Further forms of Rutherfordia, with particular reference to the second-instar males (Sternorrhyncha: Coccoidea: Diaspididae).

Ten new forms or species of scale insects are described from Malaysia as members of the genus Rutherfordia MacGillivray. Five of them are formally named, and the other five are treated under temporary names. With the type species, its possible variegated forms, and two other known species added, the genus now comprises at least 13 species distributed in tropical and subtropical Asia. They are referred to the genus on account of their possession of two unusual characters in the adult females. They are far from uniform in other characters of the adult females, and are diverse also in the second-instar males and even in the first-instar nymphs. They are not divisible into groups which are recognizable consistently through the different stages. In this respect, the known species may be interpreted to represent fragments from intricate diversification within the genus. The second-instar males of four species, not all of these species being closely related to each other so far as based on the adult females, agree in having extraordinary prominent processes on the posterior end of the abdomen. The probable function and possible origin of these processes, ‘mandibles on the abdomen’, are given