The complete life cycle of a Cretaceous beetle parasitoid

Life cycles of parasites, particularly those with complex life histories and developmental pathways, are rarely preserved as fossils in total.¹ The evidence is almost universally biased toward incomplete perspectives derived from a single sex or life stage.^2,3 Here, we report a piece of Cretaceous Burmese amber that contains 28 males, a larviform female, and two longipede larvae of the wedge-shaped beetle Paleoripiphorus, and its potential cockroach host. Collectively, this fossil represents the complete series of free-living stages (except of the last larval instar) for a 99-million-year-old parasitoid insect from Myanmar (Figure 1 and Supplemental Information). The wedge-shaped beetles (Ripiphoridae) are of special interest among parasitoids because of their obligatory, protelean development in larvae of cockroaches, beetles, bees and wasps.⁴.