【作者】 王勇；

【导师】 臧连生； 侯洋旸；

【作者基本信息】 吉林农业大学 ， 生物防治， 2021， 硕士

【摘要】 赤眼蜂在绿色防控中起着至关重要的作用,目前通过工厂化繁殖赤眼蜂可以有效控制的鳞翅目害虫已有1200多种。而赤眼蜂的生殖力能够直接影响到其对靶标害虫的防控能力。因此,了解赤眼蜂面对不同环境时体内卵子自我调控的规律,进而明确此规律对赤眼蜂生殖力的影响,能够有助于赤眼蜂在防控害虫中高效低成本的应用。本研究拟通过生殖系统发育学和解剖学等方法,对比不同生态条件下,四种赤眼蜂(松毛虫赤眼蜂Trichogramma dendrolimi、螟黄赤眼蜂Trichogramma chilonis、玉米螟赤眼蜂Trichogramma ostriniae和黏虫赤眼蜂Trichogramma leucaniae)体内卵子发育情况。利用解剖等手段,掌握赤眼蜂体内卵子的形态;以生殖结构为基础,通过测定不同因素(交配、营养情况、寄主适应情况等)下,赤眼蜂寄生和抱卵量等变化,全面和系统的研究影响赤眼蜂体内卵子发育关键因素。研究主要结果如下:1.本实验通过对寄生蜂卵巢的解剖,参考已发表寄生蜂卵子分级方法,将赤眼蜂的卵子进行分为三个等级。Ⅰ级卵:卵子接近球形;Ⅱ级卵:卵子呈椭圆形,一端相对较尖,靠近基部输卵管的另一端呈钝圆形。卵子形状不饱满,卵黄填充度≥1/2卵室体积;Ⅲ级卵:与Ⅱ级卵形态相似,但卵子形状更加饱满,整个卵室充满卵黄。通过测量观察发现,四种赤眼蜂各级卵子的形态大小较为相似。2.喂食不同营养物质对赤眼蜂的卵子发育存在一定影响。本实验设定不喂食、喂食清水、蜂蜜水和果糖水四个处理,时间梯度设定4、8、12、16、20、24、48和72h。四种赤眼蜂初羽化时体内均含有一定数量成熟和未成熟卵子,并在羽化4h内体内卵子数显著增多。4h后,四种赤眼蜂体内抱卵量呈现了不同的变化趋势。松毛虫赤眼蜂,不喂食和喂食清水的处理中,体内卵子数量随时间变化较为一致,均呈现先升高后下降的趋势,羽化12h抱卵量达到最高峰。而喂食蜂蜜水和果糖水处理中,相对于前两个处理,赤眼蜂体内抱卵量显著增加。虽然体内卵子量变化趋势同样为先增加后降低,但是产卵高峰值的时间延长至20h。对于螟黄赤眼蜂,不喂食和喂食清水中,赤眼蜂体内抱卵量随时间延长并不存在显著性差异。而在取食蜂蜜和果糖处理中,与不喂食和喂食清水相比,抱卵量显著增加。另外,营养物质延长了该蜂的产卵高峰时间,24h内赤眼蜂体内怀卵量呈现逐渐增加趋势,48和72h后显著性下降。玉米螟赤眼蜂在不喂食和喂食清水的处理中,体内的抱卵量逐渐增加,而喂食蜂蜜和果糖下,抱卵量并无显著性变化。上述四个处理之间,玉米螟赤眼蜂发育12h后的抱卵量并无显著性差异。营养物质仅仅加速了玉米螟赤眼蜂体内卵子的成熟速度。黏虫赤眼蜂在上述四个处理中,体内抱卵量均无显著性变化,并且处理之间不存在显著性差异。营养物质对该蜂的抱卵量无显著性影响。3.对交配和未交配的四种赤眼蜂,不同时间段下(4h、8h、12h、16h、20h、24h)体内抱卵量比较后发现,交配行为对赤眼蜂体内的抱卵量存在显著性影响,不同种类的赤眼蜂展现不同。交配的松毛虫赤眼蜂0-24h,体内的抱卵量呈现逐渐下降的趋势,24h的抱卵量显著性最低。未交配的松毛虫赤眼蜂体内抱卵量存在略微上升趋势,但是各处理间并无显著性差异。交配的螟黄赤眼蜂抱卵量呈先升高后降低趋势,20和24h下抱卵量显著性降低。未交配的螟黄赤眼蜂体内抱卵量几乎不变,各处理之间并不存在显著性差异。交配与未交配的玉米螟赤眼蜂,随时间的延长,抱卵量逐渐增加,4h和8h处理下的抱卵量显著低于其他处理。而交配与未交配的黏虫赤眼蜂体内的卵子数量几乎无太大变化,各处理之间并无显著性差异。而对于上述四种赤眼蜂,未交配的蜂种体内的抱卵量均高于已交配的赤眼蜂体内的抱卵量。除松毛虫赤眼蜂4h、螟黄赤眼蜂20和24h以外,其他处理之间,差异均存在显著性差异。4.提供不同数量的寄主米蛾卵(20、40、80、150粒和300粒),对四种赤眼蜂六个时段下(4、8、12、16、20和24h)的寄生量、怀卵量以及总卵量(寄生量+怀卵量)进行调查发现,在所有时间段下,4种蜂赤眼蜂随提供寄主数量的增加,寄生量增加,抱卵量下降,总卵量下降。四种赤眼蜂在20、40、80、150和300粒米蛾卵上寄生24小时后的寄生量分别为,松毛虫赤眼蜂13.4、32.0、46.6、60.8和79.9粒;螟黄赤眼蜂13.5、18.4、25.4、29.3和36.0粒;玉米螟赤眼蜂10.0、16.3、36.0、36.6和44.9粒以及黏虫赤眼蜂10.3、27.6、29.5、32.4和34.3粒。设定提供300粒寄主卵下赤眼蜂的产卵量为最高产卵量,虽然大部分处理所提供的寄主卵数量(例如80、150粒)均大于最高产卵量,但赤眼蜂在这些处理下的寄生量并未达到最大产卵量。通过上述结果可知,赤眼蜂具备根据寄主数量来评估产卵量的能力。5.研究比较了四种赤眼蜂寄生不同适合度寄主时(米蛾卵、柞蚕剖腹卵和柞蚕自产卵)的寄生量、怀卵量和总卵量(寄生量+怀卵量)。四种赤眼蜂均可较好的寄生米蛾卵,其寄生量、怀卵量和总卵量随寄生时间的延长展现出的变化趋势也较为相似。具体变现为,寄生量逐渐上升,怀卵量逐渐下降,总卵量上升至平稳。在米蛾卵上,赤眼蜂的寄生量显著高于柞蚕剖腹卵和自产卵。而在上述两种寄主卵上,由于适应性的不同,四种赤眼蜂的寄生和体内卵子的发育表现出了较大的差异。松毛虫赤眼蜂和螟黄赤眼蜂能够较好的寄生柞蚕剖腹卵,两种蜂的寄生量和总卵量随寄生时间的延长逐渐增加,怀卵量逐渐下降。玉米螟赤眼蜂无法寄生柞蚕剖腹卵,其总卵量即为体内怀卵量,呈现逐渐上升的趋势,寄生8h后各时间段之间不存在显著性差异。黏虫赤眼蜂随时寄生时间的延长,能够逐渐适应柞蚕剖腹卵,表现为16h起有少量寄生,20、24h寄生量逐渐增加,其体内的怀卵量自16h起略微下降,而总卵量在16h起存在略微升高。但对于寄生柞蚕自产卵,松毛虫赤眼蜂和螟黄赤眼蜂仅能少量寄生,其余两蜂种则无法寄生。四种寄生蜂的怀卵量和总卵量表现为,各时间段下,松毛虫赤眼蜂的寄生量并无显著变化,体内的抱卵量和总卵量呈现逐渐下降的趋势。螟黄赤眼蜂怀卵量和总卵量在20和24h下存在略微下降,但各时间段并无显著性差异。玉米螟赤眼蜂总卵量即为体内怀卵量,呈现逐渐上升的趋势,寄生8h后各时间段之间不存在显著性差异。黏虫赤眼蜂体内怀卵量和总卵量随寄生时间的延长并无明显变化。结果表明,不同寄主对不同赤眼蜂的适合度存在明显差异,而不同适合度的寄主显著性影响赤眼蜂的寄生,进而影响了蜂种体内卵子的发育。更多还原

