鳳梨粉介殼蟲之生態與鳳梨萎凋病關係之研究
Other Title
Study on the Ecology of Pineapple Mealybug (Dysmicoccus brevipes Ckll) in Relation to the Pineapple Wilt
Journal
植物保護學會會刊
Journal Volume
6
Journal Issue
3
Pages
114-120
Date Issued
1964-09
Date
1964
Author(s)
李錫山
Abstract
從萎凋病株上所採之粉介殼蟲，接種後雖以最少之蟲數10隻，停留15天，在接種後40天左右，便顯出萎凋之徵象，蟲數多者，其萎凋病率亦隨之增加，而其最高萎凋率之持續時問，與接種蟲數之多寡成比例增加。同樣之蟲數，其停留時間之久暫，與其發生萎凋之程度，及其最高萎凋率持續之時問均無顯著之差異。無論蟲數之多寡與停留之久暫，其達最高萎凋率所需之日數，亦無差異，而且頗相近似，平均在108天左右。粉介殼蟲於接種後停留期滿以殺蟲劑將其消除，但萎凋病之發生，多在其後才陸續顯現。
粉介殼蟲接種後，因萎凋病之發生，鳳梨之植株更形矮小，而且生育亦受影響，無論其植株之高度，新葉之發生均顯著地減少，其差異之程度，因接種症、數之多寡並馳時間之延長越見顯著。
粉介殼蟲於接種後停留時間屆滿時，其蟲口之密度，大多較接種時類多數倍，且因接種時間較長者，其增加之蟲數越多。接種後粉介殼蟲之分佈大多在從心葉起之30葉以內較多，越向外圍之葉，蟲數越少，惟停留之時間越長，則其分佈亦漸擴及外圍之葉。此種現象，可能非由於粉介殼蟲本身之移動，而因鳳梨之生育係從心部之葉長出，所以其原來所棲息之葉乃隨心葉之繼續長出而外向堆移。事實上，依粉介殼蟲之習性，喜在幼嫩之部位為害，所以粉介殼蟲顯然向心葉移動，否則，心葉必無粉介殼蟲之存在。
粉介殼蟲在葉部之棲息位置，很明顯地集中於基部之淡綠色部位僅極少數在於近心葉之白色基部和綠色部位。Carter氏謂粉介殼蟲必需在鳳梨葉基部淡綠色部位為害方有萎凋發生，若在葉之上部深綠色部位為害者，除蟲數很多奢外，不會引起萎凋。由本試驗調查之粉介殼蟲棲息位置與其萎凋之發生情形觀之，與氏之所云頗相吻合。
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.
Subjects
鳳梨粉介殼蟲
鳳梨萎凋病
Publisher
植物保護學會
Type
journal article
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