Life habits and evolutionary biology of new two-winged long-proboscid scorpionflies from mid-Cretaceous Myanmar amber

• Published in: Nature communications 2019-03, Vol.10 (1), p.1235-1235, Article 1235
• Main Authors: Lin, Xiaodan, Labandeira, Conrad C., Shih, Chungkun, Hotton, Carol L., Ren, Dong
• Format: Article
• Language: English
• Subjects: 147/135; 147/28; 631/158/2462; 631/181/2480; 631/181/414; 631/601/1466; 96/63; Amber; Animals; Biological Evolution; Cretaceous; Cycadopsida; Female; Fluidization; Fluidizing; Food; Fossils - anatomy & histology; Genitalia; Herbivory - physiology; Humanities and Social Sciences; Hypopharynx; Inflow; Insecta - anatomy & histology; Insecta - physiology; Insects; Male; Mecoptera; Mesozoic; Mouthparts; multidisciplinary; Myanmar; Organs; Phylogeny; Plant reproduction; Pollen; Pollination; Science; Science (multidisciplinary); Sex Characteristics; Swarms
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-09236-4

Long-proboscid scorpionflies are enigmatic, mid-Mesozoic insects associated with gymnosperm pollination. One major lineage, Aneuretopsychina, consists of four families plus two haustellate clades, Diptera and Siphonaptera. One clade, Pseudopolycentropodidae, from mid-Cretaceous Myanmar amber, contains Parapolycentropus . Here, we newly establish Dualula , assigned to Dualulidae, constituting the fifth lineage. Parapolycentropus and Dualula lineages are small, two-winged, with unique siphonate mouthparts for imbibing pollination drops. A cibarial pump provides siphonal food inflow; in Dualula , the siphon base surrounds a hypopharynx housing a small, valved pump constricted to a narrow salivary duct supplying outgoing enzymes for food fluidization. Indirect evidence links long-proboscid mouthpart structure with contemporaneous tubulate ovulate organs. Direct evidence of gymnospermous Cycadopites pollen is associated with one Parapolycentropus specimen. Parapolycentropus and Dualula exhibit hind-wing reduction that would precede haltere formation, likely caused by Ultrabithorax . Distinctive, male Aneuretopsychina genitalia are evident from specimens in copulo, supplemented by mixed-sex individuals of likely male mating swarms. Long-proboscid scorpionflies were associated with mid-Mesozoic gymnosperm pollination. Here, Lin et al. establish a new family of long-proboscid scorpionflies from Myanmar amber, elucidate evolutionary mechanisms of hind-wing reduction, and detail feeding and reproductive habits of these insects.