Dubia = Cannibals?

[unkempt1]

The title says it all. I don't mean well-fed and hydrated roaches, I mean just in general. Will the older ones eat the nymphs? I feed my roaches at least three times a week, usually four or five (I refill the chow twice a week and offer fruits/veggies at least twice a week). Water crystals usually twice a week, but any time they are close to being gone. I admit there have been times where I open the bin and they've pretty much completely demolished the crystals in a short amount of time, which makes me worry.


I ask because I read a post that made mention of cannibalism, but I haven't read anything like that in the care sheets I have read. I'm concerned because my colony seems to be growing and shrinking, and I keep the adults and nymphs together. If this is true, I may need to have a stricter schedule on separating them. Let me know!

[JeffreH]

There are some roaches in the Blaberus genus that seem to be more prolific under higher population densities; which is often a rarity in most organisms. Overcrowding, pheromone bombardment, intraspecific competition for resources, etc all add some amount of stress to cockroaches (and most any other species, for that matter). This stress can encourage things like small body-size and cannibalism in your bin.

Blaptica dubia will cannibalize their offspring or freshly molted individuals if the need exists. How dense is you population in the bin? The need to separate nymphs isn't too great, but you will notice some population benefit if you take the time to do so as newborn nymphs are the most delicate of all instars. Cannibalism shouldn't result under the conditions you're providing so long as there is plenty of space. And while B. dubia can be cannibalistic, it isn't going to make a significant impact on your colony. Maybe a couple of nymphs per litter on average... these guys really aren't a major threat to themselves at all. Compare a B. dubia colony to an E. posticus (orange head) colony under the same conditions and you will be shocked at just how cannibalistic a different roach species can be.

The other thread you were referring to I think discussed keeping two separate species together; G. portentosa and B. dubia. The prior will more readily cannibalize cage-mates for the same reasons I've mentioned in the first paragraph. The two can be kept together with success, and can even maintain decent fecundity, but they often need more attention in the resources department to discourage interspecific competition. I've heard that cramped conditions and excessive pheromone production can sometimes have negative effects, but I don't have the data to back this personally. The ticket is adequate space, food, and likely most importantly, moisture.

If it makes you feel any better - I have a couple of B. dubia bins that I only get around to feeding once a week or so...maybe once every couple of weeks. I'm allowing for some self-thinning while there is a surplus in other cultures. Despite being fed and watered with extreme infrequency, the colonies are still viable and producing offspring. Adults are suffering and clutch sizes aren't as high, but the population is at least stable. Given the care you are providing to yours, I wouldn't be too concerned ; ) If you think things are too crowded, consider setting up another bin. Here is an example a bin that is too crowded that I needed to separate out:

[unkempt1]

Uh yeah... mine doesn't look like that. Thanks for your expert perspective, as always, Jeff!!!

[yoshimi]

Jaw-drop. How did that happen? Just a lot of letting it go? And for how long? I guess big snakes don't eat roaches...? Rather than letting some bins self-thin, could you give some away to friends? Personally, I have no friends with reptiles or frogs. NONE. I need better friends.

I lifted up an egg crate tonight and a brand new (still had some casing they were connected to and eating) was there. I think it may have been underneath crate and fallen. Oops. So I had brand new babies that went running around. They should be fine, as I had new pale babies running around last night. I was surprised, thought they stayed under mama for longer. She was a small (short in length) roach, so her litter was maybe 10. Tho they were running around they were easy to spot, obv. I'm eager for the longer ladies and the crazy baby explosion that will come from them.

You say maybe a couple on average per litter might be eaten? :O By my shocked face, you can see that I didn't know that. I think I'll be doing another nymph removal tonight, before I get too tired to do it well. Maybe I'll wait til morning.

Oh, and are red runners worth trying? Nutritionally, how do they compare to dubia? I guess I could look that up. I'm extremely hesitant to try them with "runner" in their name. I'm semi-clumsy (being nice) and a little dubia or even a cricket (sometimes), I can catch, but something running across my kitchen and under the sink where I can't get to it would bother me. Cuz when you drop one, chances are you'll drop another eventually.

