遗常室茧蜂的生物学特性及其对苜蓿盲蝽的生物防治潜力 英文标题:Biology of the Peristenus Relictusand Its Potential as a Biological Control Agent Ofthe Alfalfa Plant Bug， Adelphocoris Lineolatus

遗常室茧蜂Peristenus relictus Ruthe (Hymenoptera:Braconidae)是一种单寄生、容性寄生蜂，其寄主范围较广，发生于中国长江和黄河流域的一种本地内寄生性寄生蜂。这种卵育型的若虫寄生蜂可孤雌生殖，与红颈常室茧蜂同为一个类群中的主要寄生蜂，寄生在造成中国多种农作物经济损失的重要害虫盲蝽体内。尽管在过去10年中，中国种植Bt棉花获得了巨大的收益，但大面积种植转Bt基因棉花同时导致了次要害虫的爆发，特别是在农作物上急剧减低了广谱性叶面杀虫剂的使用，致使多种盲蝽爆发发生。因此，该寄生蜂已作为一种生防天敌，通过大量释放来控制中国Bt棉花种植区中种群数量迅速增长的多种盲蝽。该寄生蜂已广泛分布于世界各地，并已知该蜂的生态学、发育和繁殖生物学。然而，为探讨大量释放该蜂的生物防治潜力，仍有一些生物学特性亟待研究。为构建一种高效益的大量繁殖体系，了解该蜂种群动态并根据盲蝽的发生情况有效地进行田间释放，在室内进行了评价其对苜蓿盲蝽的生物防治潜力。本博士论文研究了盲蝽的天敌——遗常室茧蜂以下3个方面的生物学：1)遗常室茧蜂在不同寄主和寄生蜂密度下的功能反应、种内干扰和性比分配模式遗常室茧蜂对苜蓿盲蝽功能反应属于Holling Ⅱ，其寄生率随着苜蓿盲蝽的密度增加而呈显著减少。即寄主密度和寄生率为反比。结果表明，寄生数随着寄主密度的增加而增加，直到接近该蜂的最大生殖潜能。种内干扰结果表明，随着若虫与寄生蜂的比例的降低(寄主若虫保持80头)，显著减少被寄生的寄主数，当处理为1头寄生蜂时，单头蜂产生的子代数是处理为16头寄生蜂时的20-30倍。干扰常数为1.20，存在着强烈的干扰作用。减少寄主比例并增加寄生蜂种个体数，明显增加了寄生蜂本身和种内其它个体的过寄生率，其后代雄性比例增加，这说明了寄生蜂之间存在强烈的种内竞争。寄主和寄生蜂密度之间的相互作用所反映的性比，充分支持了本地雄蜂竞争(LMC)理论假设。2)遗常室茧蜂对苜蓿盲蝽不同寄主龄期的偏好性以及发育和繁殖适应性寄主偏好及其适应性研究表明，该蜂主要偏好于1-3龄的苜蓿盲蝽若虫。在非选择性试验中，对1-2龄若虫的最高寄生率89.26%-91.09%，在选择性试验中为93.08-93.21%。然而，被寄生的1龄若虫的死亡率高于其它龄期被寄生若虫。重寄生率随着寄主龄期增加而减少。尽管1-4龄寄主若虫都能够被寄生，但2龄寄主若虫是最佳的寄生龄期，因为它产生的后代数量最多且雌性偏多。其次是3龄若虫，是寄主适应性的第二选择。5龄若虫被寄生后没有产出寄生蜂后代。寄主龄期越大寄生蜂羽化越快。3)不同恒温条件下寄生于苜蓿盲蝽的遗常室茧蜂的繁殖生物学温度是寄生蜂最关键的非生物影响因子之一，温度对寄生蜂的生殖力、产卵期、寿命、日产卵量以及总产卵量都有显著的影响。寄生蜂的寿命随着温度从15℃上升到30℃而缩短。雌蜂平均寿命从15℃时的28.40±1.29天下降到30℃时的7.20+0.66天，然而日平均产卵量在25℃时最高，为41.51±6.05粒，15℃时最低，为11.47+3.31粒。生殖寿命在20℃时最长，能产卵18.60±1.86天。20℃下产卵能力最高，为675.4±56.78粒卵，其次为25℃，为530.60±34.50粒卵。同时，寄生蜂的总寄生数与和产卵量趋势相同，20℃时寄生数591.20±2.87头若虫，15℃时的寄生数为217.80±3.61头若虫。本论文的结果表明遗常室茧蜂可作为防治在国Bt棉田中盲蝽的一种有效生物防治天敌。为了达到在Bt棉田上释放大量的寄生蜂的目的，大规模群繁中最佳的寄生蜂与寄主若虫比例应为1：80，并且最佳饲养温度为20℃。目标害虫2龄若虫时，是田间释放遗常室茧蜂最佳龄期。

