expand very much. Therefore, the nymphs have to periodically shed their skin. I’m not sure how many moults the nymphs go through before adulthood, probably about 7. A nymph will roughly double in weight after each moult. A newly moulted roach will be white in colour, and very soft. Adulthood is achieved in 4 to 5 months, which become sexually mature after a couple of weeks. Males spend much of their time displaying to females. Adult males will live for approximately 9 months, the females live could probably reach 18 months. The females have a clutch of young every 2 months, probably less often as they get older.

Blaptica dubia are easy to house. These are the basic conditions they require:
1. Heat. They like a temperature of 25oC to 30oC
2. Moisture. This can be entirely from their diet.
3. Humidity. This aids shedding and reduces dehydration. Unfortunately it encourages mites, mould and bacteria
4. Food, covered in detail later.
5. Something to hide in/on/under. Roaches feel secure in small dark spaces.

There are 2 general ways to house them:

Natural set up:
They can be set up in an environment which is similar to their wild conditions. This would be soil, leaf litter, and perhaps some branches to climb on. It should be misted daily, so the substrate is slightly moist, but not damp. As a set up, this looks great. The roaches can behave naturally. For use as a container to breed feeders though, it is not so good. The roaches are difficult to find, numbers are difficult to monitor, there is a higher risk of pest establishing (such as mites), in which case its more difficult to clean out. The moisture levels lead to rotting foods.

Dry set up:
A ‘dry’ set up is the easiest way to house dubias. A plastic tub or some sort of suitable container is used. Importantly, it has to have smooth edges. Young dubia can (slowly) climb up aquarium sealant. I do not use a substrate, as this makes ‘harvesting’ the roaches difficult. Cardboard egg crates fill the tub. The roaches will live on these. It is important to place the egg crates alternately so that there are gaps for the roaches to move around. Dried food is provided ad lib, jus scattered on the floor. Fresh fruit or veg is provided regularly, but not constantly. Water can be provided with a sponge or with in a gel form. Make sure the sponge doesn’t touch the cardboard, as it will soak up all the moisture and make the culture damp. Water is not essential if there is regular fruit and vegetables. Occasionally the culture can be misted with water, though the culture must not remain damp. I heat these tubs with a heat mat, placed under half of the tub. Generally a thermostat is not necessary, but may save you money during the warmer months when the heat mat doesn’t need to be on as often. If they are all clustered away from the heat mat, then the culture is probably too hot.

Roaches are scavengers, making the most of little. Wild dubia probably eat fallen fruit, leaf litter, roots, seeds, leaves. Pretty much anything they find. They eat what is available, and efficiently get the nutrients they need from it. This means that they don’t need a particularly specialised diet, one of the reasons roaches are easy to keep and breed.

Here’s a list of possible food items for dubia roaches. It is not a definitive list of what is best. I haven’t scientifically tested any diets. All I know is that it works, and produces a plentiful supply of roaches!

1. Breakfast cereals make a cheap and easy diet for roaches. It is high in carbohydrates, which the roaches seem to appreciate. Weetabix (and its cheap alternatives) are very conveniently shaped for feeding roaches, as it doesn’t spread all over the tub, which means little food is wasted when cleaning a culture. This can be provided ad lib, but it must be kept dry, otherwise an infestation of mites is inevitable.
2. Bran is a by product of milling. It is a great food, very cheap, but also very nutritious. This can be provided ad lib, but again, it must be kept dry.
3. Poultry feed (layers pellets) is mixture made up of a mixture of grain, soybean, added vitamins and minerals. It is intended as a completed diet for laying hens. It is readily accepted by roaches, is very cheap, and offers a wide range or vitamins and minerals. I use this frequently because I have a constant supply, as I keep a couple of laying hens. Keep it dry.
4. Whole grains, such as wheat. This makes a very convenient food. It has a very low cost, contains wide range of nutrients. Most importantly, it is less susceptible to mite infestations, even when damp. Actually, I sometimes purposefully keep them moist for a few days before feeding, so they germinate. Sprouted seed has long been used as a healthy food to condition aviary birds. The composition of the grain changes dramatically during germination, becoming very high in sugars, which the roaches love. Other sprouting seeds can be used too, such as sunflower seeds, or even sprouting beans.
5. Fruit. Roaches really like to eat fruit. I have no doubt that is makes up a big part of their diet in the wild. Apple and banana are very readily available fruits, which I often use. Most if not all fruits suitable for humans are suitable for roaches. Watch out for insecticides though, which tend not to affect humans, but will affect roaches. Organic fruit is much better for that reason. Try not to have fruit (or veg) available all the time, as this encourages pests such as mites and fruit flies.
6. Vegetables. Again, vegetables probably make up a large part of their natural diet, although the term ‘vegetable’ covers loads of different foods. I use lots of foods such as potatoes and carrots, with smaller amounts of cabbage (and other brassicas, and pretty much any other vegetables. Care has to be taken so that there of no pesticides. This is especially important with leafy veg, but organic if possible.
7. Leaf litter. Leaf litter is much more of a substrate than a food, but they do eat small amounts of it. I usually put a few leaves in each culture for this. I use oak, beech and apple, though most brown leaves are fine. Wash and dry the to avoid introducing any pests into cultures.
8. Leaves. Unlike humans, roaches are able to digest cellulose, using bacteria in their gut (just like most herbivorous animals). Leaves can be added to their diet, such as fresh apple leaves, beech leaves, and grass.
9. Processed pet foods. Many people use dried dog food, cat food, or fish food to feed roaches. These are high in protein. BeforeI thought that this was an unessercery expense, after trying it, the roaches prefer it, and it appears to benefit them. As with all dried foods, they must be kept dry.
10. Kitchen scraps. Roaches are well known for eating scraps of food from the kitchen. This is fine in small quantities, but don’t feed any rotten or spoiled foods, any uncooked meat or dairy.

