Abstract

Recent studies carried out in the sandal reserve forests of Marayoor in Kerala by the authors indicated Redarator bimaculatus Dist., an Issid, as a possible vector of sandal spike disease. The insects collected from spiked sandal trees in sandal reserve 51 of Marayoor forest range were released on severely spiked shoots for acquisition access period of 24 to 120 hours. Of these 2 to 17 insects were released on 1- to 2-year old seedlings raised in insect proof cages and 4-year old trees in the field. Spike like symptoms developed after three months in seedlings whereas it took about 6 months in trees. Petiole and stem tissues from these trees showed numerous pleomorphic mycoplasma-like organisms (MLO) in the pholem tissue under electron microscope which were comparable with the MLO observed in naturally infected sandal tree. Tissues of intestine and salivary glands of Redarator bimaculatus also showed MLO after acquisition feeding