液体植物保护膜防治瓜实蝇的效果评价

【背景】瓜实蝇是一种重要的世界性检疫害虫,广泛分布在我国的热带、亚热带地区。在室内和田间测定了液体植物保护膜对瓜实蝇的控制效能,并初步探索了该保护膜的作用方式,以期为瓜实蝇的绿色防控提供一定的技术支撑。【方法】测定了应用保护膜后瓜实蝇的产卵、存活以及对苦瓜的为害率。【结果】保护膜显著影响了瓜实蝇产卵、存活以及选择性。随着保护膜浓度的升高,瓜实蝇的存活率和在供试苦瓜段上的产卵量逐渐下降,但300和400倍保护膜之间的差异不显著。当浓度达到400倍时产卵量最低,为0.33粒,死亡率最高,约为50%;室内研究发现保护膜可持续影响瓜实蝇产卵5 d;此外,通过将保护膜应用在损伤的苦瓜上,发现保护膜并没有抑制瓜实蝇产卵。在田间,研究发现苦瓜的果长影响了保护膜的应用效能,2种果长的苦瓜应用保护膜后12~14 cm苦瓜的被害率显著低于6~8 cm苦瓜的被害率。【结论与意义】400倍的植物液体保护膜是防治瓜实蝇的最佳浓度,应用时间建议每4 d一次。保护膜最合适的应用时期为果长发育至12~14 cm时,即生长后期。施用保护膜时一定均匀,且在寄主果实受到损伤时不宜喷施保护膜。

Effect evaluation of liquid plant protection film in controlling Bactrocera cucurbitae

[Background] The melon fly Bactrocera cucurbitae, which is an important quarantine pest worldwide, has distributed in tropical and subtropical region in China. We evaluated the control efficiency of liquid plant protection film on B. cucurbitae in laboratory and field. From these preliminary results, we explored the mode of action of protection film can provide technical support for control of B. cucurbitae. [Method] The oviposition and survival of B. cucurbitae and damage rate of Momordica charantia were evaluated after spraying the protection film of different doses. [Result] The results showed that the protection film significantly affected the oviposition, survival and selectivity of B. cucurbitae. The fecundity and survival of B. cucurbitae decreased with the increase of the application rate of protection film. There were no significant differences between solutions concentrated at 300× and 400×. The lowest fecundity (0.33 egg) and highest mortality (50%) were observed at solution concentrated 400×. The data also indicated that the protection film could persistently suppress the oviposition of B. cucurbitae for five days. The protection film did not significantly suppress the fecundity of B. cucurbitae on injured bitter gourd treated with the protection film. In the field, the length of bitter gourd has effect on the control. The damage rates of 12~14 cm gourd were lower than those of 6~8 cm gourd after spraying the protection film. [Conclusion and significance] Based on these results, protection film at a 400×concentration was the optimum application concentration for control of B. cucurbitae, once every four days. The optimum application period was during the late gourd development i.e. at length of 12~14 cm. The protection film should be applied evenly on gourds. The injured host fruits were not suitable for applying the protection film.