Abstract

About 100 species of commercially important timber species are being extracted from the natural forests in Kerala and stored in depots. The stored timber is often attacked by borers belonging to the insectorder Coleoptera. In the present survey, about 53 species of beetles were recorded as pests of one or more of 46 species of stored timber. These belong to the families, Cerambycidae, Bostrychidae, Lyctidae, Platypodidae, Scolytidae, Curculionidae and Anthribidae. the major cerambycid borers collected in this study were, Batocera rufomaculata (attacking Bombax ceiba, Ceiba pentandra, Mangifera indica and Syzygium cumini); Olenecamptus bilobus (attacking Artocarpus hirsutus and Lagerstroemia microcarpa) and Xystrocera globosa (attacking Albizia odoratissima). They generally attack the sapwood as well as heartwood of freshly felled timber with intact bark. Borers belonging to the other families are small in size but often cause considerable economic loss. They generally attack the sapwood. Maximum damage is caused to the low density timbers having marked sapwood portion. Finished products such as match veneers, plywoods, packing case boards, brush-handles, bobbins, photo-frames. etc., made out of these timbers are heavily damaged in godowns and storage yards. The major borers noticed during the present survey were: Dinoderus minutus, Heterobostrychus aequalis, Sinoxylon anale (Bostrychidae); Lyctus brunneus, Minthea rugicollis (Lyctidae); Platypus slolidus, p. latifinis (Platypodidae); Xyleborus similis and X. interjectus (Scolytidae). The important timbers damaged by these borers include, Ailanthus triphysa, Anacardium occidentale, Bombax ceiba, Ceiba pentandra, Canarium strictum, Erythrina indica, Hevea brasiliensis, Mangifera indica, Polyalthia fragrans, Tetrameles nudiflora and Vateria indica. For easy identification of important borers, a pictorial key was prepared for each borer family dealt with in this work