不同配對條件對外米綴蛾（Corcyra cephalonica (Stainton)）交尾次數的影響

目前許多外米綴蛾（Corcyra cephalonica (Stainton)）相關研究著重於其作為害蟲天敵代用寄主的應用，本試驗以碎粒糙米將外米綴蛾幼蟲飼養於30±1℃，70±5%RH，12L:12D（每日6:00開燈，18:00關燈）的恆溫恆濕生長箱中，調查在不同的配對條件如配對時間、配對性比、配對密度對交尾次數的影響，以提供生物防治繁殖代用寄主的參考資料。結果得知雌、雄蛾皆在羽化當晚即可完成交尾和產卵；一對外米綴蛾在配對一夜和一日時，以交尾1次居多，而配對一生時的平均交尾次數為2.3次；供試蛾的交尾率及交尾次數大致皆隨配對時間之增加而增加。一隻雄蛾分別配對1至7隻雌蛾時，在24小時內，隨著雌蛾數增多其交尾次數增加，最多可與4隻雌蛾交尾，然而雌蛾交尾率隨雌：雄性比增加而顯著降低。一隻雌蛾分別配對1至7隻雄蛾時，在24小時內，雌蛾交尾次數隨配對雄蛾數之增加而增加，最多可達5次之多，但雄蛾交尾率隨雄：雌性比之增加而顯著降低。以1至7對成蛾不同配對密度配對時，7種配對密度下的平均交尾次數均約為1次，但交尾率隨配對密度增加而降低，這可能是因為當密度增加時，同性個體間產生交尾競爭所致。不同配對性比和密度試驗的結果顯示，雌、雄蛾在一日配對期間皆可和同一配偶多次交尾。

關鍵字

外米綴蛾； Corcyra cephalonica（Stainton）；交尾次數；交尾率；配對條件

並列摘要

Many recent studies on the rice moth Corcyra cephalonica (Stainton) have been addressed on its application as alternative host of pest natural enemies. In this study, C. cephalonica larvae were reared on crushed brown rice in a growth chamber at 30±1℃, 70±5% RH, with a 12L:12D photoperiod (The light was turned on at 6:00 and was off at 18:00). The influences on mating times of the rice moth by the different pairing conditions such as paired period, sex ratio, and paired density were investigated. This study could provide information for mass rearing of C. cephalonica as alternative host of pest natural enemies. The results were summarized as follows: The newly emerged moths could immediately mate and lay eggs. When a pair of the rice moths were confined together for a period of one night or one day, most of them mated only once, although others might mate twice or more. However, they mated an average of 2.3 times if paired together in the entire life. The mating rate and mating times both increased with the paired durations. When one male was paired together with one to seven females for one day, male mating times increased with the female numbers, and a male at most could mate with 4 females. However, the female mating rates decreased significantly with increasing ♀:♂ sex ratios. When one female was paired with one to seven males, female mating times increased with the male numbers, and at most could reach 5 times. Nevertheless, the mating rate of male decreased significantly with increasing ♂:♀ sex ratios. When one to seven pairs of the rice moths were confined together in the different paired densities. They mated once in average, and the mating rate decreased with increasing paired density. This might be resulted from the mating competitions among the individuals of the same sex. The study showed that the male and female rich moth within a one-day paired period could mate multiple times with the same mates.