Abstract

The biology of Sahyadrassus malabaricus on teak [Tectona grandis] and Trema orientalis was studied in the field in Kerala, India. Most adults emerged in late April-May, in the pre-monsoon season. Eggs were laid soon after emergence and larvae appeared on saplings about 3 months later, it is suggested that early larval instars survived elsewhere and migrated to saplings. The larvae fed on bark, particularly on callus tissue in the vicinity of the tunnel mouth, under a thick meshwork of bark, wood andfrass. Fifteen new food plants are recorded, bringing the total to 50 species of woody shrubs and trees. T. orientalis was the most acceptable food plant, harbouring as many as 30 larvae/tree, while multiple infestation was rare in other hosts. Predationby woodpeckers and infection by the entomogenous fungus Metarhizium anisopliae were recorded. In some 2-4-year-old Tectona grandis plantations, 6-61 of saplings were attacked, but economic damage was negligible. Plantations of Albizia