Reproductive behaviour of <i>tetrastichus brontispae</i> ferrière (Hymenoptera: Eulophidae)

<i>Tetrastichus brontispae</i> Ferrière (Hymenoptera: Eulophidae) is an important pupae parasitoid of <i>Brontispa longissima</i> (Gestro) (Coleoptera: Chrysomelidae). This study observed the adult reproductive behaviour of <i>T. brontispae</i>, including emergence, courtship, mating, and oviposition when it develops in pupae of <i>B. longissima</i>. Our results showed that the peak emergence time of parasitoids was within the first 2 h after the first parasitoid emerged. Most host pupae had one or two emergence holes mainly on the third to sixth abdominal segments. The average number of emerged adults was 23.51 ± 9.08. Once it leaves the host pupa, the courtship and mating behaviour of <i>T. brontispae</i> were observed within 1–2 min after a male meets a female, and the mating process was usually short. Every segment of host pupa could be parasitised except the first and the last segments. The duration of oviposition was 16–20 min. The number of emerged adults had nothing to do with the duration of oviposition. Females and males were capable to mate more than once in their lifetime, and antennae appeared to be an important communication tool during their courtship behaviour. When multiple pairs of adults were together, the obvious competition was observed between males. When ovipositing, the female will choose to parasitise among multiple pupae. This paper introduces the adult behaviour of <i>T</i>. <i>brontispae</i>, may help updating the previous data and providing more comprehensive understanding for other scholars.椰甲截脉姬小蜂（*Tetrastichus brontispae*）Ferrière（膜翅目 (Hymenoptera)：姬小蜂科 (Eulophidae)）是椰心叶甲（*Brontispa longissima*）（Gestro）（鞘翅目 (Coleoptera)：叶甲科 (Chrysomelidae)）的重要蛹寄生性天敌。本研究观察了该寄生蜂在椰心叶甲蛹体内发育时的成虫繁殖行为，包括羽化、求偶、交配与产卵过程。研究结果显示，寄生蜂的羽化高峰集中在首头寄生蜂羽化后的2小时内；多数寄主蛹仅具1至2个羽化孔，且羽化孔主要分布于腹部第3至第6体节；成虫平均羽化量为23.51±9.08头。寄生蜂脱离寄主蛹后，雄蜂与雌蜂相遇后的1~2分钟内即可观测到求偶与交配行为，且交配过程通常较为短暂；除寄主蛹的首尾两节外，其余各体节均可被寄生；产卵持续时长为16~20分钟，成虫羽化数量与产卵时长无显著相关性。雌雄成虫一生均可多次交配，触角在其求偶行为中是重要的通讯工具；当多对成虫共存时，可观察到雄虫间存在明显的竞争行为；产卵时雌蜂会在多个寄主蛹之间选择适宜个体进行寄生。本研究阐明了椰甲截脉姬小蜂的成虫行为特征，可为更新既往研究数据、为其他学者提供更全面的认知参考。