Abstract The leafminer, Liriomyza bryoniae Kalt. (Diptera：Agromyzidae) is an important insect pest of muskmelon in Taiwan. The adults inflict injury to the plant by puncturing the leaf surface with their ovipositors and lapping juice from the punctures, thereby resulting in numerous white spots remaining on the leaves. Meanwhile the larvae fed inside the leaf tissues and created a number of serpentine mines. Heavy stippling and mining could kill seedlings or else slow the growth of plants. Under the growth chamber with temperature at 15、20、25 and 30℃ and 14-hr. light conditions, the feeding activity of adult was highest at 25℃. Wherein, a female could create about 820 feeding punctures daily and 4032 in total. The feeding punctures declined remarkably at temperatures higher or lower than 25℃. On the other hand, the leaf area mined by a larva was about 515 mm2 which was singnificantly larger than those mined at other tempera-tures. In field conditions, the damage of the leafminer increased with the growth of muskmelon. It could cause yield reduuction more than 60﹪. However, the yield and quality of fruit were not affected significantly when the damage did not exceed grade 2(ex. 2-3 miners or mines per leaf and the number of damaged leaves did not exceed 20% of total leaves). Moreover, the yield reduction in plants injured before fruit setting stage was significantly higher than that injured during the fruit growing stage. As a control program initiated from seedling stage, the yidld and quality of fruit between the plants protected from damage of the leafminer up to mid-fruiting stage and those protected up to the mature stage were not different significantly, indicating that control of the pest after mid-fruiting stage was not required.
摘要 番茄斑潛蠅之成蟲及幼蟲均可在洋香瓜葉片取食為害，成蟲以產卵管戳破葉面組織再以口器吮吸汁液，殘留0.4×0.5mm左右之橢圓形白色斑痕；而幼蟲則潛食於葉片組織中，形成蜿蜒曲折的白色食痕，嚴重被害時，導致葉片枯萎。在15、20、25及30℃，光照14小時之恆溫箱中，分別觀察成蟲之取食頻度及幼蟲之潛食面積，結果顯示雌成蟲在25℃之取食頻度最高，每日平均可形成食痕達820個，一生可形成4032個食痕，溫度升高或下降食痕數減少，尤以低溫時其取食頻度顯著降低。幼蟲潛食葉片面積以於20℃最大，達515mm2左右，顯著地較在其他溫度下之取食面積為大。在30℃之取食面積最小，僅為20℃之61﹪。在田間，洋香瓜自苗期即可遭受番茄斑潛蠅之為害，其為害狀隨植株生長而增重，在無防治情況下可導致60﹪以上之產量損失。然而至生育後期，葉片被害度不超過2級，即具2至3條幼蟲食痕之葉片不超過全數之20﹪的情況下，對瓜果產量及品質即不致有明顯影響。洋香瓜植株在苗期至著果期遭受斑潛蠅為害對瓜果產量之影響較著果以後始受害者為明顯，但自苗期開始防治斑潛蠅至果實發育中期與防治至果實成熟期者，瓜果之產量與品質並無顯著差異，顯示在果實發育中期以後即無需再噴藥防治。
| Key words: Lieiomyza bryoniae, muskmelon, damage, yield reduction. | | 關鍵詞: 番茄斑潛蠅、洋香瓜、為害、產量損失。 |
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