Dubia nymphs keep dying off

[Eratigena Atrica]

Hello, my Dubia roach nymphs keep dying off.
The conditions are great and I feed them vegetables, Fish flakes and oatmeal.
The adult roaches are doing well, also the juveniles but the nymphs are extremly weak. Some lying on their backs and don't move at all.
What could they have?

Best regards

 

[Ratmosphere]

How's the temps? Do you offer them any other water source?

 

[Eratigena Atrica]

They are in constant 26 C. The water source is a water filled cotton pad. Only the smallest nymphs keep dying. I have no idea what the reason could be.

 

[The Mantis Menagerie]

Do you wash their vegetables? Maybe the nymphs are susceptible to a pesticide on the food?

 

[Eratigena Atrica]

Yes, I do wash my vegetables and fruits. I never see them outside of their egg cartons to drink or eat. Is that normal?

 

[richard22]

Maybe clean out and transplant the enclosure, perhaps some type of bacteria could harm them if the cotton pad is not washed, maybe zoonoses of some sort. Pesticides shouldn’t be an issue for a 2nd gen roach, especially if you wash produce well, the roaches should be immune to the pesticide if the food is the same as was for the adults before birth, roach pesticide issues aren’t as much of an issue since resistance develops over time if the pesticide weeds out the vulnerable roaches leaving the resistant ones only. If you don’t heat the enclosure much you could try water gels or water pillows as they are cleaner, but more expensive and temporary when the dry out in heat. Probably don’t let frass accumulate too much and be weary of invaders in the oats, flour/grain mites are common if the humidity is high and they can destroy the edibility of food, clean out moldy produce or food asap.

 

[Eratigena Atrica]

I always change the watered cotton pads, wash my vegetables and fruits and clean the enclosure once the week. Is this a gene thing? What could that be?

 

[indyana207]

I've been told the smallest nymphs eat frass. Is there at least some in there for them to eat? That's my only idea other than mold or dehydration.

 

[mantisfan101]

HAve you tried giving them a source of protein? I find fish flakes and dog food to be the best. The majortiy of my hatchling roaches would eat those.

 

[Eratigena Atrica]

To answer your questions: I give them twice the week dry cat food and they've got a lot of frass. I make sure that they become not too much protein since I've read somewhere that too much could be dangerous to them. I got new juveniles two days ago and today one of them was unusually slow. I've feeded them skinned grapes. Are grapes harmful for them?

By the way: Thanks for all your replies

 

[richard22]

I've feeded them skinned grapes. Are grapes harmful for them?

I don’t know myself but here is an older quote on another thread, put it in quotes on Google if you want to read the whole thread: „Watermelon and papaya would be excellent. Cantelope and bananas are also good choices. Pears and apples don't seem to be as appealing to any of my roaches although they'll still eat it if that's all they have available. They don't really go for grapes either. I think the only reason why you don't hear many people using those to feed their roaches is because those fruits are more expensive than the usual apples and oranges. My only recommendation is that if you have a small colony, only offer what they will finish within two days, which might only be a few small pieces. Otherwise, the leftovers get yucky and moldy. Its also a good idea to cut up the fruit and distribute them around the cage so you get more surface area.“

So melons or oranges or grapefruit might be a good choice but grapes aren’t harmful to my knowledge, along with maybe some potato/carrot slices, be sure to wash all produce off to prevent pesticides from killing the roaches; never feed celery because that killed some of my roaches in droves or just be extra vigorous washing leafy greens. Cut skins off if is not a burden to do so, or just use the hard side of a sponge on whatever produce you wash. Citrus might increase breeding judging from someone’s experience on the thread I quoted. Watermelon might get their water requirements without supplemental moisture but will certainly dry out FAST in high heat (from heat lamp or space heated room) if you want the fastest growth and breeding. Potatoes don’t dry out as fast because of less moisture but aren’t sweet nor give water requirements. You probably should do oranges and maybe melon if heat isn’t too high unless you can replace food often or don’t always want available fruit, or use potatoes or carrots if fruits dry out too quickly. I haven’t tried feeding fruit but I’ll start doing it today and see what happens. DON‘T OVERFEED, just cut fruits and/or vegetables thinly (or thickly if your colony is large) and place them in some areas the roaches congregate, otherwise the food could be infested with grain/flour mites; not overfeeding is especially important for when grain foods are fed and when moisture is high and ventilation is low. Roaches tend to not need high humidity so try to get good ventilation in the lid (like a netted lid) if you don’t already have high ventilation.