[JeffreH]

I should clarify - you really shouldn't see cannibalism in B. dubia so long as you are providing adequate moisture and food resources, and space. In the event that they do start to become stressed or overcrowded, you'll start seeing slightly smaller litters and sometimes a bit of cannibalism (hence my speculation at a couple of roaches per litter). In the long-term, adult body size is sacrificed when conditions aren't ideal. You can get a feel for when you are stressing out the cockroaches by looking at the quality of the adults and the size of the litters. In smaller cultures under good conditions, cannibalism in this species is essentially nonexistent. My example with the Orange Heads (E. posticus) was a comparison under even ideal conditions, where the orange heads will readily munch on each others wings at almost all times, and who will cannibalize each other rapidly under stress. So in terms of cockroaches and being a threat to themselves, B. dubia are not comparatively to other insects. I rarely separate nymphs from adults and have never had an issue with a colony eventually booming out of control.

Speaking of booming out of control, LOL - that particular colony pictured is the result of "neglect", believe it or not. I have a heated rack system for my cockroach collection, and the more exotic species have first priority. Adjacent to this, I keep my largest bins with the feeders, such as B. dubia and E. posticus. Once the colony hits a size of about 10,000, they probably need separated into separate bins. I began doing this years ago with B. dubia and these particular bins are kept cooler (around 80 degrees) and are fed only about once a week. Believe it or not, that colony started as about 2500 individuals and over the course of about a year, maybe year and a half or so attained a weight of 21lbs of pure, living cockroach meat. I don't even want to imagine how many roaches would have been produced if I had kept them warmer and tended to them like I tend to the others.

My herp interests have changed over the years; I used to breed geckos and during this time roach production was essential. Over the last few years, my interests have shifted more heavily into pythons and boas, and I ended up moving quite a large chunk of my insectivores. I actually do give a lot of cockroaches to friends - I've ditched my turkistan colonies (lats) on a frog friend and moved most of my lobsters to a guy in Utah. That particular bin with all of those roaches was sold years back to a friend in Kentucky who was starting to breed bearded dragons...and anyone who has raised a baby beardie knows just how much they can eat in a single day. A juvenile bearded dragon was actually the reason I started looking into cockroaches in the first place - they are bottomless pits and I was sick of buying 1000 crickets a week to feed. That being said, when colonies are out of control nowadays, I pretty much just leave them be. When the weather is nice and if I can get the free time, I'll do some counts and may make them available, but roaches have already provided me with a great return on investment in both feeder and cash form.

Red Runners AKA Turkistan Roaches (Shelfordella [Blatta] lateralis) are excellent feeders. Interestingly, cockroaches don't appear to differ much in overall nutritional composition. Blaptica dubia and lats are almost identical in protein and fat composition, and are likely very similar in their calcium: phosphorus and chitin mass.
Feeder Insect Analysis

They are fairly quick, but they cannot fly or climb smooth surfaces. They also lay oothecae in the open environment rather than self-incubating, which makes things a little trickier as well. I've found they perform best with a substrate for reproduction and to prevent the ooths from drying out... getting the humidity just right can take a little tweaking. Once you've got the system down, they breed like mad. Personally, I think they are a better species for herps who are very visually stimulated. Dubia frequently bunker down and some herps lose interest rapidly in them as a result; and lats usually do a bit of scurrying before they run off to find a hiding place somewhere in the enclosure. They also seem to be softer bodied and less scleritized than dubia, which may improve overall meat: shell ratio.

I think that covers just about everything for now = )

[yoshimi]

