How do bat bugs reproduce differently from most other heteropterans?

Unlike most other heteropterans, which typically fertilize eggs as they pass through female ducts and lay them externally, bat bugs (family Polyctenidae) exhibit a unique reproductive process.1

In bat bugs, fertilization occurs within the female ovariole, where the eggs remain throughout their development. These eggs are shell-less and yolkless, and the developing embryo is nourished by the mother through a placenta-like structure formed from both parent and offspring tissues. Consequently, the young are born alive in an advanced stage of development, rather than hatching from eggs laid in the environment as is common among other members of the order Heteroptera.12