So a single fly a day until I can catch more good
Humidity in winter is likely a problem; however, with only a single fruit fly per mantis for a feeding that is the main problem.
That itself is more than enough reason for them to fall over dead from hunger (let along successfully molt, they don't have the energy to pull themselves from the exoskeleton).
If they are kept together I imagine some will survive due to cannibalism, but if individually housed they are all too weak. Most of my L1 nymphs tend to eat 2-3 fruit flies per day each, with the L2 stage eating six or more, and at L3 and above they are moved to other feeders (depending on the species).
And is there any manipulation that can be done to help fallen mantids? I'm assuming not but would love to know.
Some keepers have some luck if they catch the mantid right after the fall; however, if the nymph sits at all it will dry out and no help will be effective.
The most successful method is to re-anchor the mantis on the lid and let it finish molting. Sometimes the old exoskeleton can also be pulled free from legs if it is nearly done molting, using a toothpick or such, but any excessive force simply distorts/stretches the mantids new exoskeleton like taffy but it will not return/unstretch to normal. So use care to apply the smallest of strength/pressure - and any hand/finger pulling should be avoided.
Other times sharp scissors or such will be needed to trim the old exoskeleton to free the nymph. In cases if it is trapped and unable to be freed, then amputation of affected limbs may need to be done.
Like all things a decision must be made quickly and carried out for any chance to help. Just remember a nymph can regrow and repair problem limbs, antennas, etc. - it is better for a chance for the nymph to survive than to die during a molt.
