Discovery of a sooty mould scavenging beetle, Leiochrinus nilgirianus Kaszab (Coleoptera: Tenebrionidae) on coconut palms infested by the invasive rugose spiralling whitefly, Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae)

Abstract

A novel discovery of a Leiochrini beetle, Leiochrinus nilgirianus Kaszab (Tenebrionidae : Coleoptera) associated with scavenging action on the sooty mould deposits on coconut palm that are developed on the honey dew excrements from invasive rugose spiralling whitefly, Aleurodicus rugioperculatus Martin was reported for the first time. Adult beetles, averaging 2.07±0.9 / leaflet, with a maximum of five beetlesper leafletand immature stages were generally confined to the undersurface of the palm leaves during daytime, but were found feeding on sooty mould during morning hours in damp conditions. The specially aided adaptive leg features of L. nilgirianus with bristle-like hairs on the undersurface of tarsomeres could probably aid in scooping / brushing the sooty mould deposition and well developed tarsal claws thatperhapsassist swift movement on fungus-laden leaflets. On an average one adult beetle could clear 1-2 mm2 sooty mould laden area in a period of one minute. In situ habitat conservation of L. nilgirianus appears to have the potential to save several crores of rupees in the agricultural sector by avoiding chemical pest management options.