Fertilised ootheca

[Twogglettz]

Is there any way to tell for certain if ootheca are fertilised? I got a ghost mantis a couple of weeks ago and was told she was definitely pregnant.

She laid an egg sack two days ago, and I've just taken it out and put it in a new enclosure, but seeing as there is only one, I'm a little worried it might not hatch. I thought her species had multiple ootheca.

Cheers for the help.

 

[Ranitomeya]

Mantises do not get pregnant as that implies having a developing embryo or fetus inside their body. The proper term for a  mantis that is full of eggs is gravid. Being gravid does not mean they have fertile eggs since fertile mantis eggs do not exist until they are on their way out of the body. After mating, sperm is stored in the spermatheca, an organ that is connected to the oviduct. The eggs pass by the spermatheca and are fertilized on their way down the oviduct to the ovipositor. Many insects store sperm--ant queens and queen bees store sperm from their nuptial flight for around ten years.

There is most likely more than just one egg. Most mantises lay multiple eggs at a time inside a foamy construct called an ootheca. The ootheca is a protective casing for the eggs inside and it helps keep them from drying out as easily and protects the eggs from extreme temperatures to a limited extent.

 

[CosbyArt]

@Twogglettz Sorry but with a Ghost (Phyllocrania paradoxa) ooth there is no way to tell if it is fertilized or not. That is at least until it hatches or is long past the time that the ooth should have hatched.

One of the very few mantid species that can be determined if a ooth is fertilized is the Wandering Violin mantis (Gongylus gongylodes). By using a candling technique the nymphs developing inside it can be seen; however, even then the eggs will need to be well underway in development to tell.

 

[Twogglettz]

@Ranitomeya, thank you for the information, but I think you misunderstood the question. My mantis had a single oothicae after being in an enclosure with males. I know female mantises have oothicas without breeding, and this is the problem: Does my oothicae have babies on it? How can zi tell?'

@CosbyArt Would a ghost mantis laying a single oothecae be more of an indicator to her having an unfertilised sac? I have Googled so many times about ghost mantises and ootheca numbers, but I can't find anything other than "they can have 12+". i know that they can lay an egg sac without fertilisation, so thaf's what I'm most worried about. 

 

[CosbyArt]

@Twogglettz No it doesn't help in knowing if it is fertilized or not. There is no way to be know if a Ghost ooth is fertile by any means, short of destroying the eggs to see. All female mantids will lay multiple ooths if they have mated or not over the course of their adult life (they lay ooths one at a time usually a week or so apart).

 

[Ranitomeya]

Ah, from what your original post said, it seemed like you obtained a mantis and was told it was "pregnant." You had not mentioned housing it with a male.

I've been able to candle Phyllocrania oothecae and see whether or not eggs are developing by looking for the developing eyes. You cannot tell immediately and have to wait a few weeks before you can see anything.

She will only lay one ootheca at a time and fill it with all the mature eggs she's produced since maturing or her last ootheca. My experience is that they'll lay about one ootheca every week or every other week depending on feeding and temperature. I've gotten as many as thirty nymphs per ootheca and as few as two. The number of eggs varies depending on how well fed they are kept and how old the females are. They tend to produce fewer and fewer eggs as they grow older.

Fertility will also decrease over time, so the number of eggs will not always match the number of hatchlings. Either the females cease to be capable of producing viable eggs, run out of stored sperm, they lose the ability to keep sperm viable, or the sperm they've stored loses its viability over time. I have had older females mated with fresh males produce infertile oothecae, so I'm assuming it's that they lose the ability to keep stored sperm viable or they are no longer capable of producing viable eggs--the same females had laid oothecae that produced 20-30 nymphs during the first couple of month of their adult lives.

 

[Ocelotbren]

@Ranitomeya I just wanted to say that your posts went into further detail than I have read thus far and were really informative, thanks!

@Twogglettz Hopefully your ghost is getting ready to lay another ooth soon now.