Some studies on the biology and seasonal variation in the population of Monalonion annulepis Sig. in Costa Rica
Studies on the biology and seasonal variations of the population of Monalonion annulepis Sig. were conducted at Turrialba and La Lola, Costa Rica, in 1965 and 1966. The biological studies showed that the insect much preferred to lay eggs in the soft tissue of young shoots, rather than in cacao pods or young seedling plants. Oviposition took place on the first day and continued for only three days after copulation under captive conditions. High relative humidity (above 90 percent) was required to maintain the eggs in a viable condition for the 18-day incubation period. Nymphs required about 17 days to complete their development to adults and showed amarked preference for feeding on mature rather than immature or green cacao pods. Adults survived under caged conditions for only a few days. This coupled with the difficulty of preventing the oviposition and feeding substrates from being invaded by fungi and dessicating, made mass rearing attempts with these insects generally unproductive. Field surveys over 15 months suggested that mirids are more numerous on unshaded cacao areas and peak populations in both unshaded and shaded areas occurred during the October-November growing period. Readily available food supplies (leaf flush) and relatively high range of temperature (difference between the mean monthly maximum temperature and the mean monthly minimum temperature) above 8 grade centigrade and high relative humidity appeared to be necessary for major population increases. Estimations of the die-back intensity on shaded and unshaded cacao at different times of the year suggested that overhead shade was important in cacao in preventing die-back and within shaded areas the development of die-back was directly related to the extent of mirid feeding on terminal branches.
| Main Authors: | , |
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| Format: | biblioteca |
| Language: | spa |
| Published: |
Wisconsin (EUA)
1967
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| Subjects: | THEOBROMA CACAO, MONALONION ANNULIPES, MIRIDAE, DISTRIBUCION NATURAL, CICLO VITAL, HABITOS ALIMENTARIOS, OVIPOSICION, EVOLUCION DE LA POBLACION, FINCA LA LOLA, COSTA RICA, |
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