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Cord Trapping-a Major Tactic Of BIPM Stretegy Of Palm Weevils

Several species of curculionid weevils such as Amerrhinus ynca Sahlberg, Cholus annulatus Linnaeus, C. martiniquensis Marshall, C. zonatus (Swederus), Diocalandra frumenti (Fabricius), Dynamis borassi Fabricius, Homalinotus coriaceus Gyllenhal, Metamasius hemipterus Linnaeus, Rhabdoscelus obscurus (Boisduval), Rhinostomus barbirostris (Fabricius), R. afzelii (Gyllenhal), Rhynchophorus bilineatus (Montrouzier), R. cruentatus Fabricius, R. ferrugineus (Olivier), R. palmarum (Linnaeus) and R. phoenicis (Fabricius) are associated with palms. Some of these have   become a major constraint in the successful cultivation of coconut palm (Cocos nucifera L.), date palm (Phoenix dactylifera L.) and oil palm (Elaeis guineensis L.). R. ferruginus is distributed in over 31 countries and attacks more than two dozen palm species. In the recent past, it has spread to Middle Eastern countries, Mediterranean region of Africa and southern Europe (Spain) causing tremendous economic losses. The yield of date palm has decreased from 10 to 0.7 tons/ha. Coconut palms in India are infested upto 6.9 per cent in Kerala and 11.65 per cent in Tamil Nadu. R. palmarum is a major pest of cultivated oil and coconut palms in the tropical Americas and, vectors the nematode, Bursaphelenchus cocophilus (Cobb) Baujard which causes red ring disease (RRD). Palm losses due to RRD are commonly between 0.1 to 15% which amounts to to tens of millions dollars. The status of other species is briefed. Direct damage is caused by the grubs of weevils that develop in the stems, bud, rachis of leaves, and inflorescence of cultivated, ornamental, or wild palms. Because of the cryptic habitat of the grubs which act as tissue borer, the management becomes difficult. Twenty-three species of natural enemies are associated with palm weevils. The traditional method of controlling palm weevils included sanitation, pesticides and poisoned traps baited with damaged tissue of coconut, sugarcane, pineapple or banana fruits.


     Kairomones such as pure ethanol or isoamyl-acetate have been found as attractive as or even more attractive than natural plant tissue (pineapple vs. isoamyl-acetate). Palm weevils (Rhynchophorus palamrum, R. phoenicis, R. vulneratus, R. ferrugineus D. borassi, M. hemipterus, R. obscurus, and P. distortus) use male-produced aggregation pheromones for intraspecific chemical communication, (4S, 5S)-4-methyl-5-nonanol (ferrugineol) is the major aggregation pheromone for R. ferrugineus, R. vulneratus, R. bilineatus, M. hemipterus, and D. borassi and a minor component for R. palmarum, (5S, 4S)-5-methyl-4-octanol (cruentol), (3S, 4S)-3-methyl-4-octanol (phoenicol) and (4S, 2E)-6-methyl-2-hepten-4-ol (rhynchophorol) are the main aggregation pheromones for R. cruentatus, R. phoenicis, and R. palmarum, respectively. Plastic bucket modified into pheromone trap with synthetic pheromone and synergist (sugar cane stalk or palm petiole, or banana fru

.it)  immersed with carbofuran, hung on palms stems at about 1.5-1.7 m above the ground formed a sustained pheromone based trapping system.The sugessions for future management initiatives including areawide trapping, and formulation of an international network project are given.

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