|Title:||柑桔紅蜘蛛(Paonychus citri (McGregor))之生態觀察||Other Titles:||Observations on the Ecology of Citrus red mite (Panonychus citri (McGregor)) In Taiwan||Authors:||鄭清煥
|Keywords:||柑桔紅蜘蛛||Issue Date:||Mar-1966||Publisher:||植病保護學會||Journal Volume:||8||Journal Issue:||1||Start page/Pages:||80-89||Source:||植物保護學會會刊||Abstract:||
According to the laboratory rearing the citrus red mite took 25 generations from 5, Oct. 1964 to 15, Oct. 1965, at the average temperature and relative humility of 18-30℃ and 64-80 per cent. The average number of eggs laid by each female was 62, the range being from 18 to 87, and the average number of eggs laid by each female per day was 3.06, the range being from 0 to 14. Eggs generally hatched from 2 to 15 days, with an average of 5.40 days, and the stages of larva, protonymph, deutonymph took an average of 2.37, 2.11, 2.28 days, ranging 1-7, 1-6, 1-9 days, respectively. The time required for egg to adult average 12.21 days in female, ranging from 7 to 30 days, while in male, it took average of 11.31 days, ranging from 6 to 23 days.
Based on one year’s observation, it was found that the citrus red mite took about one month to complete a life-cycle during December, January and it took more than two generations each of the other months.
Both sexes of citrus red mite were found to have a larval and two nymphal stages. each followed by a resting stage. Some male could mature without the stage of deutonymph .instar. Mating process was usually accomplished immediately after the last molt of the female; Eggs from unfertilized female gave rise to males only and those from fertilized feia1e to a preponderance of females.
Field obsevations revealed that citrus red mites usually build-up more dense and large colonies in the well managed citrus orchard, plants rceived plentiful sunlight, and younger leaves; in neglected orchard, shaded plants, and older leaves, mites generally are scarce. Applications of insecticide in dis-order were also conductive to increase of mite population.
The climatic data in central and southern part of this island indicated that both temperature and humidity were very suitable for citrus red mite to develop all the year round, and the rainfall seems to be the major factor that directly influenced the seasonal fluctuation of mite’s populations. It was found that citrus red mite’s population on Valencia orange trees tended to be the highest during the dry late-fall, winter, and spring seasons, and the raininess or that accompanied with the result of typhoon were noted to have reduced the spring population and
maintained a low population through-out the sunmer.
|Appears in Collections:||植物保護系|
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