There are a few other foods that I will be trying with roaches. This includes various whole foods such as sunflower hearts, peanuts, and a wider range of fruit and veg, this article will be updated.

In conclusion, dubia roaches will eat a wide range of food. Feeding roaches need not be expensive; most of the foods can be bought in a supermarket.

*Update: They eat the sunflower hearts, although with no apparent preference over the other dried foods. The peanuts have to be broken before they will eat them*

Frequently asked questions:

How many roaches should I get?

I get asked this a lot. There are several things to consider:
How many do you need? If you just have one leopard gecko or one bearded dragon, you can just have a small culture of 30-50 adults. If you have lots to feed, get as many as you can. For most people, roaches subsidise some of the live food costs, so get as many as possible…
How much space do you have? There’s no point buying more that you can house. You’ll also have to account for the growing nymphs. For example, a tub 60cm x 30cm, could easily house 300 to 400 adults, but only up to 100 adults with their young up to “large nymphs”. If you feed off the smaller sizes, more can be housed.
How many can you afford? Starting up a large group of dubia is expensive. Due to the number being bred now, prices have gone down a lot over the past few years. If you have the space for them, it would easily pay itself back within 6 months in terms of live food costs saved.

Will dubia infest my house?
Cockroaches are an infamous pest. This is particularly true for a handful or species. Blaptica dubia however, is not one of them. Dubia does not escape particularly easily, as it does not climb, and is not really fast. If they do get out, they are not able to breed in a typical house, as it is too cold and dry for them. If your house is warm, provides moisture and food, e.g. you live in a heated greenhouse!!! (like the roach’s tub) they will survive and breed. Even in the tropical conditions where they are found, they are rarely found in houses

Can roaches replace crickets?
I’m not sure that I like the idea of roaches ‘replacing’ crickets, it would be better to use both. But crickets are not an essential part of a lizards diet, and the availability of roaches provides a healthy, easy and quiet alternative.

Where can I buy my dubia?
Of course, you should buy them from me! If, for whatever reason (e.g. I don’t have them available, personal grudge etc) you don’t want to buy them from me, there’s quite a few people selling them. Some reptile keeping friends will happily give away small amounts to start off your culture. For larger amounts, aim to buy from a breeder. They are generally much more knowledgeable about their care, and you can ensure your roaches are ‘fresh’. They also should know where the roaches came from, their age and what they’ve been fed etc.

Do you sell adults?
I occasionally have young adults for sale, sold in tubs of 16 (8 pairs). Take care when buying adults. All to often, cheap adults are ex breeders, or at least older breeders, who are not nearly as productive as young adults. With experience you can judge the age of the roaches by how they look and feel. Other indications of an older group are a high proportion of females. For example, a group of mine which have been adults for 9 months, started from an even ratio, is now 80 females to 25 males. Mortality rates are much higher, over 10% per month; compared to young adults which I’ve found have a mortality rate of less than 1% per month.

Do you sell colonies?
A colony is a group of organisms of the same species living together. I guess this means all the tubs I sell are ‘colonies’. Roaches are very social animals, although they don’t form the amazing complex colonies of eusocial insects. Actually, that is not true. One group of cockroaches, over millions of years, has become one of the most successful insects on the planet. These are the termites. Back on topic, when people want a colony, they probably think of a group of mixed sized roaches. I currently don’t sell mixed size groups, but you can buy and mix different sizes, so you know exactly what you’re getting.

Do you sell a roach diet?
The various components of the diet I use are very cheap and easily obtainable, all the ingredients are much less than £2/kilo, meaning delivery costs would be at least 100% of the actual cost. It’s just not worth it.

Can dubia be mixed with other roaches?
Provided the other species are not aggressive, require similar conditions and will not hybridise (I think all the available species are too different from dubia for this), then there shouldn’t be a problem.

How do you sex the nymphs?
The larger nymphs are easy to sex. Look on their underside, at the last segment of their abdomen. With males, the segment is small and narrow. With females, the last segment is large, as wide as the abdomen. Males also have much larger wing buds.

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