# [NSFW] Mantis post-mortem; sudden death advice needed!



## nzxmUyZNKEBoqN3e (Jul 31, 2020)

_*As indicated by the title, this post will contain pictures of a dead mantis and it's innards - if you've clicked on this by accident and don't want to see it, here's a picture of a cute cat so you don't see anything you don't want to!*_







*You've been warned  *

I posted on here recently about a bizarre abdominal curve taken on by my Cilnia Humeralis, Stefanie. After receiving advice from on here and from her breeder, it seemed that this was not to worry about. Things carried on as normal over the next few days (with a reduced feeding plan to see if that would affect the curve at all), with activity and defecation carrying on as is normal. Unfortunately, things took a turn for the worse; over a period of about 12 hours, her situation decreased rapidly to the point where she could no longer support herself or her abdomen.






_Image 1: By this point she was essentially dead, unresponsive to most stimuli_

Upon flipping her over to inspect the discolouration that I had previously posted about, I saw this:






_Image 2: Notice the blackening on the underside of the abdomen; it is meant to be the same colour as her torso_

She struggled on for a little while longer but eventually succumbed. This is how I lost my first mantis, an Orchid; however in that instance this took place over a period of 5 days. As such, I decided to open up her abdomen to see what I could discover, in order to hopefully learn something that would help me prevent this from happening again. Whilst being sure that she was dead, I left her in the freezer for an hour or so to ensure that as I couldn't live with myself if she was still alive when I cut into her. 

I first noticed how squishy her abdomen was; I didn't make a point of squishing it whilst she was alive so I'm not sure if that is 'normal' or not. Before commencing with the post-mortem, I was expecting that this was a bacterial infection and that it would smell terrible. Indeed, it didn't smell good but it wasn't as strong as I had expected, nor did it smell as I had predicted - it was more of a fecal smell than one of rotting, or infection.






_Image 3: First look inside the open abdomen_

Image 3 shows the abdomen opened for the first time - there is a significant amount of black substance there. After visual inspection, I carefully dabbed at it with some toilet roll to see whether it was rotten insides or fecal matter - the substance came away easily with a lilac liquid as well. I don't believe this to be blood/hemolymph as apparently insects lack red blood cells/haemoglobin which means their 'blood' is clear. It may well have been digestive juices, but I've no way of knowing. Because it came away easily, I suspect that this was fecal matter/ food in the process of digestion. 






_Image 4: Abdominal interior post cleanup_

There was a significant amount of material that came away with cleaning of the abdomen, which I assume would be food. She had her last moult on the 21st of July, and had eaten 3 black soldier flies since then - given that she didn't eat for a few days before her moult, that's roughly 3 flies in 15 days. There was a significant amount in her abdomen that had not been passed, even though she was defecating fine - even when I retrieved her body from her enclosure, she had some fecal matter stuck to her rear end. This seems bizarre, as (I believe) a common symptom of gut impaction is that nothing can pass through the digestive system as it is blocked. Image 5 (below) shows the paper towels that I used to clean her interior. Her abdomen seems awfully white in this - that is as a result of the autopsy and was not present beforehand.

Now, moving onto the analysis stage, where I will hopefully present every facet of her life and suggest a cause of death.


*Habitat* - Stefanie lived in a 5 litre mason jar. Mason jars are not ideal habitats because they are hard to clean and do not facilitate easy ventilation; indeed, humidity was a struggle. I attempted to remedy this by creating a 'dome shaped' lid that protruded by about 10cm from the jar. This gave roughly 3.8 times the amount of surface area for ventilation as opposed to a flat lid. Her habitat was next to my violin mantids and was shone on by their UV lamp, however this had no effect in terms of secondary heating and I do not believe that it was harmful to her in any way. I had not recently introduced anything new to her habitat, bar a few new sticks that I had boiled for half an hour to sanitise. Inside her habitat is a small fern, a few nerve plants (fittonia albivenis) and a polka dot plant (hypoestes phyllostachya). These had all been present for months and had caused no problems. About a month ago, I removed a dwarf umbrella tree (schefflera arboricola) from her habitat as it was not doing well. Her habitat is bioactive, with a healthy population of springtails. The habitat was misted daily with deionised water. Cleaning the jar, as mentioned, was difficult and I did not take the opportunity to do full cleans (including substrate changes) very often; I was confident that between myself removing dead carcasses and the springtails, that the enclosure was suitably clean. Given all that I have presented here, I am satisfied that her death was not caused by the plants in her habitat however I cannot rule out infection from higher humidities or unintended uncleanliness as a cause of death.

