Inbreeding Effects on Mantids?

[River Dane]

I’ve been told that inbreeding is dangerous for mantids, others have said it’s only dangerous for some species, and other times people just say it doesn’t matter with insects.

So, to those with a decent amount of breeding experience, how do you feel about inbreeding? Have you noticed any differences in health between the offspring of unrelated vs related parents? And which species cannot or should not be inbred?

Just curious because this year I actually want to try breeding some mantids. 

 

[MantisGirl13]

Yeah, I have been wondering the same thing.....

Anyone have an answer?

- MantisGirl13

 

[Graceface]

I saw a video from Moonlight Mantids that mentioned this topic. He said inbreeding is okay to do once, or potentially twice. After that he said you start to see high initial die offs in nymphs. 

I'd love to hear more about this, too. Anyone have personal experience to share?

 

[ausar318]

I tried this with an independent line of Chinese, and the results were pretty much exactly like the video stated. I organized a bit of an experiment, but it is a very small experiment, with only one test group. So scientifically, the results are not accurate, but I think it does a decent job at quantifying the effects of inbreeding. My plan is to start over, with 3-4 test groups. (For the results I describe below, I don’t mention the control group, that is, the breeding of mantids that have a very low possibility of being related. For the control group, I kept only females, and harvested the breeding males from a friend’s house, which was about 10 miles away)

I hatched an ooth back in 2015 (when I first started in the hobby) and I separated a handful of nymphs to test this idea. The first generation parents, (X and Y) were perfectly healthy mantids from the same ooth (which was wild collected, so I assume the parents were not closely related).

When I crossed XY (2016), I got a second generation, and I didn’t notice anything out of the ordinary. Quite a few nymphs died, but no more than normal. I took a few nymphs from that hatch, (XY1 and XY2 - 2017), and bred them. The nymphs that I got from that ooth were also pretty normal, and I didn’t really notice anything different. About the same percentage died.

But I’m his last year, things didn’t go so well. I have much more experience now, so I should have had plenty of nymphs survive, but I did not. Of the three ooths that I hatched (Third generation of nymphs). Between the three ooths, I had about 500 hatch,  which is pretty normal. I kept them in the same conditions as the previous two generations, actually a bit better (because of the knowledge I had gained). Of the 500, I kept about 50. I fed them just the same as I fed the previous ones, on wild caught crickets, flies, and some ants (which my chinese mantids never struggled to catch and eat). Of the 50 L1s, only 6 made it to L2. There were only a couple incidents to cannibalism, but that is to be expected. So I had a 88% die off rate, which is Mitch higher than the 40-60% that I’ve experienced with my non-inbred generations. Unfortunately, none of them made it into adulthood, because they all died to either a mismolt or just randomly. 

Well, there’s my info on this topic. But like I said, I used a very small test group (of one), so my results are probably very skewed. I will probably test it again in the future, but it will probably be a while. I’ve got to get through college first. 

So to answer your question, @River Dane, my test seems to suggest that inbreeding will eventually result in genetic weakness, at least in Chinese mantids. Hopefully this provides a little clarification, but I hope others, especially long time breeders, will be able to shed some light on some other, exotic species. 

 

[Graceface]

Thanks @ausar318 Great info! Yes, your results sound similar to what Kevin said. He recommended that if you must inbreed, you should outbreed alternately to keep your genetic stock from deteriorating.

I have no experience with breeding mantids yet, but I assume it is a similar case with more exotic species as well. Considering the male and female Orchid Mantis mature at different rates, it would seem nature is trying to avoid inbreeding. 

 

[River Dane]

Thanks so much for your help @ausar318. And thanks so much for going into so much detail. So I take it inbreeding is fine for a generation or two, but outbreeding is necessary. Makes sense. Since I don’t know if my mantids are siblings, I’ll just go ahead and find them some mates when the time comes. 

Thanks again! 

 

[ausar318]

I think it’s probably the best idea. Especially if you are planning to sell/trade your nymphs. You don’t want to be distributing genetically weak mantids ?

I also want to do some additional trial, to maybe look at the effect of breeding “cousins” rather than siblings. There are just so many ways to take it. And I’m no geneticist, but I have the organizational abilities to keep track of a dozen or so bloodlines ?

 

[agent A]

inbreeding causes short-term problems because you cause lethal recessives to be passed along, resulting in the weak nymphs. now, say we start with several hundred nymphs from a continual line of inbreeding. eventually, the 2 or 3% of nymphs free from such recessives will be more fit than their sibs and as long as one offers the precise conditions the line has been inadvertently selected to survive, they will function fine. waxworms and crickets bred for pet food show this, as do domesticated silkworms. the problem is, who has time and space to accomodate thousands of baby mantises to allow for enough recessive-free individuals to survive and establish a culture? if mantises took up less space and weren't carnivores, it might work out