Genus Horniolus Weise

Horniolus Weise, 1901: 442. Type species: Horniolus dispar Weise, 1901, by monotypy.

Diagnosis. Form elongate, oblong to broadly oval, dorsum moderately to strongly convex, densely pubescent, elytral pubescence often comprising a mixture of dark and paler hairs. Head with expanded clypeus, eyes with a distinct but narrow ocular canthus.Antennae with 11 antennomeres. Scutellar shield large, triangular and prominent. Prosternal carinae inverted Y-shaped with a short stem. Abdominal postcoxal line complete, deeply semicircular, or apically obliterated and apparently incomplete (Chen et al. 2016). Tarsal formula 4-4-4. Female genitalia with a complex, coiled spermatheca, coxites elongate triangular.

Note. Many species of this genus have a similar external appearance with the ground colour black to dark pitchy brown with yellowish-orange elytral maculae, often in the form of four orange yellow elytral spots of various sizes / shapes. This genus is generally poorly represented in institutional collections and due to its general resemblance to other Scymnini, it is likely to be difficult to spot in mixed collections.

Biology/ Hosts. Members of Horniolus mostly prey on mealybugs, such as Planococcus lilacinus (Cockerell) and Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae), infesting coffee, tea and pineapple. These beetles also feed on spiralling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae) (Irulandi et al. 2001; Ramani et al. 2002; He et al. 2013; Poorani 2015; Chen et al. 2016; label data).