G. portentosa ootheca
I get asked this question quite often, “Why is my female dropping her egg cases (ootheca)?”. A ootheca (egg case) is a segmented cluster of eggs a female roach produces and either lays (Oviparous) or holds and gives live birth (Viviparous).
Females will carry the ootheca protruding from their bursa, which is at their tail end until she either retracts it back into her uterus to incubate until the eggs hatch, or hide it somewhere until the eggs hatch, depending on the species. Egg laying species like B. lateralis will glue the ootheca in place securely with saliva when deposited. Generally 2 columns of eggs side by side form a cluster of 16-60 eggs (3/8″ – 1.5″). Ootheca’s can take anywhere from a couple of weeks to several months to hatch.
Roaches usually drop eggs cases (ootheca) if there is something wrong with their care or environment. Too wet, or too dry for to long, not fed in a long while (more than a week regularly), temps too cold/hot, etc. There could be a problem with fertility if it’s just one or two ootheca’s, but many, there is something else going on. Females may also drop their ootheca when dying.
Disturbing your roaches to often may also stress the female. The ootheca is gently held in the bursa and could easily fall off when the roach is handled roughly, like shaking the egg flat she hides in, etc. Blatta lateralis female will often drop under-developed ootheca’s when disturbed. Another possibility may be to many males.
When breeding roaches for food for your pets, you should have two bins. One for your breeders and one for your feeders. more if you want to separate by size. By having a separate bin for your breeders, the only time you should disturb them is when feeding and watering.
So if you’re experiencing dropped ootheca’s, double-check your setup and routines! Most species don’t need much to breed or keep as pets. A few places to hide, food, water source, warm temps if breeding, room temps if keeping as a pet and some humidity and your good to go.
