台大實驗林杉木林中小蠹蟲種類及族群變化

Species and population changes of scolytids (Coleoptera: Curculionidae: Scolytinae) in Chinese-fir (Cunninghamia lanceolata) in NTU Experimental Forest

林清山(Ching-Shan Lin)

指導教授 ： 吳文哲

國立臺灣大學/生物資源暨農學院/昆蟲學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.01779

摘要

杉木(Cunninghamia lanceolata) 屬針葉植物，是重要的建築木材，具經濟重要性。小蠹蟲（scolytid）屬象鼻蟲科的小蠹蟲亞科（Curculionidae: Scolytinae）為林木重要的經濟害蟲，亦有多種列為檢疫害蟲；被認為是造成2002年台灣中部多處杉木萎凋枯死的元兇。因小蠹蟲受林木所釋出的氣味所吸引，本試驗利用α-蒎烯（α-pinene）及乙醇（95% ethanol）二種混合誘引劑以林根氏多層誘蟲器（Lindgren multiple funnel traps）調查杉木人造林中小蠹蟲的種類。自2004年6月至2005年5月於台大實驗林內茅埔營林區中的64-7、65-7、69-5及70-3等4個地號土地選為樣區，分別設立3、3、7、12共25組陷阱，試驗期間每60天更換誘引劑，每2週調查1次誘集鞘翅目昆蟲之種類及數目。調查結果顯示共誘得40,366隻小蠹蟲，分屬9族30屬共73種（其中19種僅誘集到1隻），佔誘集鞘翅目昆蟲總數之53.7%（共誘集75,153隻甲蟲，隸屬59科）；其中18種小蠹蟲為台灣已記錄種，2種台灣特有種，27種新記錄種，5種近似種及21種（8種僅捕獲1隻）疑似新種。誘集的小蠹蟲中，以Hypothenemus eruditus Westwood、Phloeosinus pertuberculatus Eggers、Scolytoplatypus pubescens Hagedorn、Xyleborus affinis Eichhoff （屬管制類的小蠹蟲）及Xylosandrus mancus (Blandford)數量最多，各佔誘集小蠹蟲總數之37%、24.4%、7.8%、7.6%及6.4%。為比較陷阱調查之結果，本研究還進行了段木調查，調查方式如下：收集樣區內之枯倒杉木，各樣區取3個1.5公尺長的木頭，各裁截成三段（段木），共進行3次；將段木帶回並用以飼養其內之小蠹蟲，結果共飼養出6科鞘翅目昆蟲，以P. pertuberculatus小蠹蟲的數量最多，佔42.6%（然而在陷阱調查中其數量位居第三）。杉木林中微氣候的變化不大，但大雨或颱風仍可能影響陷阱誘引劑氣味的釋放及小蠹蟲的飛行能力，因此試驗期間有1次颱風影響其後所進行之調查結果，其小蠹蟲的種類及族群數量是全年調查中最少的。文中亦探討鞘翅目昆蟲、小蠹蟲、小蠹蟲與天敵、前5種優勢的鞘翅目種類及小蠹蟲種類在整年調查期間族群之動態。在捕獲的甲蟲中共發現12科小蠹蟲的天敵，當中以隱翅蟲科及出尾蟲科的數量較多。四組樣區中以隱翅蟲科和小蠹蟲出現的相關性較佳（r = 0.73），優勢的小蠹蟲中以H. eruditus與出尾蟲科（r = 0.87）及X. affinis與郭公蟲科（r = 0.88）有極好的相關性。純杉木林中鞘翅目昆蟲及小蠹蟲種的豐富度分別為5.04及5.1，多樣性指數中的辛普森值分別為0.62及0.72，此數據可提供生態保育參考。

關鍵字

小蠹蟲 ； 林根氏多層誘蟲器 ； 天敵 ； 生物多樣性

並列摘要

The Chinese-fir (Cunninghamia lanceolata) belongs to the needle plant with economical significance for the usage of construction lumber. The scolytids (Curculionidae: Scolytinae), that are key pests in the forest and some are also quarantine pests, are likely to cause the dying of Chinese-fir in central Taiwan, 2002. The scolytids are attracted by volatile chemicals released from trees or woods, therefore in this study two lures, α-pinene and ethanol, were used with 12-units of Lindgren multiple funnel traps to investigate the species of scolytids in Chinese-fir plantation. From June 2004 to May 2005 in Nei-Mou-Pu Tract of NTU Experimental Forest, 3, 3, 7 and 12 traps were set in the no. 64-7, 65-7, 69-5 and 70-3 lots, respectively. During the investigation period, the beetles in the 25 traps were collected every other week and the lures were replaced every 60 days. The result showed that 40,366 scolytid individuls belonging to 73 species (including 9 species with only one specimen in the investigation period), 30 genera, and 9 tribes were collected and the number was 53.7% of that of total beetles (75,153 beetles belonging to 59 familes were collected). These 73 scolytid species included 2 endemic species, 18 recorded species, 5 near species, 27 new recorded species and 21 possible-new species (8 species had one specimen only) in Taiwan. The numbers of Hypothenemus eruditus Westwood, Phloeosinus pertuberculatus Eggers, Scolytoplatypus pubescens Hagedorn, Xyleborus affinis Eichhoff, and Xylosandrus mancus (Blandford) were 37%, 24.4%, 7.8%, 7.6%, and 6.4%, respectively, and they were the top five species of attracted scolytids in the collection. Three1.5-meter-length dead woods were collected in each lot, and each wood was cut into 3 lumbers to breed the insects which were collected in these woods. This experiment was repeated three times and it was for the comparison of the beetles in the traps. Finally 6 families of beetles were collected. Phloeosinus pertuberculatus Eggers was the third rich species in the traps; however, it was the most abundant one (accounted for 42.6% of beetles) in the woods. The microclimate changes little in pine forest, but heavy rain or typhoon influences the release rate of lures and the flight ability of scolytids. Therefore, after a typhoon hit Taiwan the numbers of scolytid species and their populations were the least in the investigation. The correlation between the numbers of total scolytids and their natural enemies that belong to 12 families and between the numbers of 5 dominant scolytids and these natural enemies were studied. In the collection, the numbers of Staphylinidae and Nitidulidae were the most abundant ones of these natural enemies. In these four areas the correlation between Staphylinidae and total scolytids is the most significant one (r = 0.73). Among 5 dominant scolytids, the correlations between H. eruditus and Nitidulidae is the most significant one (r = 0.87) and between X. affinis and Cleridae (r = 0.88) are the most two significant ones. In the pure pine forest the species richness of beetles and scolytids are 5.04 and 5.1, respectively, and the Simpson’s indices are 0.62 and 0.72, respectively. These data might be the good reference for the study on ecological conservation.

並列關鍵字

scolytid ； Lindgren multiple funnel traps ； enemy ； biodiversity

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