【Abstract】 Trichogramma parasitoids are the most important biological control agents of lepidopterous pests.At present,there are more than 1,200 lepidopteran pests that can be effectively controlled through mass production of Trichogramma species.The fecundity of Trichogramma can directly affect its ability to control target pests.Therefore,understanding the phenomenon of self-regulation of Trichogramma egg maturation in different environments,and then clarifying the influence of that phenomenon on their fecundity,can help Trichogramma to be used in the prevention and control of pests with high efficiency and low cost.Here in this study,we compared four Trichogramma species(i.e.,T.dendrolimi,T.chilonis,T.ostriniae and T.leucaniae)under different ecological conditions through methods such as reproductive system development and anatomy of egg development in the body.Use anatomy and other methods to grasp the morphology of Trichogramma eggs in the body;based on the reproductive structure,by measuring the changes of Trichogramma parasitism and egg holding capacity under different factors(i.e.,mating,nutritional status,host adaptation,etc.).The research on the key factors affecting the egg development of Trichogrammahas been discussed in details.The main results of the study are as follows:1.In this experiment,the ovaries of the female Trichogramma wasps were dissected,and the eggs were classified into three grades by referring to the published method of grading.Grade Ⅰ egg: The egg was nearly spherical;Grade Ⅱ egg: The egg was elliptical,one end was relatively pointed,and the other end near the base of the fallopian tube was obtuse.The egg shape was not full,and the yolk filling degree was≥ 1/2 the volume of the egg chamber;Grade Ⅲ egg:similar to the shape of the Grade Ⅱ egg,but the egg shape was more full,and the entire egg chamber was filled with yolk.Through measurement and observation,it was found that the morphology and size of the eggs of the four Trichogramma species were similar.2.Fed with different nutrient certainly affected the development of Trichogramma