Horniolus sororius Poorani 2015

Horniolus sororius Poorani

(Fig. 2)

Horniolus sororius Poorani, 2015: 7 (holotype male; NBAIR).

Diagnosis. Length: 2.20–2.65 mm; width: 1.65–1.80 mm. Form (Fig. 2a, b) elongate, oblong oval, dorsum moderately convex and densely pubescent. Head and pronotum dark testaceous brown, elytra dark pitchy brown to black, each elytron with a pair of bright orange-yellow spots, anterior spot transverse, subrectangular with a wavy margin, posterior spot transverse oval and smaller, not reaching sutural or lateral margins, both spots occasionally larger, almost touching lateral margins of elytra. Ventral side dark reddish brown, except legs lighter, yellowish brown. Abdominal postcoxal line (Fig. 2c) complete and semicircular, area enclosed by postcoxal line sparsely punctate with few punctures along anterior margins. Male genitalia (Fig. 2e–g) and spermatheca (Fig. 2d) as illustrated.

Distribution. India: Karnataka; Kerala; Tamil Nadu.

Prey/associated habitat. Predatory on Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae); Ferrisia virgata (Cockerell) (Hemiptera: Pseudococcidae); associated with mealybugs infesting coffee, garden plants, hedgerows and avenue trees such as Spathodea campanulata and Bauhinea purpurea; on Eleusine coracana (label data).

This species was recorded by Ramani et al. (2002) (as Horniolus sp.) as a predator of A. dispersus. Irulandi et al. (2001) recorded this species as H. vietnamicus Miyatake, 1976 and studied its biology on coffee mealybug, Planococcus lilacinus. Najitha (2016) and Vidya & Bhaskar (2017) recorded it as a predator of pepper root mealybug (Formicococcus polysperes Williams) from Kerala, South India.

Seasonal occurrence. Collected in June, September, December (label data).

Note. This species has a superficial similarity with Scymnus (Pullus) latemaculatus Motschulsky, 1858, one of the most commonly collected species of this region. Horniolus sororius can be differentiated from S. latemaculatus by the comparatively more elongate body outline, presence of a mixture of dark and paler setae on the elytra, prosternal carinae, and the genitalia.