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

Newton (in: Wheeler, Q.; Blackwell, M. (eds), Fungus‐Insect Relationships: Perspectives in Ecology and Evolution . New York: Columbia University Press, pp. 302–353, 1984) characterized five types of Sepedophilus larvae based on head structures and the external and internal features of the head of larvae of Sepedophilus type C are described in detail herein. A functional interpretation of structures involved with feeding is made on the basis of morphological and behavioural observations. Types C and D larvae possess tube‐like epipharyngeal structures resembling dipteran labial pseudotrachea, which may play an important role in a specialized liquid‐feeding process. Based on a preliminary analysis of head characters delimited by Newton (1984) it is shown that mycophagy has evolved once from a predatory ancestor, although some Sepedophilus groups may have mixed feeding strategies. The epipharyngeal tubes are demonstrated to be unique to mycophagous Sepedophilus in Coleoptera whereas the overall head structure is very similar to mycophagous larvae in the family Sphindidae.