|Title:||鳳梨粉介殼蟲之生態與鳳梨萎凋病關係之研究||Other Titles:||Study on the Ecology of Pineapple Mealybug (Dysmicoccus brevipes Ckll) in Relation to the Pineapple Wilt||Authors:||李錫山||Keywords:||鳳梨粉介殼蟲;鳳梨萎凋病||Issue Date:||Sep-1964||Publisher:||植物保護學會||Journal Volume:||6||Journal Issue:||3||Start page/Pages:||114-120||Source:||植物保護學會會刊||Abstract:||
This paper deals with the relationship between the rnealybuy (Dysmicoccus brevipes Ckll) and the pineapple wilt by inoculating various number of mealybugs for staying a certain periods of infestations at the different growing stages of pineapple, The first inoculation was carried out about 40 days after the pineapple plan ted. Mealybugs were taken from wilt plants, on every fifteen potted pineapples, 10, 25 and 50 individual third instar mealybugs were then respectively inoculated to each plant. Each number of inoculated mealybugs was allowed to infest in the pineapples for the periods of 15, 30 and 6 days re3pectively, then the mealybugs, on ten of the fifteen inoculated pInts, were killed by dipping them into insecticide, the other five plants were pulled out at the same time for inspecting the mealybugs, in order to ascertain, on what parts of the leaf that mealybugs are usally feeding.
Up to now, there are only two inoculations that were completed at the stages both about one month and seven months after the pineapple planted. The first typical wilt had been presenting significantly in the first inoculated plants about forty days after the mealybugs had been placed. The peak of the wilt in all of the treatments lasted a period of approximately 108 days from inoculations despite either the number of mealybugs inoculated or the days that mealybugs stayed. The evidence is also presented that the higher percentage of wilt caused by the large number of mealybugs showing a still longer period of wilt than that of the less number of mealybugs, but, the same number of mealybugs presented no difference of wilt between the different periods of infestation.
The growth of pineapple was reduced gradually after the mealybugs infesting, it is due to the fact that while the pineapples are getting wilt, the leaves dropped down, further, the affected leaves have dried up for the greater part of the length, the growing rate of the leaf, that coining out from the center of the plant, was also reduced significantly between the number of the mealybugs inoculated as the time lasting longer.
Mealybuys mostly established within the thirty inner leaves, but it is always getting outer of the leaves as the mealybugs stayed a longer period, this phenomenon may be due to the fact that the leaves that mealybugs established would be naturally getting outer as the new leaves coming out from the center of the plant, The evidence here is also presented that most of the mealybugs establised on the lower portion of the leaf, according to W. Carter, on which part that mealybugs feed, however, would easily produce the pineapple wilt.
|Appears in Collections:||植物保護系|
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