Humidity vs Ventilation conflict

[BoxOfFrogs]

Hello and good evening from the UK

I'm just 4 weeks in to my mantis ownership (an L3 Orchid Mantis) and am avidly reading and watching as much as I can about them. One of the difficulties I'm having is maintaining the humidity in my enclosure.

Firstly, there are different recommendations from different 'experts' - mostly I read that 60-80% is ideal, but I think that is quite a generic figure for any mantis: I have seen a suggestion that orchid mantises need it lower. But, they need it high when young to aid molting … or do they!?! Anyway, I imagine there is some scope for variation.

I have a small temp and humidity sensor mounted inside the enclosure quite low down - I chose that location to ensure the temp was high enough near the heat mat area knowing it would become closer to room temp as distance from it increased (i.e. higher up). This means a gradient for the mantis.

However, the humidity down there generally reads 20-30% unless I mist the enclosure - the reading then jumps to something approaching 80% but only for a short period. The top of the enclosure (which is glass-sided and bottomed) is mesh, which allows for the ventilation that is always stressed as vital. To try to help, I have a small plastic water bowl with sponge in, topped up with water. This is placed on the bottom of the enclosure over the heat mat - the hope being that evaporation will aid the humidity. But this has been in place for a while and hasn't increased the reading from its steady 20-30%.

Our house thermostat is usually set for 21C when we're here, 18C when not and over night (approx. 70F and 64.5F respectively). The thermostat in the enclosure reads around 23-34C (approx. 63-75F). When simply hanging around, my mantis spends a long time hanging from the mesh at the top. She does roam around occasionally but definitely likes it high up. I imagine the temp here will be close to room temp due to the mesh so a bit lower than most suggestions. To counter that however, one of the staff at the pet shop I bought everything from said she doesn't even use a heat mat for her mantises and has never had any problems! 

Now then, in these conditions my mantis successfully molted 2 weeks ago so things must be reasonable. Should I just chill out?

Thanks to all responses to previous messages, much appreciated. Have fun.

Keith.

 

[BoxOfFrogs]

Sorry, a bit more info that may be relevant.

I bought the items as advised by the pet shop guy - he has been keeping and breeding mantises for 12 years - and I started with coconut shell substrate (the compressed kind that expands when you add water), a branch of sterilised driftwood, and heat mat. Within 5 days I had mould blooming on several sections of the branch! To avoid this I changed to using paper tissue on the base of the enclosure, the bowl of water/sponge and a 'tree' sculpted from electric cable still in its outer insulation. No mould since.  

 

[ohaple]

I don't have definite answers for you, but some suggestions.

1. Move the heat mat to the back wall if possible. It will help give the mantis more heat and reduce the evaporation spikes you have dealt with.
   
2. Add a substrate that holds water well. Make it deeper than you think you should. Get the substrate damp and it will release humidity better over time.
   
3. To cope with the mold from step 2, get some springtails. Most reptile stores in my area carry them for $10, and online retailers also sell them. They keep things smelling fresh and keep mold down. They do an incredible job. We havent changed substrate since setting it up, and we have no mold and it smells like a fresh forest.
   
4. Consider adding some isopods for additional waste control and supplemental food for the mantis.
   
5. Humidify the room AND mist the enclosure. In Colorado, we struggled with the same thing you have. 20% humidity, mist, 90% humidity, a couple hours later, 20% humidity again. We have worked on solving this in two ways. First, we installed a whole house humidifier. You could also use a room humidifier. We added it for our own health, but it makes the humidity easier for the mantises too since it slows down the evaporation. Second, we have gotten careful about how we mist. We try to mist so that the substrate gets damp, but not wet. When we mist harder surfaces we find it evaporates much more quickly. Together we now see humidity fluctuate 50%-70% rather than 20%-90%, which I am sure is better for our mantises.
   
6. Some species are easier than others. I don't know much about orchids, but I notice a major difference between our mantises. It feels like we would have to do something seriously wrong to cause a mismolt of our ghosts or h. majuscula, while our peacock and short-lived diabolica seem more temperamental.
   

You are on the right track, just keep dialing in your routine and I am sure they will be fine.

 

[BoxOfFrogs]

Thank you so much ohaple

I would prefer a natural substrate for both aesthetics and moisture control but was concerned about the mould. I have read about springtails etc. and have one outstanding question - how are the numbers of springtails controlled? Do they not breed to excess? Or do they simply 'expand to fill the available resources'? 

 

[MantisGirl13]

For my orchids, I have paper towel substrate and a pretty wide screen lid, so humidity is hard to keep up, but the ventilation is great! I spray them once or twice a day and the orchids are thriving at 50-60% humidity. I have found that they are pretty flexible and adapt well to different humidities. I would doas ohaple says and put down moisture retaining substrate and keep it moist.

- MantisGirl13

 

[BoxOfFrogs]

Thanks MantisGirl13 - I covered half of the mesh lid with foil and the humidity stays close to 50% (better than the 20-30), with an easy jump to 80% after a misting. 

 

[MantisGirl13]

Thanks MantisGirl13 - I covered half of the mesh lid with foil and the humidity stays close to 50% (better than the 20-30), with an easy jump to 80% after a misting. 

Perfect! Good job! 

- MantisGirl13

 

[ohaple]

Thank you so much ohaple

I would prefer a natural substrate for both aesthetics and moisture control but was concerned about the mould. I have read about springtails etc. and have one outstanding question - how are the numbers of springtails controlled? Do they not breed to excess? Or do they simply 'expand to fill the available resources'? 

To answer re springtails. Their numbers fluctuate with the food available (mold). When mold spikes, they are all over, then they level out to a moderate level. I have not heard of them infesting a habitat uncontrolled. Just make sure you aren't adding things that create excess mold.

 

[BoxOfFrogs]

To answer re springtails. Their numbers fluctuate with the food available (mold). When mold spikes, they are all over, then they level out to a moderate level. I have not heard of them infesting a habitat uncontrolled. Just make sure you aren't adding things that create excess mold.

Thanks ohaple