 

[EulersK]

I always change the watered cotton pads, wash my vegetables and fruits and clean the enclosure once the week. Is this a gene thing? What could that be?

Can we see a picture of your setup? Gotta say, you seem to be working way too hard on the dubia colony. I've got ~40 colonies and have been selling them as a part time job for years now. I typically clean the enclosures once every 6-8 months unless something really goes wrong. I don't know if there's much credence to nymphs actually eating the frass, but they certainly burrow in the stuff. Remember, this is a burrowing species of roach.

Having a healthy layer of frass is, I have found, paramount to their health. Firstly, these animals are cannibalistic. It is usually the nymphs that gang up on and eat the weak/dying adults, but I have witnessed several times adults happily munching on newborn nymphs. Having that layer of frass gives the nymphs somewhere to go and grow in peace, away from their peers 20x their size. Secondly, being roaches, individuals of all sizes will easily die if they fall on their back. If this happens and they don't have some kind of substrate to help them kick themselves back upright, they will quickly die of exhaustion. The substrate can really be anything you want - topsoil, grain food, frass - but I've found the former two simply make a mess and the latter allows for easier cleanup. Lastly, I'm sure you're concerned about a smell. Let me make this clear: If your dubia colony smells, you are doing something wrong. Obviously there will be an odor if you stick your head in the colony, but by no means should you smell it from more than a foot or two away. By far the biggest and most common error I see is people simply drilling a few holes in the lid of the container and calling it good. Not enough. I cut out the middle of the lids and hot-glue window screen for ventilation. Your egg flats should be perpetually bone-dry. If they feel moist or limp, then your humidity is too high and you run the risk of mold and death.

As for food, you can make this a lot cheaper on yourself. A 40lb bag of chick feed (not chicken feed, chick feed) runs about $30 where I live, and that lasts me about 4 months for all my colonies. Very high protein as well as high fat, not to mention all the additional vitamins and minerals. As for fruits and veggies, many supermarkets have a clearance produce section. I'm typically able to get a huge variety of fruits for just a few dollars. Don't be afraid to ask the produce clerk if they have any fruits that need to be marked down or thrown away. I used to work in a grocery store, and let me tell you, there is always a pile of produce in the back ready to be thrown out! The manager is usually thrilled to actually sell it rather than throw it away. I wash the produce, cut it into chunks, and freeze it. This makes feeding them easy and mess-free. Toss in the chunks while they're still frozen. Easy. My roaches have 24/7 access to chick feed (which is just poured directly onto the frass along the sides) and a feeding of fruits/veggies once every other week. I have found their favorite foods are oranges, tomatoes, and any type of squash. Anything high in vitamin C will make them reproduce quicker. Root vegetables tend to not be a favorite, and surprisingly, bananas are largely ignored except for the peel. This method of feeding gives them a massive variety in diet, and is much easier on your wallet than what you're currently doing.

For water, while the cotton ball is essentially free, consider picking up plant water crystals. It will allow you to change it much less frequently. 1oz of dry crystals makes 1gal of water crystals, which will last you a long time. Any hardware store that sells plants will have it, and you can pick up a pound of the stuff on Amazon for about $25. Just make sure that your water dish is rough on the outside and inside so they can climb in/out. I just cut a deli cup and rough it up with sand paper.

 

[Eratigena Atrica]

Here are the pics:

 

[Eratigena Atrica]

Is everything ok with this enclosure?

 

[indyana207]

Usually keep mine with more frass on the bottom and in a dark container. Not sure how light sensitive B. dubia are. Also, make sure they always have food and moisture sources.

 

[richard22]

I’d recommend splitting the egg flat into smaller pieces you could stack, therefore they won’t fall off and they’d have more hide. Once the culture gets large you could focus on efficient space so maybe you’d want to have it like that but on its side stacked horizontally. If your culture is small you don’t need to have so many full egg flats unless you plan to expand a lot so to save on space, I don’t know if having too much space is a problem though.