Many questions about dubia colony from confused newb

[Temjeito]

I recently started my first dubia roach colony, with about 75 small dubias (about 1/4" to 1/2"), 10 adult females, and 5 adult males, although one of the females died within a few days, possibly giving birth (see picture)? I find many dead smaller dubias every day (although I'm not sure how many are molts as opposed to dead bodies). The other day I introduced lesser mealworms and dermestid beetles. The next day I found many dead lesser mealworms (see pictures). So far I've found only one dead dermestid. I am also finding lots of small, rock-hard things that at first I thought were nymphs or eggs but they are rock-hard. Maybe frass from the adults? My eyesight isn't great.

I'm brand new to this so I'm not sure if any of this is cause for concern. They are kept in a 12-gallon opaque storage bin with a lid with a screen in it. and a bunch of egg flats from Josh's Frogs stacked inside. The bin stays in my closet where the temp is probably in the mid-70s most of the time. I've fed them Josh's frogs "roach rations", "dubia diet" from dubiaroaches.com, and a variety of fruits and vegetables (all washed). Lately I've also been putting in "water crystals".

Most importantly, I want to know whether I should be concerned about feeding my slings or scorpion with these dubias and, if so, what you would suggest I do. Any suggestions or constructive criticism would be appreciated.

Also, any tips on how to find and grab the nymphs/smallest dubias? They seem to hide in the frass/dry food and my slings are still pretty small (about 1/2") and I'm finding it hard to find roaches that are 1/4 inch long (the 1/4 inch ones I put in a few weeks ago have grown!)

Dead mama roach:

Dead mealworms & smaller roaches:

largish hard things:

 

[boina]

I actually have no idea what could be killing your lesser mealworms but I have a few general remarks:

From my own experience keeping a large Dubia colony for nearly a decade - lesser mealworms are the bane of my existence when it comes to Dubias. It is actually rather difficult (or extreme luck) to have a balance between the "cleaner crew" and the Dubias. The Dermestids usually die and the lesser mealworms take over the colony, eat all the food and crowd out the Dubias and if I could manage to get rid of the <edited> things I would be exceedingly happy. My strong advice would be to NOT introduce any "cleaner crew". A well kept Dubia colony doesn't need any. Just keep the Dubias dry (and if you feed fruits and veggies you definitely don't need water crystals), clean them out every couple of months and you are golden. And a mix of oat meal and ground cat or dog food makes for a complete and cheap Dubia food, especially when you augment it with said veggies and fruits.

 

[Temjeito]

Thanks for the tips! I guess having the mealworms die is not the worst thing (assuming it's not a sign of something worse). How many dead dubias would you say is normal for a colony of this size?

 

[boina]

Thanks for the tips! I guess having the mealworms die is not the worst thing (assuming it's not a sign of something worse). How many dead dubias would you say is normal for a colony of this size?

Very few. I rarely have Dubias die on me, except from old age, meaning nearly all dead Dubias I find are adults.

 

[Temjeito]

Very few. I rarely have Dubias die on me, except from old age, meaning nearly all dead Dubias I find are adults.

 

[Malum Argenteum]

I keep a heat mat under my colonies, covering about a third of the bottom of the bins, set at about 85F.

I'd skip the 'water crystals', as they're unnecessary. I also weed out 'cleaner crew' insects as I find them.

I find dead ones sometimes. No big deal. The colony increases in numbers, so I'm satisfied.

 

[Temjeito]

I keep a heat mat under my colonies, covering about a third of the bottom of the bins, set at about 85F.

Is it a sterilite type bin? I worry about melting the plastic.

I'd skip the 'water crystals', as they're unnecessary. I also weed out 'cleaner crew' insects as I find them.

I’m going to move them to a bigger tub so it’s easier to get at them. When I do that I’ll try to weed out the cleaners. Not sure what I’ll do with them after that though

I find dead ones sometimes. No big deal. The colony increases in numbers, so I'm satisfied.

Yeah I’m less worried about the colony (I’ve got way more roaches than I need) and more that something is killing the critters that could harm the Ts or scorpion.

 

[boina]

Is it a sterilite type bin? I worry about melting the plastic.

You can use a heat mat, but you don't need to (I don't). Dubias actually have quite a temperature range they thrive in. They will definitely breed and grow faster if you raise the temp, but 75F is good enough for them to slowly breed. If you use a heat mat you could keep a bit of space between the mat and the box to avoid heat building up.

 

[Malum Argenteum]

It is like a Sterilte bin (made by Vision -- I think it is polyethylene). No, plastic doesn't melt at 85F. Heat mats always need to be on a thermostat or at least a dimmer (inline slide-type dimmers work fine), periodically checked with an IR temp gun. I provide a heat mat because wherever possible, it is preferable to provide a thermal gradient for animals to choose from (this is a pretty foreign concept to captive T keeping, and I sure wouldn't recommend it for captive T keeping for a bunch of reasons, but for bins of roaches I find it useful) but as boina says it certainly isn't necessary at 75F. If you have winter where you are, then it might be.

Your concerns are understandable, but it is most likely just random deaths. I'm not sure what else it would be. Take 100 of any living thing, shake them around in a box for two days (you got the roaches shipped to you, I assume) and pour them into a box at a different temperature than they're used to (I guarantee the breeder is pushing production as hard as possible) and there will be some deaths.

I breed my own roaches, but I order in about 20k mealworms a month, along with superworms and occasionally crickets by the thousand count, and the random hornworm cups and fruit fly cultures and there are definitely deaths, sometimes entire crashes a few days in. Roaches are more durable than any of these other feeders, but shipping and transitioning to new conditions is stressful.

 

[Smotzer]

In all my colonies I have never had deaths on a daily basis, that seems very odd to me, they are hardy critters. But it could be due to how they arrived to you.

 

[Malum Argenteum]

I find many dead smaller dubias every day (although I'm not sure how many are molts as opposed to dead bodies).

If you're checking every day, you should be able to sort freshly dead roaches from molts based on their weight -- molts are just the exoskeleton, while dead roaches have relatively heavy tissue inside.

Experienced roach keepers: is there predation by roaches that are seeking protein? I know the tendency nowdays is to feed lower-protein food, and I know that roaches will eat the wings off adult males when they're underfed or overpopulated generally, but might a higher protein food be worth a try for the OP? That Josh's product lists 15%; the stuff I feed claims 21%, and I'm sure the commercial breeders feed more protein than that.

 

[Temjeito]

Update: I moved the colony to a larger bin and pulled out as many of the cleaners as I could. I think most of the "bodies" were actually molts, based on the weight (thanks, Malum!), but there were still quite a few dead little guys. They don't seem to be eating much of the dry food, so Malum you could be on to something with the protein theory. I put in some dried shrimp that I feed to my beetles and we'll see if they eat that. I will also try crushed dog food.