Pseudotracheal tubes, larval head, and mycophagy in Sepedophilus (Coleoptera : Staphylinidae : Tachyporinae)

Newton (in: Wheeler, Q.; Blackwell, M. (eds), Fungus-insect Relationships: Perspectives ill Ecology anti Evolution. New York: Columbia University Pres s, pp. 302-353, 1984) characterized five types of Sepedophilus larvae based on head structures and the external and internal features of the head of l arvae of Sepedophilus type C are described in detail herein. A functional i nterpretation of structures involved with feeding is made on the basis of m orphological and behavioural observations. Types C and D larvae possess tub e-like epipharyngeal structures resembling dipteran labial pseudotrachea, w hich may play an important role in a specialized liquid-feeding process. Ba sed on a preliminary analysis of head characters delimited by Newton (1984) it is shown that mycophagy has evolved once from a predatory ancestor, alt hough some Sepedophilus groups may have mixed feeding strategies. The epiph aryngeal tubes are demonstrated to be unique to mycophagous Sepedophilus in Coleoptera whereas the overall head structure is very similar to mycophago us larvae in the family Sphindidae.