|Title:||粉介殼蟲(Dysmicoccus brevies (Ckil.))在鳳梨果實上之發生時期調查及其防治試驗||Other Titles:||Seasonal abundance of Mealybug (Dysmicoccus b,revipes (Ckll.) ) and Its Control on Pineapple Fruits||Authors:||李錫山
|Keywords:||粉介殼蟲;鳳梨||Issue Date:||Dec-1967||Publisher:||植病保護學會||Journal Volume:||9||Journal Issue:||3-4||Start page/Pages:||59-66||Source:||植物保護學會會刊||Abstract:||
本省鳳梨果實粉介殼蟲之為害率相當高，平均為29.43%，且年中均有，以三至六月份之為害率較高，平均為33.75%，至44.08%，而以十二月份最低，平均為15.17%。全省鳳梨果實粉介殼蟲之為害率，以高雄地區37.3%為最高，次為坐南33.5%和嘉義32.25%，再次為南投19.28%。粉介殼蟲在鳳梨果實，以果基及果柄為最多，僅少數在裔芽及冠芽。至殺蟲劑之防治比較結果，在鳳梨謝花後一個半月左右以大利農Diazincn 0.04% (1:1,500)噴射兩次，每次相隔17天。每次每株噴300cc,其防治效果可達100%。
Mealybug (Dysmicoccus brevipes (Ckll.) ) has been satisfactorily controlled in Taiwan by using parathion at the concentrate of 0.0235% (1:2000) for slips dipping and followed by three times filling with the same material in field with an interval of three months. This remedy, for control the mealybugs which induce the wilt of pineapple, has been proved to be more effective to eliminate the wilt by suppressing the population of the pest on pineapple in the early stage(4). Therefcre, the applica tions of insecticide to pineapple, for the purpose of wilt elimination, in the period about several months before blossom were not so important as those in the period within one year after planting. As a result, the survival of mealybugs will crawl up to the newly formed fruits and most of them establish on the portion between the upper end of stalk and the bottom of fruit, a less number of them on slips and crown only.
In recent years, fresh pineapple exporting has been developed rapidly, nearly twenty thousand metric tons of fresh fruit were expcrted annually. It has arrested our attention to the fruits on which mealybugs contaminated were not permitted to be exported.
A project of mealybug control on pineapple fruits was then laid out in order to solve the problem as it is mentioned above. Before the control program was put into action, a survey of seasonal abundance of mealybug on pineapple fruits was conducted in several districts, such as Nantow, Chiayi, Tainan and Kaohsiung, in which area pineapple was considered to be more concentrically grown.
Six investigations were given from December 1966 to August 1967. Fifty fruits of
pineapple were examined in each field, two to four of which were randomly investigated in each district.
The result (Table 1) indicated that the infestation of mealybugs on pineapple fruits becomes more serious gradually from D2cember to June as the temperature raises from month to month in this duration. But the infestation was suppressed to be lower in July since the rainfall that almost concentrates in the months from May to August. On the other hand, the infestation of mealybug in the investigated districts (Table 2 ) varied greatly from south to the middle of this island. It is also partially affected by the climate that is warmer crderly frcm Kachsiung to Nantcw. On the whole, mealybugs occur almost through the year on pineapple fruits and the mean percentage of infestation in this island is 29.43%.
The control program was carried out both in the laboratory and field. Six chemical compounds namely Orthc-9006 72%EC, Malathion 50%EC, Sumithion 50%EC, Lebaycid 50%EC, Matacil 75%WP and Diazinon 60%EC, etc., some of which have been used on banana for control the same mealybug as that on pineapple, were firstly tested at laboratory by dipping ten slips into each concentration for two minutes. Mortality was counted seven days after treatment. The result was given in Table 3.
Four compounds such as Diazinon, Lebaycicl, Surnithion and Matacil which selected from laboratory screening were thin tested in field. Insecticides were sprayed on fruits in the stage about two months before harvesting. Diazinon sprayed 300cc per plant at the concentrate of 0.04% (1:1500) for two applications at the interval of 17 days giving 100% control as it is showed in Table 4.
|Appears in Collections:||植物保護系|
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