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Quote Originally Posted by fish4all View Post
What temperature do you keep you colonies Jeff? And how many adult runners or Dubia would I need to have approximately 400-500 nymphs a month to feed to my frogs? Feeding supplemented with flies, wood lice and other stuff. I have tried to calculate this and have come up with 25 female Dubia and 20 female runners with extras from these numbers if they are breeding properly.
You calculations are correct. As unkempt said, you can expect about 20 nymphs per month from each adult female dubia and closer to 25-30 per month per female lateralis. These are pretty conservative values, and in optimal conditions you may see slightly more productivity (especially from the lats).

The flaw to this calculation and biggest issue for most new roach keepers is not accounting for nymphs that need to be fed and for nymphs that need to be held back to reach adulthood in order to replace current breeders. Thankfully, females will live and reproduce for many months after reaching maturity...upwards to a year or more. But maturity can take several months for either species... and factoring in "feeder size nymphs" is also important. For example, while you may produce 500 nymphs monthly from 25 females, they will all be newborn nymphs that you may only be able to feed a limited amount of herps until they gain some size. I would personally wait a couple of months AFTER you have your adult females so that a nice mix of nymphs is available as replacements to the colony and as feeders. You can never have too many roaches, and having too large a colony is always better than having too few and having to backtrack. I always shot for 1.5x-2x the recommended females when starting my colonies to err in the side of caution.

Cockroaches will thermoregulate much like a reptile or amphibian as unkempt suggested - I personally keep my heat tape under the entire bin and allow for an upwards gradient with egg flats. The roaches will travel toward the bottom for warmth and to the top to cool down. This is probably the most practical heating method for a large quantity of roaches in a single bin as you can completely pack the bin with egg flats. More egg flats = more surface area. More surface area means larger population per bin. The added surface area s particularly important for species who rather dislike crowding (i.e. Eublaberus sp.)

I have all of my bins set so that the inside bottom surface of the bin reads ~90. This is true for most of my feeder species, B. dubia and the lateralis included. Insect's function purely on enzyme kinetics driven by the environment....warmer temps mean faster growth to a certain point, but too much heat can have adverse effects. Given their natural range, I would imagine B. dubia would have an optimal temperature range of about 85-90 degrees F... but this is purely speculation from average temperatures in the neotropics where they reside in nature.