The current report from the east coast of India is a continuation of work on these organisms begun in 1955. Emphasis is now placed upon the incidence of Limnoria sp. in association with teredines and an evaluation of the natural resistance of four species of timber against marine borer attack. This is the first time that a heavy attack by Limnoria sp. from the east coast of India has been reported.

Test panels of Cedrela toona, Aegle marmelos, Terminalia paniculata and Xylia xylocarpa used for piles, catamarans, fishing floats, canoes and fender piles were exposed at Madras harbour for a six month period (May-November, 1970) and examined for the degree of activity of the borers and their significance in the durability of these timbers.

L. pedicellatus together with Limnoria sp. are responsible for damage to C. toona and T. paniculata while the other two were infested moderately by teredines. Limnoria sp. hitherto reported as scarce, is of common occurrence like pholads and teredines. The preference of Limnoria sp. to C. toona and T. paniculata and not to A. marmelos and X. xylocarpa is of interest and importance. The durability of the four species of timbers can be arranged in the following order: A. marmelos (most resistant), X xylocarpa, C. toona and T. paniculata (least resistant).

The occurrence and settlement of foulers Balanus sp. and Hydroides sp. have been studied. The observations are discussed with reference to hydrographical conditions and earlier reports.