Parasitoids of Insect Pests Feeding on Scaevola taccada (Goodeniaceae) from Yongxing Island in South China Sea

<i>Scaevola taccada</i> (Goodeniaceae) is an important evergreen coastal plant on islands in the South China Sea, which shows excellent tolerance for salty and drought conditions. Nevertheless, the growth of <i>S. taccada</i> populations on these islands in the South China Sea has been threatened by a few serious insect pests. However, we know little about the biology of these pests. In this study, we surveyed and identified the parasitoids of two main pests (<i>Herpetogramma submarginale</i> (Swinhoe, 1901) and <i>Ophiomyia scaevolana</i> Shiao and Wu, 1996) of <i>S. taccada</i> communities on Yongxing Island in the South China Sea, with the aim to assess their potential in biological control. <i>Dolichogenidea stantoni</i> (Ashmead, 1904) is a gregarious endoparasitoid of the larva of <i>H. submarginale</i> and contributes an average 48.9% parasitism rate on <i>H. submarginale</i>. <i>Opius biroi,</i> Fischer, 1960 and <i>Euderus albitarsis</i> (Zetterstedt, 1838) are both solitary endoparasitoids of the larva of <i>O. scaevolana</i>, with a respective 5.8% and 64.4% parasitism rate on <i>O. scaevolana</i>. We summarize the species diagnosis, biology, and distribution of the three parasitoid species. The potential of these parasitoids used in biological control is also discussed.