Mantid Abdomen Explosion

[jooly]

Hello all! 

My name is Julie Anthony, and I am doing research on the natural history of the Giant Dead Leaf Mantis (Deroplatys dessicata). I was hoping for your help with my research! Unfortunately, Many of my adult females abdomens have been "exploding". Their abdomens will become large with eggs and their abdomens explode out the side and eventually kill them (photos below). I have also seen this with Chinese mantids and Ghost mantids in my experience. I've only seen this phenomenon happen in adult female mantids, never males. My question for you, is have you see this happen with your mantids? And if you have, what species was the mantid, what sex was the mantid, and what were you feeding them? 



I would love to cite your information in my paper. Please let me know if that is alright with you.

Thanks so much for your help!

Julie

 

[Salmonsaladsandwich]

Oh dear... I don't think that happens very often. Could it be a disease? Normally mantids know better than to eat until they explode.

 

[Krissim Klaw]

Unless you witnessed the rupture it is possible the mantis fell and ruptured her abdomen versus exploding from internal pressure alone. One of the reasons I like to not over-stuff my girls is it can put them at serious risk even in a minor fall.

I have only once had a female rupture an abdomen from internal pressure alone. She was a very old Euchomenella macrops. Toward the end of this species life I noticed the girls would often get paper thin at the seams between the section in their abdomens. The rest of their body seems to get especially weak around the joints in general.

I was already feeding this girl on the lighter side but shortly after a meal her right side at one of the segment seams ruptured and she lost a lot of blood. There was no fall in this case as I was present when the mantis started too ooze. I thought for sure she was going to be a goner but her blood started to clot on its own and I provided ample water so she could replenish the lost fluid. The injury didn't effect her at all once it clotted up and she went on to live a couple months more before finally succumbing to what appeared general old age. The only thing I did differently after was make sure to keep her meals especially light. Interestingly this isn't even a species you would assume would be at risk for ruptures because they don't get nearly as heavy as a lot of other species do.

 

[Sticky]

How much were you feeding them Jool? Some will over eat, others wont. Those that do over eat can rupture so it is up to us to judge how much they can eat safely before they get overfed.

 

[jooly]

I appreciate all of your responses. I thought that it was overeating at first as well, and in some cases I thought the females were still gravid but unable to oviposit. And I see what you're saying about them becoming too large and their abdomens tearing on the foliage or another external pressure. I was feeding them ample amounts of crickets, but after dissecting them it seems to be an internal issue. 

I found that these mantids had blockages in different parts of their gut systems. Some had blockages going from the foregut to the midgut while others had blockages from the hindgut to the excretory system. These blockages were consistently placed in coordination with where the abdomen ruptured. 

I've spoken with several colleagues about this phenomenon and they don't think overeating would be very likely since mantids in the wild are able to eat as much as they want. And several other insect zoos have seen this rupture in their mantids. Some have seen it in D. dessicata while others have seen it in Asian and Chinese mantids. Usually, the rupture only occurs in female mantids and only occurs late in life. All of the mantids whose abdomens ruptured under my care were females, but, comparatively, all of them were young adults. Less than five months old when the rupture occurred. D. dessicata are likely to live over a year as adult females, and I'm not sure why these gut blockages happened and my females died prematurely. Any thoughts? 

Also, what do you feed your mantids generally? Crickets? Cockroaches? 

 

[guapoalto049]

Do your enclosures have lots of smooth surfaces (glass, acrylic, etc.)? Also, what height are the terraria?

 

[jooly]

Do your enclosures have lots of smooth surfaces (glass, acrylic, etc.)? Also, what height are the terraria?

The terraria are just small kritter keepers. There are some sticks for the mantids to crawl on. These particular mantids have a very thin cutitcle, so I think you guys are right that the abdomen's may have been torn on foliage rather than an internal issue.

Fortunately (and unfortunately) from this experience, it prompted me to dissect the mantids which led me to a separate issue with internal gut blockages. If anyone else has dissected mantids and seen these gut blockages, I would love to chat with you! 

