补充非寄主源食物显著提高万氏潜蝇姬小蜂孤雌产雌品系对美洲斑潜蝇的控害潜力

【目的】万氏潜蝇姬小蜂Diglyphus wani是潜叶蝇类害虫的重要寄生蜂，可以孤雌产雌生殖，仅产生雌性后代，具有潜在的生防应用价值。该寄生蜂为寄主取食型寄生蜂，自然条件下不仅可取食非寄主源食物，也可直接取食寄主幼虫。本研究旨在探究补充非寄主源食物对其生防效果的影响，从而有效指导其大规模饲养和田间应用。【方法】以万氏潜蝇姬小蜂的孤雌产雌品系为对象，在室内持续恒温25℃条件下，以2龄末至3龄初美洲斑潜蝇Liriomyza sativae幼虫为寄主，比较提供3种营养源食物(仅提供寄主、寄主+20%葡萄糖水、寄主+20%蜂蜜水)时万氏潜蝇姬小蜂成虫的控害潜力的差异。【结果】与仅提供寄主的处理相比，补充非寄主食物20%葡萄糖水和20%蜂蜜水均能显著提高万氏潜蝇姬小蜂的成虫寿命(分别为2.4和2.1倍)、寄生致死寄主数(分别为3.2和2.9倍)、取食致死寄主数(分别为2.7和2.2倍)和总致死寄主数(分别为2.8和2.4倍)；与仅提供寄主和补充非寄主食物20%蜂蜜水的相比，补充提供非寄主食物20%葡萄糖水能显著增强该蜂的叮蛰致死寄主数，但补充提供20%蜂蜜水与仅提供寄主处理的叮蛰致死寄主数之间差异不显著；补充提供20%葡萄糖水和20%蜂蜜水均显著增强万氏潜蝇姬小蜂的日均寄生致死寄主数和日均总致死寄主数，但不影响日均取食致死寄主数和日均叮蛰致死寄主数；且补充提供20%葡萄糖水和20%蜂蜜水两个处理间寄生蜂对美洲斑潜蝇的总致死寄主数无显著差异。3种食物源条件下，万氏潜蝇姬小蜂日均总致死寄主数在17头以上，而非繁殖型致死(寄生蜂叮蛰和取食)数占总致死寄主数比例最高。此外，在3种食物源条件下，寄生蜂的取食致死寄主数与寄生致死寄主数、成蜂寿命、总致死寄主数均显著正相关。【结论】万氏潜蝇姬小蜂可以通过寄主取食维持寿命、促进繁殖以及加强控害能力。补充非寄主源食物可以进一步延长该蜂的寿命并增强其控害能力。因此，其孤雌产雌品系有潜力成为防控美洲斑潜蝇的生防作用物，本研究结果可为万氏潜蝇姬小蜂孤雌产雌品系的室内饲养和田间释放应用提供依据和指导。

Supplementary non-host food sources significantly enhance the biocontrol potential of the thelytokous strain ofDiglyphuswani(Hymenoptera: Eulophidae) against Liriomyza sativae (Diptera: Agromyzidae)

【Aim】Diglyphus wani is regard as an important biological agent of agromyzid leafminers. It could be produced by thelytoky so that all offspring are female. This is valuable for biocontrol applications. As a host-feeding parasitoid, D. wani could feed on both non-host food and host larvae in fields. In this study, the aim is to explore the effects of supplement of non-host food on biocontrol potential of thelytokous D. wani, which could provide an insight into mass rearing and biocontrol of D. wani.【Methods】The thelytokous strain of D. wani was chosen to be our study species. The late 2nd to early 3rd instar larvae of Liriomyza sativae were provided as hosts for D. wani at the constant temperature of 25℃ in the laboratory. Differences of biocontrol potential of D. wani were compared by providing three types of food ［only hosts provided (H), hosts complemented with 20% glucose solution (HGS) and hosts complemented with 20% honey solution (HHS), respectively］. 【Results】Compared with treatment of H, supplying HGS and HHS significantly increased the adult longevity of D. wani (2.4 and 2.1 fold, respectively), the number of parasitism events (3.2 and 2.9 fold, respectively), the number of host-feeding events (2.7 and 2.2 fold, respectively), and the total number of host-killingevents (2.8 and 2.4 fold, respectively). Supplying HGS significantly increased the number of host-stinging events as compared with supplying H and HHS, respectively. However, there was no significant difference in the number of host-stinging events between supply of H and HHS. Besides, both supply of HGS and HHS significantly increased the daily number of parasitism events and daily total number of host-killing events, however, both treatments did not alter daily number of host-feeding events and daily number of host-stinging events yet. Moreover, no significant difference was found in the total number of host-killing eventsbetween supply of HGS and HHS. When D. wani was provided with the three types of food, the average daily total number of host-killing events was more than 17 hosts and the non-reproductive host-killing events (number of host stinging events and host-feeding events) accounted for the largest proportion. In addition, when D. wani was provided with the three types of food, the number of host-feeding events showed significantly positive correlations with the number of parasitism events, longevity of parasitoid, and total number of host-killing events. 【Conclusion】D. wani can increase its longevity, enlarge its fecundity and further enhance the host-killing ability through host feeding. Supplementary non-host food sources can further prolong the longevity and improve the host-killing ability of D. wani. Therefore, its thelytokous strain is a promising and potential biocontrol agent against L. sativae. This study could provide guidance for the indoor rearing and field release and application of this parasitoid.