Darkling beetles dying?

[Harmonicon]

Hello! I keep beetles (specifically CA darklings) and they just randomly die on me.

I had like 8 in total and 3 of them died. Before they died, they were in the "fake death" position and when I flipped them over, they moved a bit, and then stopped. The next day, they die with a liquid coming out of their mouth.

I feed them Brussel sprouts, carrots, blackberries, blueberries, and strawberries all blended together. I also give them water crystals for extra moisture and also have old bearded dragon pellets, some of my mice's food, and some bird seeds. I keep them on 1/3 topsoil and 2/3 play sand.

Please help, I do not want them to keep dying.

Thanks.!

 

[InvertebrateGuild]

Can you provide a picture of your enclosure? They may be dying of age, perhaps the species you are keeping has a short lifespan in it's adult form. However, the liquid coming from their mouth may suggest otherwise. In my experience, when beetles die of age, they simply lay down somewhere dark, and die. No flipping over or liquid. I know that many darklings can emit a black liquid from their mouth parts as a defense to predators, and have observed it with my Smooth Death-Feigners. Therefore, I have no idea why your beetles are dying.

The diet you offer seems okay, I've used all of those foods except brussel sprouts to feed before. Perhaps try removing the sprouts from their diet and seeing if anything changes. I know that certain vegetables can be toxic to certain invertebrates, though that may not be the case here.

If you could provide additional information about your enclosure (contents, location, heating/humidity (if used)) and how you generally care for them, someone may be able to find an answer.

 

[Harmonicon]

Can you provide a picture of your enclosure? They may be dying of age, perhaps the species you are keeping has a short lifespan in it's adult form. However, the liquid coming from their mouth may suggest otherwise. In my experience, when beetles die of age, they simply lay down somewhere dark, and die. No flipping over or liquid. I know that many darklings can emit a black liquid from their mouth parts as a defense to predators, and have observed it with my Smooth Death-Feigners. Therefore, I have no idea why your beetles are dying.

The diet you offer seems okay, I've used all of those foods except brussel sprouts to feed before. Perhaps try removing the sprouts from their diet and seeing if anything changes. I know that certain vegetables can be toxic to certain invertebrates, though that may not be the case here.

If you could provide additional information about your enclosure (contents, location, heating/humidity (if used)) and how you generally care for them, someone may be able to find an answer.

Sorry, I forgot to update this post! I switched their diet to only water crystals, mouse food, and occasionally carrots! Seems great and none of them are dying. Thanks for the reply!

 

[DaveM]

This is interesting. Brussels sprouts are very high in oxalic acid, which is a known antifeedant that deters some beetles, but not others. I saw a test report somewhere that Chrysomelids were differentially affected: Leptinotarsa (potato beetles) were deterred and some fraction of them died, while Callosobruchus (bean beetles) were unaffected. I don't know about darkling beetles. Of course it could just be some pesticide. If your colony is large enough, you could experiment to find out if it really is the Brussels sprouts.

 

[connieisdead]

This is interesting. Brussels sprouts are very high in oxalic acid, which is a known antifeedant that deters some beetles, but not others. I saw a test report somewhere that Chrysomelids were differentially affected: Leptinotarsa (potato beetles) were deterred and some fraction of them died, while Callosobruchus (bean beetles) were unaffected. I don't know about darkling beetles. Of course it could just be some pesticide. If your colony is large enough, you could experiment to find out if it really is the Brussels sprouts.

I wouldn't have guessed that Brussels sprouts would be too harmful but after some Googling I think you're right about them being toxic to some species.