Une ennemie du palmier a huile: la mineuse des feuilles
A small coleopter, Coelaenomenodera elaeidis, which is 4 to 6 mm in length, constitutes a very deal danger to oil palm plantations in Africa. The larvae, 5 mm long before nymphosis, mine the palm leaflets and the foliage in a palm grove can thus be completely destroyed. Reported as long ago as 1910 in Ghana, the insect has caused particular damage in the La Mé plantation in the Ivory Coast in 1948, 1961 and 1964, in Dahomey in 1958 and 1964, and recently in the Cameroons. The life cycle of the insect is about three months, only the adult stage occurring outside the leaves. As no insecticide has yet been shown to be effective against the larvae, control is effected at the adult stage, before egg-laying, when the population is increasing rapidly. For this reason, the development of the cycle must be followed very carefully by fortnightly observations in order to estimate the size of the population and to trace development graphs of the percentage of adults, larvae and nymphs. For maximum efficiency, treatments must be applied seven days after the beginning of the reduction in the number of nymphs, but this treatment is only necessary if the total population exceeds the critical threshold empirically defined for each plantation. Adult insects are treated by dusting with BHC (20 kg per hectare of dust containing 25 percent of active ingredient) or by spraying with Dieldrin (1 kg per hectare of active ingredient). Trials are still in progress for the production of insecticides capable of reaching the larvae in their galleries. The biological equilibrium must not be ignored. Before a treatment is decided upon, the rate of natural parasitism must be taken into consideration
| Main Authors: | , , , , |
|---|---|
| Format: | biblioteca |
| Published: |
Londres (Inglaterra)
1965
|
| Subjects: | ELAEIS GUINEENSIS, COLEOPTERA, INSECTOS DEPREDADORES DE LAS HOJAS, COELAENOMENODERA ELAEIDIS, CONTROL DE INSECTOS, |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | A small coleopter, Coelaenomenodera elaeidis, which is 4 to 6 mm in length, constitutes a very deal danger to oil palm plantations in Africa. The larvae, 5 mm long before nymphosis, mine the palm leaflets and the foliage in a palm grove can thus be completely destroyed. Reported as long ago as 1910 in Ghana, the insect has caused particular damage in the La Mé plantation in the Ivory Coast in 1948, 1961 and 1964, in Dahomey in 1958 and 1964, and recently in the Cameroons. The life cycle of the insect is about three months, only the adult stage occurring outside the leaves. As no insecticide has yet been shown to be effective against the larvae, control is effected at the adult stage, before egg-laying, when the population is increasing rapidly. For this reason, the development of the cycle must be followed very carefully by fortnightly observations in order to estimate the size of the population and to trace development graphs of the percentage of adults, larvae and nymphs. For maximum efficiency, treatments must be applied seven days after the beginning of the reduction in the number of nymphs, but this treatment is only necessary if the total population exceeds the critical threshold empirically defined for each plantation. Adult insects are treated by dusting with BHC (20 kg per hectare of dust containing 25 percent of active ingredient) or by spraying with Dieldrin (1 kg per hectare of active ingredient). Trials are still in progress for the production of insecticides capable of reaching the larvae in their galleries. The biological equilibrium must not be ignored. Before a treatment is decided upon, the rate of natural parasitism must be taken into consideration |
|---|