Sudden Mantis Death Syndrome

[GreenBean]

It happened again tonight...I just had a very healthy-appearing adult female (UN-mated), who just molted into adulthood maybe 3 weeks ago, drop dead on me within a couple hours. Clinical exam: all appendages intact, no necrotic tissues (aka: "black death") obvious anywhere, full abdomen (not starving) but not on the verge of exploding (you know that look), has been isolated from other mantids its whole adult life, let out to "play" regularly, housing had stable ambient temps, was humid enough and regularly misted, diet consisted mostly of gut-loaded crickets with the occasional moth or bloodworm thrown in...

SO, what is it? This is the third time this season this has happened to a bug that was active and healthy only to meet its demise a couple hours later. They end up on their back, not moving. With old age, they tend to deteriorate gradually over days...they quit eating, show signs of neuronal degeneration, get "spots" and tattered wings... But this...no warning at all! She was found in the wild, Oregon. Not sure of species.

Any ideas at all?

 

[Rick]

Found in the wild as an adult? If so I would say old age. Tattered wings and spots are a classic sign of an old mantis. If that isn't it take a look at your housing conditions closely. I found many years ago that frequent handling was bad for them. Not saying that is what you're doing, but some people think mantids should be played with.

 

[Krissim Klaw]

My first thought for an otherwise healthy, active, well eating and drinking young adult mantis would be could she have gotten some bad food. You mention the occasional moth if you catch those there is always the chance it could have gotten some pesticide or something on it. I have also heard members mention that pet-store purchased crickets that are often kept in such crappy conditions can sometimes cause problems. While there is some debate about whether bad batches of crickets are really responsible for said mantises deaths it might be worthwhile to look into getting your crickets from healthier stock. I know a lot of the members on this site prefer to order theirs from certain sites.

Another thing I would ask is are your mantises getting water regularly and if so what is the source; as in are you using tap water, which often has unwanted chemicals?

Finally, a wild caught mantis that is only three weeks into its final molt sounds like she might be rather late in the season. I know Rick mention the couple times he has seen parasites that emerge from wild caught mantises they always seemed behind the growth rate of the majority of other wild mantises. I would have thought though the parasite would have emerged around the time or shorty after the deaths. Still late bloomers in the wild might in general be a sign that there could be a something wrong and thus a reason why the wild mantises are reaching adulthood so late in the season.

 

[GreenBean]

Found in the wild as an adult? If so I would say old age. Tattered wings and spots are a classic sign of an old mantis.

Yeah, found in the wild, but I saw her go through her final molt just 3 weeks ago, so I know she wasn't very old at all.

If that isn't it take a look at your housing conditions closely. I found many years ago that frequent handling was bad for them. Not saying that is what you're doing, but some people think mantids should be played with.

You bring up an interesting point. I have often wondered just how good it is to handle mantids. There are certain bugs (ie., butterflies vs. the oil on our skin, which is very harmful to them) where it is well documented that frequent handling shortens their lifespan. This might be worth an experiment. As for this one, though, I handled her very little, only as necessary. HOWEVER....as I did find her in the wild having just finished her final molt, I wonder if I handled her too soon during that fragile after-molt period and THat somehow shortened her lifespan. But again....we're talking about a sudden death weeks later. It wasn't like she was "never right" after her molt.

 

[GreenBean]

My first thought for an otherwise healthy, active, well eating and drinking young adult mantis would be could she have gotten some bad food. You mention the occasional moth if you catch those there is always the chance it could have gotten some pesticide or something on it. I have also heard members mention that pet-store purchased crickets that are often kept in such crappy conditions can sometimes cause problems. While there is some debate about whether bad batches of crickets are really responsible for said mantises deaths it might be worthwhile to look into getting your crickets from healthier stock. I know a lot of the members on this site prefer to order theirs from certain sites.

Yes, I have heard this before and I do wonder if it could be the case. Last year I mail-ordered from Flukker's and I didn't have such problems. I think I just might do that again. It's cheaper, too!!

Another thing I would ask is are your mantises getting water regularly and if so what is the source; as in are you using tap water, which often has unwanted chemicals?

Yes, I am very careful to mist and to keep the surrounding environment humid (I have a gauge to check this). And the tap water we have is from a well, no added chemicals, out here in the Cascade Mountains.

Finally, a wild caught mantis that is only three weeks into its final molt sounds like she might be rather late in the season. I know Rick mention the couple times he has seen parasites that emerge from wild caught mantises they always seemed behind the growth rate of the majority of other wild mantises. I would have thought though the parasite would have emerged around the time or shorty after the deaths. Still late bloomers in the wild might in general be a sign that there could be a something wrong and thus a reason why the wild mantises are reaching adulthood so late in the season.

This is an interesting point and one I pondered myself. I was quite stunned to find her, especially after I was sure the weather no longer supported life for mantids this season. However, I still have two youngsters (REALLY late bloomers!) I found earlier in the season--before the colder temperatures set in. They are still doing fine...awaiting any day for one to reach adulthood and the other to reach subadult instar. Indeed, this seems very unusual to me to have these 2 wild-caught mantids which obviously hatched very late this year.

 

[Rick]

She may just have been slow to develop. She may still be just as old as most of the others outside. Normally a food illness takes a little time to kill them. Take a look at your conditions if you don't feel it is old age.

 

[sporeworld]

When I "handle" my mantids, I really mean I let them walk on my hand, then let them walk off it again. I don't think I've ever pet or touched a mantis anywhere else (I'd probably get thumped!).

But I can imagine all sorts of toxic materials in my office that they could walk on and then injest durung cleaning - which is why I don't let them wander out of my sight (that, and I'd never find them). I had a male ghost fly away from me the other day (man, they can fly) and I was scared he would land on the cleaning supplies (he didn't). Might be worth a look around to see if you have any exposed chemicals, soaps, that sort of thing....

 

[GreenBean]

When I "handle" my mantids, I really mean I let them walk on my hand, then let them walk off it again. I don't think I've ever pet or touched a mantis anywhere else (I'd probably get thumped!).

But I can imagine all sorts of toxic materials in my office that they could walk on and then injest durung cleaning - which is why I don't let them wander out of my sight (that, and I'd never find them). I had a male ghost fly away from me the other day (man, they can fly) and I was scared he would land on the cleaning supplies (he didn't). Might be worth a look around to see if you have any exposed chemicals, soaps, that sort of thing....

This is a good point and I am aware of mantids' sensitivity to toxins. Mine are never exposed to such things. They live in a very healthy environment (as do I--organic/nontoxic). They live in their own shed (in their cages) that I have created for them surrounded by plants, flying insects, an aquarium of local flora and fauna, that's it. Plus, we live in a rural area of the Cascade Mountain range. Yep, this environment is about as good as it gets, but a good point nonetheless.