Browsing by Author "Vanavasan, N.K."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    The slug Mariaella dussumieri Gray - an economically important pest of arecanut palms
    (Indian Society for Plantation Crops, 2009-04) Mariamma Daniel; Vanavasan, N.K.
  • Thumbnail Image
    Item
    Status of Homopterans on Areca Palms and their Natural Enemies
    (2002) Mariamma Daniel; Vanavasan, N.K.; Keshava Bhat, S.
    Areca palm, Areca catechu Linn. Is now cultivated in an area of about 268 thousand hectares {1997-98) and this has almost doubled since 1971-1972. Young plantations practising monoculture of areca palms bring in many new pest problems. Of these, many species of homopterans including five genera of armoured scale insects, two species of mealy bugs, one species each of palm aphid and aleyrodid are noticed. Few plant hoppers are also found colonising the leaves.Two species of scale Insects Including Aonldlelta orientalls (Newst.) colonise the leaves and developing fruit bunches. The feeding results In characteristic yellowing of the leaves and loss of vigour in severely damaged fruit bunches. The mealy bugs, especially Planococcus sp are mostly seen on leaflets, inside the leaf sheaths, on the inner angle of spadices and on Inflorescences. They also colonise developing fruit bunches. Mealy bug infestation on inflorescence along with the association of nest building ants may lead to the drying up of the same. A species of whitefly is also gaining Importance especially in young plantations. It infests the leaves of areca palm. Both nymphs and adults of these suck the sap from the leaves. Further disfiguration of the leaves is caused by the honeydew secreted vy them. The honeydew attracts the growth of sooty moulds. The palm aphid, Cerataphis sp. Is emerging as a major problem on developing inflorescences. This aphid colonises all parts of inflorescence viz, the rachii, the rachillae, female flowers and developing fruits. Colonies are also seen on leaflets and on the spathes covering the unopened spadices. Shedding of female flowers and young fruits occur due to the feeding of this aphid. The indigenous natural enemies of these hompterans including parasites, predators and insect pathogens are being discussed. Coccinellids, preda-ceous thrlps and mites, and parasites on scale insects, a syrphid and a chrysopid on palm aphid and a parasite and a coleopteran predator on whitefly are the indigenous natural enemies observed so far.