Abstract

Studies on the biology and the host range of Orosius albicinctus Dist., the vector of Sesamum phyllody disease were made under field and insectary conditions. Tho mean duration of egg stage varied from 6 to 11 days, the total nymphal period 14 to 17 days and longevity of adults from 20 10 67 days in different seasons. The sesame MLO did not have any adverse effect on the longevity and fecundity of the vector. The vector bred successfully on 17 species of plants. among them seven. species of plants viz., Crotolaria juncea L. Sesamum laciniatum Kloin, Solanum melon- gena L.. Sphaeranthus indicus L.. Gyandropsis pentaphylla DC. Cleome viscosa L., and Trichodesma indicum RB.. were utilised successfully for breeding under field conditions. It oviposited on Arachis hypogaea L. Cajanus cajan L.. Gossypium hirsutum L., and Abutilon indicum G. and the nymphs perished without attaining maturity. It neither oviposited nor survived for long periods on 43 species of plants belonging to 12 families.

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