A 1-2 gallon container will work for a starter colony, but as they start breeding you'll want to move them to a larger bin or tank, something 5-10 gallons large. Larger species like P.saussurei will obviously need more room than smaller ones like aegyptiaca because of their much larger size. The development time for this genus is quite long, so it'll take colonies a while to outgrow whatever enclosure you put them in.
The substrate should be at least 2-3 inches deep, and should consist of coconut fiber or a similar material, NO sand should be used in the substrate. While they may live in sandy habitats in the wild, the micro-habitats they live in aren't necessarily sandy, and a lot of available sands are simply too abrasive for these. On top of the substrate, there should be a layer of decaying hardwood leaves, as it is supposedly an important part of their diet.
The substrate also shouldn't be too chunky, as the smaller nymphs may have a difficult time getting around, (sifting the coconut fiber to remove large particles and long fibers may be necessary). I've found this is particularly important for P.saussurei, I've had young nymphs of that species die off very quickly in enclosures where the substrate was too chunky and wasn't fine enough. P.aegyptiaca for example are less sensitive in that regard.
Most of the enclosure should be kept bone dry, with a quarter to a third of the substrate kept moist at all times. High ventilation levels are a must. Hides are not needed, they are strictly burrowers so the substrate gives them all the refuge they need.
Diet:
A staple diet of dog/cat/chick/fish feed and decaying hardwood leaves works best for this genus. Most fruits and veggies go untouched.
Temperature:
Polyphaga spp. will breed readily anywhere from 68-85F°, I personally prefer keeping mine in the middle of that range, 74-76F°.
Oothecae of some more temperate ranging species may need a mild winter diapause for their oothecae, 1-2 months kept in the low to mid 60s F° usually works fine.
Breeding/Life cycle:
Adult females usually live 1-3 years, even longer is not unheard of. Adult males usually live up to a year, which is still unusually long for adult male Corydiidae.
Breeding/Life cycle:
Adult females usually live 1-3 years, even longer is not unheard of. Adult males usually live up to a year, which is still unusually long for adult male Corydiidae.
The most popular P.saussurei strain currently in the hobby (and perhaps EU hobby P.obscura, if they even exist in culture) is a parthenogenetic one. This means all individuals are females and are capable of asexual reproduction.
Females lay oothecae that can vary greatly in size, and deposit them directly into the substrate. So long as one or two corners of the enclosure are kept moist, (preferably about a quarter of the substrate), then the ambient humidity should be high enough for ooths to hatch, even in the driest areas of the enclosure.
The oothecae take 6-8 months to hatch, with P.saussurei ooths taking the longest. Nymphs normally take just over a year to mature if kept warm and well fed, though if kept cool, they may take nearly two years to mature.
Species Notes:
Polyphaga aegyptiaca (Egyptian Sand Roach):
The first of the Polyphaga to enter culture, a hobby classic. All strains in culture are sexually reproductive and quite prolific.
Polyphaga obscura (Obscure Sand Roach):
The name obscura suits this species well, especially since most "obscura" strains in culture are merely mislabeled P.saussurei. A parthenogenetic line of true P.obscura MAY be in culture in Italy and perhaps other parts of Europe, though this has yet to be confirmed...
Polyphaga plancyi (Chinese Sand Roach):
This is probably the most colorful of the Polyphaga species, and hails from temperate China. Seems to like a little bit more humidity than the other Polyphaga spp., and their ooths appear to require a mild winter diapause for consistent hatching. Nymphs and adults however do not require a diapause, and nymphs typically mature within a year when kept warm. All stock in culture is sexually reproductive.
Polyphaga saussurei (Saussure's Giant Sand Roach):
The largest species in the genus, adult females sre great for handling. The most widespread stock of this species in the hobby is parthenogenetic, however the species is normally sexually reproductive, and one or two strains with males and females do exist in culture (but are very rare).
All life stages can be kept warm year round with success, however ooths will hatch must faster if you give them a diapause (only 2-4 months incubation total, instead of the usual 6-8 kept warm year round).