*Diet* - like my violin mantids, her diet consisted of either black soldier flies or green bottle flies, depending on what was alive at the time. She never ate crickets or wild caught insects, and I never fed her any fruit or honey. She was a voracious eater and graceful huntress. The diet is both concerning and calming to me; my Orchid mantis died whilst she was on a primarily BSF diet, however my violin mantids have happily subsisted on them as well and are showing no signs of illness whatsoever. Indeed, BSF are a common feeder and whilst there are limited papers about their use as animal feeders, I can find no other reports of harm from people feeding black soldier flies. One paper I did find did mention that their hard calcium exoskeleton did impede digestion in their experiment (which was conducted on geckos) but I feel that there would be more posts about this if BSF posed a threat to mantids. From my opinion, my own circumstantial evidence suggests that black soldier flies are not healthy feeders however looking wider than my own experience, it would seem that this is purely luck (or indeed lack of it).

*Outside factors* - I have always been very careful with what I expose my mantids to. I don't use any spray deodorant or products in the room they are kept in and I clean their enclosures with deionised water. Given that this appears to be an infection as opposed to a chemically-induced death, I am happy to rule this out as a cause of death.

Having presented all the evidence, I believe that her death occurred either as a result of infection, from either her food or her environment, or as a result of gut impaction from difficult-to-digest feeders. On the balance of probability, it seems to me that it was likely that her death occurred due to an infection from her environment as that is where my greatest failings in her care occurred.

To remedy this, I shall no longer be using mason jars as habitats. I had previously planned to transition away and Stefanie was due to receive a handmade acrylic box with much improved ventilation and access for cleaning within a fortnight. Dependant upon the response to this, I will also seek to move away from feeding black soldier flies to my mantids and will instead stick with fruit flies for younger instars and green bottle flies for older mantids. If you have any further feedback or advice, please do leave it below because it is heartbreaking to lose a mantis and as I have hopefully demonstrated here, I will do everything in my power to learn from my errors. Thank you for reading.

As ever, a link to the full-resolution album of images for those interested can be found here.

*Rest In Peace Stefanie: 23/04/2020 - 31/07/2020*


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## MantisGirl13 (Jul 31, 2020)

I can't see any pics.

- MantisGirl13


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## nzxmUyZNKEBoqN3e (Jul 31, 2020)

MantisGirl13 said:


> I can't see any pics.
> 
> - MantisGirl13


For Pete's sake, why does everything hate me. There is a link to the Imgur album at the bottom, some images may be out of kilter but that's the way the cookie crumbles. This has also been posted verbatim on the r/mantids subreddit if you want to see the images in their proper place.


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## MantisGirl13 (Jul 31, 2020)

So sorry for your loss. It looks like some sort of infection to me, I've had similar things happen in mantids before. 

- MantisGirl13


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## FabioFabiatic (Jul 31, 2020)

May she rest in peace.  

But it definitely looks like an infection with that black coloration. Try BBF or HF and a cleaner environment and update us if you notice fewer fatalities. Good luck and good job at inspecting the care you gave her in such a detailed and analytical way!!


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## Mantis Lady (Aug 1, 2020)

Sorry for your loss. It looks like she had an infection. Poor girl..


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## nzxmUyZNKEBoqN3e (Aug 3, 2020)

MantisGirl13 said:


> So sorry for your loss. It looks like some sort of infection to me, I've had similar things happen in mantids before.
> 
> - MantisGirl13






FabioFabiatic said:


> May she rest in peace.
> 
> But it definitely looks like an infection with that black coloration. Try BBF or HF and a cleaner environment and update us if you notice fewer fatalities. Good luck and good job at inspecting the care you gave her in such a detailed and analytical way!!






Little Mantis said:


> Sorry for your loss. It looks like she had an infection. Poor girl..


Thank you all for your support - it was hard to lose her for sure, but the best way to honour her is to learn from my mistakes.


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## Curiosity (Aug 4, 2020)

Yuck. I admire your nerve. . . I kind of want to make a point of dissecting my mantises after they die, so I can learn what they are supposed to look like inwardly in the case of age deaths or young accident victims, maybe even figure out what causes some of these mantis diseases and find cure, but once I get to know them, it's just not possible. 

This seems like a really morbid topic to say congratulations on, but that was meant as a compliment. You're clearly tougher than I am.


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