 

[Rick]

I have never seen that happen unless the mantis was heavily egg bound and has fallen onto a hard surface. 

If wonder if the diet has anything to do with the blockages you found. 

How lucky are you to study and work with mantids!

 

[hibiscusmile]

What again is their diet? One of the things I have found, is overfeeding and no room to excercise. 3 Bluebottle flies are plenty for a days feeding. They need water too. They need room to move around. Those who keep them in 32 oz cups are how do I say it? Inhumane treatment. They need room to move around on surface they can grab and such. All my mantis, male or female, have glued flowers and sticks in their houses and never live in 32 oz cups except for needed when molting and want to be alone.

 

[Krissim Klaw]

Are you sure the blockages where actual blockages? Were the mantises passing waste without issue beforehand? Any signs of vomiting? The only times I've dealt with blockages in mantises it was very obvious from the outside there was a blockage because waste stopped passing and the mantises would spit back up after attempting to eat.

 

[jooly]

I was feeding the adult mantids three times a week. They were getting multiple crickets, 4-5, at each feeding. As adults the mantids were only eating crickets and no other food source. Online, I read that you can feed your mantids as much as they can eat since that's they would do in the wild. Unfortunately, I've found out this is not the case and they were probably overweight and prone to injury.

The mantids were kept individually in small kritter keepers as adults. They had sticks "criss-crossing" their cage for them to crawl up to the roof of the cage. From my observations, D. dessicata are a very slow-moving mantid by nature. Even when I put them in large cage for mating or experiments they pretty much stayed on one side of the cage the whole time. I'm not really sure how to exercise mantids...any thoughts?

3 Bluebottle flies are plenty for a days feeding. 

For this statement, what species of mantid are you feeding bluebottle flies? And what stage of life? Adult? The adult D. dessicata are quite large and do not tend to eat flies or anything smaller than a large cricket. 

Are you sure the blockages where actual blockages? Were the mantises passing waste without issue beforehand? Any signs of vomiting? The only times I've dealt with blockages in mantises it was very obvious from the outside there was a blockage because waste stopped passing and the mantises would spit back up after attempting to eat.

And for this statement, I'm not sure if there were signs of vomiting. But after dissection, I found hard blockages in the dead mantids abdomens that were causing strain on the internal organs - they were larger and more swollen than normal. Did your mantids ever vomit something back up, or simply spit out food that had not been digested?

 

[Krissim Klaw]

And for this statement, I'm not sure if there were signs of vomiting. But after dissection, I found hard blockages in the dead mantids abdomens that were causing strain on the internal organs - they were larger and more swollen than normal. Did your mantids ever vomit something back up, or simply spit out food that had not been digested?

Usually vomit is hard to miss if it has been going on for any length of time. It often smells downright vile and the brown smears across the cage walls/ceiling tend to be hard to miss. I never had a mantis with a blockage spit back up any of the blockage. The food gets cut off, starts to sour since it can't fully pass through and they start getting sick. Meanwhile on the opposite end waste production slowly trickles off as what is left on the opposite end of the blockage empties out and nothing new enters. I haven't run across this problem more than a couple of times, but interestingly every time I have it has been after a shedding. The mantis will have been fine prior but when I start up food once it has fully hardened things just don't work right. I can only assume something went wrong internally during the shedding process.

 

[jooly]

I can only assume something went wrong internally during the shedding process.

I have seen the brown smears on the cage walls/ceilings. I didn't realize that this was vomit. And I know what smell you're talking about. I always kinda assumed the smell was dead crickets or something else. I've seen the vomiting in a few month old adult female, but I'm not sure if I saw the vomiting right after a molt though. That's interesting that you found the vomit right after a molt. I hadn't consider that there may have been internal issues when the mantis shed that could have caused these issues. That's very interesting and clever that you thought of that. 

Also, I noticed that whenever the mantid's abdomen ripped there was this black, gummy tar that was located at the site of the rupture. Is this gummy tar the product of hemolymph coming into contact with oxygen?