A female specimen of the new longhorned beetle species Borneostyrax cristatus. Photo by Radim Gabriš. CC-BY 4.0.

Generally, insects are oviparous, which means that the females lay eggs, where the embryonic development occurs. On the other hand, ovoviviparous species retain their eggs in their genital tracts until the larvae are ready to hatch — a relatively rare phenomenon in insects and even rarer within beetles.

“We studied the diversity of the rarely collected wingless longhorned beetles from Borneo, which is one of the major biodiversity hotspots in the world,” said co-author Radim Gabriš. “The mountains of northern Borneo, in particular, host a large number of endemic organisms.”

The scientists focused on a group which nobody has studied in detail for more than 60 years. They found surprisingly high morphological diversity in this lineage, which resulted in the descriptions of three genera and four species that are new to science.

“During a dissection of female genitalia in specimens belonging to the one of the newly described genera, named Borneostyrax, we found out that two females contained large larvae inside their bodies,” said Gabriš. “This phenomenon have [sic] been known in a few lineages of the related leaf beetles, but this is the first case for the longhorned beetles.”

Read more at:

– Review of Dolichostyrax Aurivillius (Cerambycidae, Lamiinae) in Borneo, with descriptions of three new genera and the first case of (ovo)viviparity in the long-horned beetles