Everything and more. I'll think I'll stick with my dubia. 1st thing I read last night was a warning to NOT let a red runner escape. I wouldn't be breeding them anyway, I didn't plan to breed dubia but I won the set so I went for it, even tho I was conflicted. Now I find them enjoyable. I separate babies cuz that's what I feed and when they're that small I can't really feel them crawling on my fingers, so the less in adult bin when I have my hands in there, the better. Of course, can never get them all, and wouldn't anyway, as I want to keep things going a little (not a lot).
I meant that the shorter female had a small litter, but I have some preggo ladies who are much longer in the body, and I imagine their babies are more plentiful, and since they're holding still, maybe bigger when they pop out. Perhaps that's why the 1st litter in breeding bin stayed under mama for so long, and new ones go wandering. More incubation time, bigger babies? Eh.
I actually like that dubia play dead. Not as bad as crickets who all freeze at once (but never when you're trying to pluck them out of their cricket bin). The roaches run around in Banjo's food dish, she eats, then if a few are left over staying still, she can come back later and get the rest. It hasn't been an issue. She's a big eater, but no, she's no baby bearded dragon (which is on my wishlist).
Glad to know, as Augie, that my dubia aren't chowing down on each other when I'm not looking. I have a small, manageable colony and plan to keep it that way, so phew.

[demon amphibians]

I could not agree more with Jeff when concerning cannibalism. I could not have said it better. I posted to a thread that two member's were convinced that if you mixed Madagascar hissing roaches with dubia's that the hissers would eat the new born dubia's. It lead to a pretty heated argument which was pretty funny. What Jeff stated is exactly correct. If you don't have conditions right then and only then will you see cannibalism. If you don't have proper moisture levels even adult dubia's can become victims of cannibalism. Now it may seem like male dubia will chomp at each others wings and become to look very sickly. This is not cannibalism this is a result of to many males in one enclosure. These guys will fight like cats and dogs if they out number the females. That is why I always stress the importance of keep them at least 3 female to 1 male. But even with large amounts of males in one enclosure I have yet to see a death result from the male aggression. I also agree with Jeff on the over population part too I have witnessed very little cannibalize just because I have well over 10,000 in one bin. I just upgraded to 3 bins one for the breeders one for the mixed size nymphs and one for the new born nymphs. I have let my colony grow for about 15 months feeding only extra males to my frogs, toads and turtles. Now its looking like I will be need a 4th bin because I have so many breeders. I hand counted my female and male breeder bin last month just to have a better idea of how many males I needed and I counted 1025 females. I clean my bins every 2 weeks and every time I pull out 70-150 mature females of my mixed size bins and transfer them to my breeder. I would say I have roughly 1250 females with 300 males. And lately I have noticed that these these guys need more space then previously thought. I mean a lot more space. And I can see it through the numbers that I am breeding at, I average about 5000-7000 newborns a month were I should be seeing numbers closer to 18000. So what I am going to do is divide my breeder bin in half to two bins of the same size, give it two months and then I will let you all know the difference in reproduction. I will also need a 5th bin for my midsize bin because it is getting so cramped. My bin isn't small either it is 36 gal. And my two breeding bins are 25gal. So for all you who are starting out with your new colonies keep in mind they will do better with more space and this will help reduce that small amount of cannibalism. I will keep you all posted on my results as well as when I will do my give free give aways.

If you are reading this and wondering why I have so many roaches. Its because I plan on breeding cane toads and American bullfrogs and if I have thousands of little frogs hopping around before I can sell them I will need a lot to feed. But since I have been so successful breeding dubia's and I am enraged with the market price of them, I have choose to sell them as well.

Good info Jeff it is good to find a seasoned roach breeder in the community.

[Heatheranne]

I too have never witnessed any cannibalism in my colony. Not near as large as you fellas, I have about 750 or so. I did, however, move them from the cramped 10 gallon to a 20 gallon long tank. And I turned their heat lamp down a bit to slow their breeding .

I do have to say that my American bullfrog LOVES them...they're his favorite . My pacs love them too.

[Heatheranne]

I would say those are some pretty close numbers. Oranges will for sure influence this though. They will molt and mature at different times as well as mate at different times and berth at different times so your males should always have something to DO if you get my drift.
I think it is so cool how personnal you get with these things. I almost think when it comes feeding time your going to have a guilt trip feeding them to your frogs lol. But hey all of my roaches are my pets as well. At least for now . And they are such a peaceful insect. I never thought i would say such a thing about a roach. Heck I was very close to not getting them at all. My idea of roaches were they are just dirty little Basturds. Lots of entertainment.

Isn't that the truth! Lol! I thought the same. When I first got mine I couldn't even touch them. Now I sort through them looking for nice freshly molteds all of the time. So much better than stinky, biting crickets.