Table 2.

Forewing characters used by Shcherbakov⁹ to define the families and subfamilies.

Character	Liadopsyllidae	Malmopsyllidae	Malmopsyllinae	Miralinae	Modern Psylloidea (NHMB data)	Polarity, apomorphic state
Costal space	Elongate, usually ribbon-shaped	Widening proximally or distally	Not widening distally	Widening distally	Variable, sometimes within a genus	Unknown
Pterostigma	Usually present, but often poorly developed	Distinct, dark	Not mentioned	Not mentioned	Variable, sometimes within a genus	Unknown
R + M + Cu [R + M + CuA] bifurcation	at < 1/5 wing length	at > 1/4 wing length	at 1/4–1/3 wing length	before wing midlength	variable, sometimes within a genus	unknown
R bifurcation	At < 1/3 wing Length	At > 0.4 wing length	At 0.4–0.5 wing length	Beyond wing midlength	Variable, often within a genus	Unknown
M	Forked	Not mentioned	Forked	Unforked	Usually unforked	Unforked
M + Cu [M + CuA] bifurcation	Not mentioned	Not mentioned	At 0.35–0.5 wing length	Beyond wing midlength	Variable, sometimes within a genus, intergrading	Unknown
Cu [CuA] fork	Triangular	Not mentioned	Triangular	Broad subquadrangular	Character poorly defined	Unknown
Cu1b [CuA2]	Not recurrent or very short	Rather long, sometimes recurrent	Long, not recurrent	Recurrent	Variable	Unknown

Nomenclature of veins follows Burckhardt & Poinar⁴, terms used by Shcherbakov⁹ are given in brackets.