What are the most typical leaf mines of Nepticulidae? Identified diagnostic characters and their detection frequency

This study identifies major diagnostic morphological and some biological characters of leaf mines of Nepticulidae and provides a pictorial guide to the morphological characters with detection frequencies for each character. Drawing on detection frequencies, it establishes that the most typical leaf mine of Nepticulidae belongs to one of the two morphological types of (1) serpentine, gradually slightly widening and (2) serpentine, strongly widening, and that it can be characterised by black or brownish black frass accumulated in a solid line or band with wide clear margins of the gallery. Such a typical leaf mine is sinuous or contorted and, as a rule, found on Rosaceae or Betulaceae; the feeding larva is yellow.