Abstract
Abstract. Rhopalosomatidae are an unusual family of wasps (Hymenoptera: Aculeata) comprising less than 100 species found in the tropics and subtropics of all continents except Europe and Antarctica. Whereas some species resemble nocturnal Ichneumonidae, others might be mistaken for spider wasps or different groups of brachypterous Hymenoptera. Despite their varied morphology, all members of the family supposedly develop as larval ectoparasitoids of crickets (Orthoptera: Grylloidea). Here, we report on the first record of a fossil rhopalosomatid larva which was discovered in mid-Cretaceous amber from northern Myanmar (Burma). The larva is attached to the lateral side of a cricket between the metafemur and the abdomen, impacting the natural position of the hind leg, exactly as documented for modern species. Additionally, the larval gestalt is strikingly similar to those of extant forms. These observations imply that this behavioral specialization, e.g., host association and positioning on host, likely evolved in the stem of the family at least 100 million years ago.
Highlights
Rhopalosomatidae are a family of aculeate wasps that as larvae are ectoparasitoids of crickets and are distributed predominantly pantropically
We report on the first record of a fossil rhopalosomatid larva which was discovered in midCretaceous amber from northern Myanmar (Burma)
During recent surveys of fossil inclusions, an almost completely preserved cricket was discovered in Burmese amber; it has a late-instar rhopalosomatid larva attached to the lateral abdominal wall immediately behind the hind leg, resulting in the characteristically awkward protrusion of the leg obliquely away from the body
Summary
Rhopalosomatidae are a family of aculeate wasps that as larvae are ectoparasitoids of crickets and are distributed predominantly pantropically. During recent surveys of fossil inclusions, an almost completely preserved cricket was discovered in Burmese amber; it has a late-instar rhopalosomatid larva attached to the lateral abdominal wall immediately behind the hind leg, resulting in the characteristically awkward protrusion of the leg obliquely away from the body. This represents the first discovery of immature vespoid parasitoids from the Mesozoic and reveals a considerable constancy in rhopalosomatid biology over the last 100 million years
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
