Molting problem with a Mexican Red Rump

[Ratmosphere]

Sorry for your loss.

 

[AndrewClayton]

Have a read at this before going any further, I think it should help you out, with the humidity and that as there pretty irrelevant.

So you want a Tarantula!

So you want to get yourself a Tarantula, hopefully it's a New world. So what is meant by new world?, you may ask. The New World, is, the Continent of America, these Tarantulas are generally more docile and advised to start with, they have Urticating hairs that can be kicked off in defence, and...

• AndrewClayton
• Mar 8, 2025
• Category: Tarantula and Invertebrate Care Basics

 

[Papaya]

Sorry for the confusion with the name. It's my first time posting. Her mouth parts look fine, so I figure I'll just baby her for a while. I did recently add some moisture to the soil.

Any update?

 

[Eighth Eye Blind]

I know that this is an older thread and I'm kinda throwing a curveball at it, but . . .

The fact that two individuals with the same problem came from the same pet store raises the specter of insecticide poisoning.

Neonicotinoid insecticides like imidacloprid are found in some flea and tick collars and medications (e.g. - Seresto, Advantage, etc.). This class of pesticides isn't as generally toxic to spiders and other invertebrates as some chemicals, but they do have nasty non-lethal effects.

One of those nasty effects is a breakdown of the cuticle and separation of the epidermis from the endocuticle. (Or, in regular person language, the exoskeleton gets detached from the internal tissue with fluid filling up the space between them.) Although I’ve never seen the effects of this in person, I’d expect it to look a lot like what happened to your T’s legs during their molts.

Imidacloprid also causes generalized weakness and temporary paralysis in spiders that would lead to trouble molting as well. Neonicotinoids are also known to affect molting and post-molt mortality in blue crabs so there’s evidence of these effects in other inverts.

It’s therefore possible that the shop where you got them was using a flea and tick treatment containing imidacloprid on some of their furry offerings and it ended up contaminating the tarantula enclosure. This is really easy to do by not washing hands after handling some puppies and then going over to take care of the spiders. Looking at what happened to the two T’s that came from the same source and knowing what (little) we do about the effects of imidacloprid I’d say there’s at least a chance that it’s the villain that got to your T’s.

I’m really sorry you lost those animals. I hope that you’ve been able to replace them.

 

[Tarantula Trooper]

I know that this is an older thread and I'm kinda throwing a curveball at it, but . . .

The fact that two individuals with the same problem came from the same pet store raises the specter of insecticide poisoning.

Neonicotinoid insecticides like imidacloprid are found in some flea and tick collars and medications (e.g. - Seresto, Advantage, etc.). This class of pesticides isn't as generally toxic to spiders and other invertebrates as some chemicals, but they do have nasty non-lethal effects.

One of those nasty effects is a breakdown of the cuticle and separation of the epidermis from the endocuticle. (Or, in regular person language, the exoskeleton gets detached from the internal tissue with fluid filling up the space between them.) Although I’ve never seen the effects of this in person, I’d expect it to look a lot like what happened to your T’s legs during their molts.

Imidacloprid also causes generalized weakness and temporary paralysis in spiders that would lead to trouble molting as well. Neonicotinoids are also known to affect molting and post-molt mortality in blue crabs so there’s evidence of these effects in other inverts.

It’s therefore possible that the shop where you got them was using a flea and tick treatment containing imidacloprid on some of their furry offerings and it ended up contaminating the tarantula enclosure. This is really easy to do by not washing hands after handling some puppies and then going over to take care of the spiders. Looking at what happened to the two T’s that came from the same source and knowing what (little) we do about the effects of imidacloprid I’d say there’s at least a chance that it’s the villain that got to your T’s.

I’m really sorry you lost those animals. I hope that you’ve been able to replace them.

Valuable information! Thanks for sharing this! My older son doesn't interact with our T's so he handles all the de fleaing of our cat. I try to be mindful to wash my hands before dealing with the spoods but it's easy to forget. I am going to make an extra effort to remember this after petting my cat!! Lol ! Thanks again!