Sexing Dubia and Development Cycles

Blaptica dubia, the Dubia roach, are a sexually dimorphic species of Tropical cockroach.  This means that the have different physical characteristics between the 2 sexes. 

Sexing the Roaches 

The the adult stage of the Dubia roach have predominant features that separate the too. In the image below you can get a visual sense of these differences.

The males have wings the run the length of their bodies and extend beyond their abdomen. They cannot fly, but can help direct their fall from short distances. They will flutter their wings rapidly if held by them alone. 

The females do not have full developed fore-wings, they are short and often referred to as tegmina. 

To tell tell the difference in the sex of a Dubia Roach before sexual maturity requires a bit more of a closer look. Generally female nymphs have a wider base of its abdomen, and a single piece of its chitin (shell) at the base. 

Dubia Roach Lifecycle

• Mating occurs when the male deposits a sperm packet in the female. This sperm packet inhibits the female from further mating.
• Females then lay an ootheca (egg case with segmented parts), they then pull this sack back into themselves to incubate ovovivoparitally (internally and giving live birth).
• Gestation is about one month (28 days).
• Nymphs hatch inside the female. Between 20 and 40 live young, each about 2-3 mm long, are produced in each ootheca  .
• Nymphs mature in about 4–6 months depending on temperature and food supply.
• Nymphs undergo 7 instars, its pronotum (shell) grows about 25% between molts, before reaching adulthood.
• Adults live 1–2 years.

Dubia young and shortly after a molt they are bright white, fleshy and soft. After a few hours of emerging as their chitin hardens they will darken into the black and brown they are known for having.