甜菜夜蛾（鱗翅目：夜蛾科）在茄葉與人工飼料上之生活史與族群表現

The life history and population performance of Spodoptera exigua (Lepidoptera: Noctuidae) on eggplant and artificial diet

甜菜夜蛾為世界重要多食性害蟲，寄主廣泛，可危害包括茄科、葫蘆科、十字花科等多種重要經濟作物，育苗場茄砧之種植亦受此蟲之嚴重危害。本試驗以甜菜夜蛾在茄葉與人工飼料上進行生活史之探討，並分析其族群表現。在茄葉與人工飼料下，卵至幼蟲之發育時間分別需14.03日與13.97日，蛹期為5.86日，雌雄蟲之壽命介於8.31～11.57日之間。人工飼料飼育之存活率顯著高於以茄葉飼育。茄葉與人工飼料飼育之產卵量分別為656.7與563.5 eggs/female。在族群介量的表現上，不同食物飼育下，其淨繁殖率（R_0）、內在增殖率（r）、終極增殖率（λ）與平均世代時間（T）均無顯著差異，以茄葉與人工飼料飼育之內在增殖率分別為0.2496 day^(-1)與0.2451 day^(-1)。此研究提供甜菜夜蛾於茄葉與人工飼料下之基礎生態，可供日後此蟲在育苗場防治策略研擬及人工大量飼育之參考。

The beet armyworm, Spodoptera exigua, is a major polyphagous pest distributed worldwide with a wide range of hosts including economic crops in Solanaceae, Cucurbitaceae and Brassicaceae. Eggplant rootstocks in nurseries also been damaged by the beet armyworms. To gain a better insight into its bionomics and ecology, the life history and population performance of S. exigua on eggplant and artificial diet were determined and analyzed. Egg to larva developmental time was 14.03 days and 13.97 days on eggplant and artificial diet, respectively, while the pupal stage lasted an averge of 5.86 days. The mean longevity of all was between 8.31 and 11.57 days. In addition, the survival rate of S. exigua on artificial diet was higher than that on eggplant significantly. Mean fecundity was 656.69 eggs per female on eggplant and 563.45 eggs per female on artificial diet, respectively. There were no significant differences observed in net reproductive rate (R_0), intrinsic rate of increase (r), finite rate of increase (λ) and mean generation time (T) between eggplant and artificial diet. Intrinsic rate of increase (r) was 0.2496 day^(-1) and 0.2451 day^(-1) on eggplant and artificial diet, respectively. This study could provide basic information for pest management strategies at nurseries and mass rearing of S. exigua in the future.