Evidence from amber for the origins of termitophily

Summary

Fossil morphology is often used to infer the ecology of extinct species. In a recent report in Current Biology, Cai and colleagues [1] described an extinct rove beetle, Cretotrichopsenius burmiticus, from two specimens in mid-Cretaceous Burmese amber (∼99 million years old). Based on morphology and the taxonomic group to which the specimens belong, the authors proposed that Cretotrichopsenius was a termitophile — a socially parasitic symbiont of termite colonies. Moreover, the new taxon was claimed to represent the oldest "unequivocal" termitophile so far discovered, pushing back the known evolutionary history of termitophily by ∼80 million years, close to the origin of termite eusociality. Cretotrichopsenius is certainly an important discovery for understanding the evolutionary steps leading to this type of social insect symbiosis. However, we issue a caveat here concerning the authors' assertion that Cretotrichopsenius was truly termitophilous. Additionally, we question the authors' representation of a previously published, likely-termitophilous rove beetle in Burmese amber [2].