Host utilization and taxonomy of a new pest, Anselmella miltoni Girault (Hymenoptera: Eulophidae), and its parasitoid wasps on wax apple

• Main Authors: Chuan-Cheng Chung, 鍾權承
• Other Authors: Man-Miao Yang
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/52428034365541759277

碩士 === 國立中興大學 === 昆蟲學系所 === 105 === Anselmella miltoni Girault is an important pest on wax apple (Syzygium samarangense) in recent years, which cause quarantine problem during export. This wasp induces gall inside the fruit of wax apple and devaluate the commodity when emergent adult tunnel through the fruit. Beside wax apple, A. miltoni uses another congeneric plant, S. jambos (rose apple), as a host in Taiwan. Rose apple is a non-economic plant and, therefore, ignored easily during the control of A. miltoni. Up to date, little information about A. miltoni on rose apple is known. Due to the above reason, this research conducted survey on its host range, distribution, gall development and its parasitoid wasps. There were six parts. (1) I surveyed the occurrence of A. miltoni on wax apple in Taiwan, and searched for similar gall-making wasps on other congeneric plants. The result shows that there is congeneric wasp in seed part of rose apple (S. jambos). (2) Morphological and molecular characters were used to compare the Anselmella wasps on wax apple and rose apple. As a result, both gall-making wasps on wax apple and rose apple are A. miltoni. (3) Developmental stages of A. miltoni were recorded through dissecting fruits of rose apple and the correlation of growth between A. miltoni and fruit were established. The result was compared with the similar research about wax apple. (4) Two wasps, Aprostocetus sp. and Megastigmus sp., found inside the galls of A. miltoni on rose apple were confirmed to be parasitoid wasps. I further investigated the timing, depth, and percentage of parasitoid. According to the result, parasitoid wasps that can only live on rose apple are not suitable to directly control the A. miltoni on wax apple. However, through suppressing the population of A. miltoni on rose apple, it may decrease pest source to lessen the damage on wax apple indirectly and, henceforth, may become a feasible and ecofriendly control method. (5) I set up predictive occurrence model of A. miltoni by MaxEnt. The area with high probability of occurrence in Taiwan should be the main concern of pest control, and countries with lower chance of occurrence in the world are candidate nations for the trade of wax apple. (6) Morphology of A. miltoni and its two parasitoid wasps were described and was compared with literatures. Host use is an important information when we set up the pest control strategy, no matter whether the host plant is an economic crop or not. In this research, we made sure that A. miltoni can induce gall on rose apple, and it could be a pest source of wax apple. Control of pests on non-economic important host may be an effective mean in interrupting pest source. To decrease the infection rate on wax apple, we should manage both wax apple and rose apple when set up pest control strategy. Although parasitoid wasps of A. miltoni only found in the galls of rose apple, future researches may develop to decrease infection rate on wax apple indirectly via suppression the possible infection source from rose apple.