Peristenus relictus Ruthe (Hymenoptera: Braconidae) is a solitary koinobiont endoparasitoid with a broad host range. It is a native endoparasitoid distributed in the Yangtze River and Yellow River basins of China. This pro-ovigenic nymphal parasitoid is capable of parthenogenesis, and along with Peristenus rubicollis, it is a major parasitoid in its taxon group, which parasitizes various important mirid bug pests that cause significant economic losses to multiple crops in China.
Although Bt cotton cultivation has brought substantial economic benefits to China over the past decade, large-scale planting of transgenic Bt cotton has also led to outbreaks of secondary pests. Specifically, the sharp reduction in the use of broad-spectrum foliar insecticides on crops has resulted in population outbreaks of multiple mirid bug species. Therefore, P. relictus has been developed as a biological control agent, and mass releases are conducted to suppress the rapidly increasing populations of various mirid bugs in Bt cotton-growing regions of China.
This parasitoid has a worldwide distribution, and its ecology, development, and reproductive biology have been well documented. However, several biological traits remain to be investigated to fully evaluate the biocontrol potential of mass-released individuals of this species. To establish a cost-effective mass-rearing system, understand the population dynamics of P. relictus, and conduct effective field releases based on the occurrence of mirid bugs, laboratory experiments were conducted to assess the biocontrol potential of P. relictus against the alfalfa plant bug, Adelphocoris suturalis.
This doctoral dissertation investigated three key biological aspects of P. relictus, a natural enemy of mirid bugs:
1) Functional response, intraspecific interference, and sex ratio allocation patterns of P. relictus under different host and parasitoid densities
The functional response of P. relictus to A. suturalis nymphs was determined to be Holling Type II. Parasitism rate decreased significantly with increasing host density, indicating an inverse relationship between host density and parasitism rate. The results showed that the number of parasitized hosts increased with rising host density until approaching the maximum reproductive potential of the parasitoid. Intraspecific interference experiments revealed that as the ratio of nymphs to parasitoids decreased (with a fixed 80 host nymphs), the number of parasitized hosts decreased significantly. When the treatment had 1 parasitoid, the number of offspring produced per individual was 20-30 times higher than that of treatments with 16 parasitoids. The interference constant was 1.20, indicating strong intraspecific interference. Reducing the host ratio and increasing the number of parasitoid individuals significantly increased the superparasitism rate of both the parasitoid itself and other conspecific individuals, as well as the proportion of male offspring. This demonstrates intense intraspecific competition among the parasitoids. The sex ratio reflected by the interaction between host and parasitoid densities fully supports the Local Mate Competition (LMC) theoretical hypothesis.
2) Host stage preference, developmental and reproductive adaptability of P. relictus to A. suturalis
Host preference and adaptability studies showed that this parasitoid primarily prefers 1st to 3rd instar nymphs of A. suturalis. In non-choice tests, the highest parasitism rates on 1st to 2nd instar nymphs were 89.26%–91.09%, while in choice tests, the rates were 93.08%–93.21%. However, the mortality rate of parasitized 1st instar nymphs was higher than that of parasitized nymphs of other instars. Superparasitism rate decreased with increasing host instar. Although 1st to 4th instar host nymphs could be parasitized, 2nd instar host nymphs were the optimal parasitism stage, as they yielded the highest number of offspring with a female-biased sex ratio. The 3rd instar nymphs were the second-best choice for host adaptability. No parasitoid offspring emerged from parasitized 5th instar nymphs. The emergence time of parasitoid offspring accelerated with increasing host instar.
3) Reproductive biology of P. relictus parasitizing A. suturalis nymphs under different constant temperature conditions
Temperature is one of the most critical abiotic factors affecting parasitoids, and it has significant impacts on their fecundity, oviposition period, longevity, daily oviposition rate, and total oviposition amount. The longevity of the parasitoid decreased as temperature rose from 15°C to 30°C. The average longevity of female wasps decreased from 28.40 ± 1.29 days at 15°C to 7.20 ± 0.66 days at 30°C. However, the daily average oviposition rate was highest at 25°C, reaching 41.51 ± 6.05 eggs, and lowest at 15°C, at 11.47 ± 3.31 eggs. The reproductive lifespan was longest at 20°C, with an oviposition period of 18.60 ± 1.86 days. The oviposition capacity was highest at 20°C, with 675.4 ± 56.78 eggs, followed by 25°C with 530.60 ± 34.50 eggs. Meanwhile, the total number of parasitized hosts showed the same trend as oviposition amount: 591.20 ± 2.87 nymphs at 20°C, and 217.80 ± 3.61 nymphs at 15°C.
The results of this dissertation indicate that P. relictus can serve as an effective biological control agent for suppressing mirid bug populations in Bt cotton fields of China. To achieve large-scale parasitoid releases in Bt cotton fields, the optimal ratio of parasitoids to host nymphs for mass rearing should be 1:80, and the optimal rearing temperature is 20°C. The optimal field release stage of P. relictus is when the target pest is at the 2nd instar nymph stage.

搜集汇总

背景与挑战

背景概述

该数据集聚焦于遗常室茧蜂的生物学特性及其对苜蓿盲蝽的生物防治潜力研究。数据集详细探讨了该寄生蜂的功能反应、寄主偏好和温度适应性，旨在评估其作为生物防治天敌的效果，以控制Bt棉花种植区盲蝽害虫的爆发。研究结论建议最佳饲养条件为20℃和1:80的寄生蜂与寄主比例，并推荐在目标害虫2龄若虫期进行田间释放，以实现高效防治。