Crawlers of the Scale Insect Mesophthirus (Homoptera: Xylococcidae) on Feathers in Burmese Amber—Wind Transport or Phoresy on Dinosaurs?

Mesophthirus engeli (Mesophthiridae incerti ordinis), described as a feather-feeding parasite of dinosaurs, has recently been reinterpreted as an early instar nymph (crawler) of a primitive scale insect. Mesophthirus has no specific similarities to bird lice, although life on feathers should modify parasites in a similar way. Based on re-examination of photographs of the type specimens of M. engeli, the subfamily Mesophthirinae stat. nov. is assigned to the archaic extant family Xylococcidae s.l. (recorded since the Hauterivian), next to the extant subfamilies Xylococcinae and Stigmacoccinae. Xylococcid honeydew is an important food resource for birds and other arboreal vertebrates. Like their modern relatives, Mesophthirinae lived under the bark of trees and produced copious honeydew. Early birds and their precursors, small feathered dinosaurs, may well have fed on honeydew and the mesophthirines themselves. Scale insect crawlers are adapted to wind transport and phoresy on insects and vertebrates, so finding Mesophthirus on feathers is expected.

Reply by Gao et al (2022) to paper see; https://link.springer.com/article/10.1134/S0031030122030054 or https://phthiraptera.myspecies.info/node/95673