低溫保存對卵寄生蜂平腹小蜂(Anastatus japonicus)（膜翅目：旋小蜂科）之影響

Effects of cold storage on the egg parasitoids (Anastatus japonicus) (Hymenoptera: Eupelmidae)

荔枝椿象 (Tessaratoma papillosa (Drury)) 為近年來台灣危害嚴重之入侵害蟲，其在台灣之危害植物包括重要經濟之果樹龍眼、荔枝及常見公園、校園栽種樹種台灣欒樹和無患子。平腹小蜂 (Anastatus japonicus Ashmead) 為臺灣田間荔枝椿象卵期常見之卵寄生蜂，是目前荔枝椿象綜合管理策略中生物防治重要的一環。然而一年一代的荔枝椿象無法大量生產天敵飼養所需的卵量，本研究針對使用蓖麻蠶卵作為平腹小蜂大量飼養替代寄主，以低溫12°C 保存處理對平腹小蜂羽化及其子代之寄生能力的影響進行探討。結果顯示平腹小蜂以0-3日發育日數，最適合進行低溫12°C 保存處理，可保存至5個月與對照組之羽化率64.8% 間沒有顯著差異，但至第6個月則有顯著降低。而經低溫保存1-5個月後所羽化的平腹小蜂雌蜂，其寄生能力沒有顯著差異，於7至13日齡連續寄生7日，羽化的平腹小蜂子代數量最低皆有59.8隻以上，而且雌蜂比率有71% 以上。本試驗結果可實際應用於平腹小蜂量產技術，提前進行寄生作業，以增加平腹小蜂數量，並可適時提供田間釋放作業之所需，有利於進行荔枝椿象之生物防治。

Anastatus japonicus is a common egg parasitoid of Tessaratoma papillosa in Taiwan. In order to establish a mass rearing program for the parasitoid, this study examined the effects of low temperature (12 °C) storage on the survival of A. japonicus in the eggs of its factitious host, Samia cynthia. The results showed that the most suitable stage for the cold storage treatment was during the first five days of immature development. The emergence rates of parasitized eggs stored for up to 5 months were not significantly different from the untreated control group (64.8%). However, there was a significant reduction in the emergence rate for the eggs stored for 6 months. In addition, there was no significant difference in the parasitism rates among female A. japonicus wasps that emerged from 1-5 months of cold storage. The minimum number of progenies was 59.8 from the 7 to 13-day-old wasps with more than 71% of the progeny being female. The results of this study can be applied to the mass rearing of A. japonicus. Using the cold storage technique, the production of the biocontrol agent can start before T. papillosa becomes active in the spring. It provides the tool to achieve timely field release, which is essential to assure the effectiveness of T. papillosa biological control.