溫度對唐菖蒲薊馬發育之影響及其在唐菖蒲植株之分布

Abstract

觀察唐菖蒲薊馬在15、20、25及30℃等四種溫度下之發育期，結果卵期、 幼蟲期(第一、二齡)、前蛹期及蛹期均隨溫度升高而縮短，在30℃中可得 最短之發育期，分別是3.3日、1.4日、2.4日、1.0日及2.1日。各發育育 期之發育速率(Y)與溫度(X)作一次迴歸方程式，二者呈現正線性關係，並 利用X截距法求得各蟲期發育臨界低溫及總積溫，其中以蛹期發育臨界溫 度最低為8.1℃，而第一齡幼蟲最高為12.5℃；在總積溫中以卵期所需日 度67.6DD最長，以前蛹期所需19.2DD最短。探討卵孵化率及各發育期之死 亡率，結果在15℃中卵孵化率最低為57﹪；第一、二齡幼蟲、前蛹和蛹期 在15℃中死亡率亦最高分別為7.8﹪、11.1﹪、17.8﹪及34.4﹪。顯示15 ℃在四種溫度中最不適合唐菖蒲薊馬發育。行孤雌生殖或行兩性生殖之雌 蟲，二者在不同溫度之產卵前期及產卵期，均隨溫度增高而縮短，如未交 尾及已交尾之雌蟲分別在30℃中可得最短之產卵前期2.0日及 2.0日，產 卵期15.0日及14.5日；並在四種溫度下呈顯著差異。二者在每日產卵量方 面，亦隨溫度增加而增加，其中未交尾雌蟲在30℃中可得7.3粒，已交尾 為7.2粒；但在生總產卵量上，溫度對未交尾及已交尾雌蟲之產卵影響不 大。將雌蟲壽命(Y)與溫度(X)作一次迴歸方程式，則無論是行何種生殖方 式之雌蟲，二者之壽命均與溫度呈負線性關係。唐菖蒲薊馬在田間唐菖蒲 植株上之分布，發現卵、幼蟲、蛹期及成蟲均於花部所佔最高，分別為73 ﹪、69﹪及51﹪。而蛹期以在嫩葉為54﹪最高。唐菖蒲薊馬密度均隨植株 生長而增加，並有向花部聚集之趨勢。如開花期，成蟲於花部可達13隻， 佔52.7﹪，幼期可達138.3隻，佔79.1﹪。以Index of dispersion, Green's coefficient of dispersion,Morisita;s

efficeint of dispersion, Lloyd's mean crowding index 及Taylor power law等學說評估薊馬於田間之空間分布，結果無論使用何種指數， 均顯示唐菖蒲薊馬具有聚集分布之傾向。The development of Thrips simplex were observed at 4 different temperature:15,20,25 and 30℃.The results indicated that the developmental duration of eggs, larvae, prepupae and pupae decrease as the temperature increases.The minimun averagevelopmental durtion at 30℃ forthe stages were 3.3,1.4,2.4 anddays, respectively. The development rate(Y) of each stage is proportional to the temperature(X).The low development threshold and the thermal summation for each stage were 10.0℃,67.6DD,12.5℃,24.8DD,9.4℃,47.6DD,11.7℃,19.2 DD,8.1℃,46.5DD.Studies of egg hatching rates and motality of developmental period found thate hatching percentage at 15℃ was minimum with the average of 57.0﹪. The mortality at 15℃ for the stages of 1st larva(7.8﹪), 2nd larva(11.1﹪), prepupa(17.8﹪) and pupa(34.4﹪) were the highest among the 4 different temperatures. The result showed that the temperature 15℃ was the most unsuitable for Thrips simplex development among the 4 temperature. The pre-oviposition and oviposition under different temperatures of female which takes parthenogenesis or bisexual reproduction decreases as temperature incereaes. While the minimum pre-oviposition and oviposion period of virgin female at 30℃ were 2.0 and 15.0 days, the minimum pre-oviposition period and oviposition period of mated remale were 2.0and 14.5 days.The daily egg production increases as the temperature increases.There were no significantly differences between the eggs produced by a virgin female and a mated female at 15,20,25 and 30℃. The longevities of a virgin female and a mated female decrease as the temperature increases.The longevities(Y) of adults(virgin and mated) and temperature(X) were negative linear relationships.