eggs inside the body.This experiment was set into four treatments: i.e.,did not feed wasps,wasps fed with clean water,fed with honey water and fructose water,and the time gradient setting was 4,8,12,16,20,24,48 and 72 h.The results showed that all the four Trichogramma species had a certain number of mature and immature eggs when they first emerged.The number of eggs in the body increased significantly within 4 hours of emergence.After 4 hours,the amount of eggs held by the four Trichogramma species showed different trends.For T.dendrolimi,the number of eggs in the body was more consistent with time in the treatment where T.dendrolimi wasps were kept hungry and where fed with only water.In both treatments,the number of eggs in T.dedrolimi female showed a trend where it first increased and then decreased,and the egg holding volume reached at the highest peak after 12 hours of emergence.In the treatment where wasps were fed with honey water and fructose water,compared with the previous two treatments,the amount of eggs held by Trichogramma was significantly increased.Although the changed trend of the amount of eggs in the body also increased first and then decreased,the time of peak egg laying was extended to 20 h.For T.chilonis,there was no significant difference in the amount of eggs held in the body of wasp,Trichogramma with time without fed or fed with clean water.In the treatment of honey and fructose,compared with no feeding and feeding with water,the amount of egg holding increased significantly.In addition,the nutrients prolonged the peak egg laying time of the wasp.Within 24 hours,the amount of eggs conceived in wasp was gradually increased,and it decreased significantly after 48 and 72 hours.The amount of eggs held by T.ostriniae was gradually increased in the treatment of no feeding and water feeding,but there was no significant change in the amount of eggs held by feeding honey and fructose.Among the above four treatments,there was no significant difference in the amount of eggs held by the T.ostriniae after 12 hours of development.Nutrients only accelerate the maturation of the eggs of T.ostriniae.There was no significant change in the amount of eggs held by T.leucaniae in the above four treatments,and there was no significant difference between the treatments.Nutrients have no significant effect on the amount of eggs held by the wasp.3.For the mated and unmated four Trichogramma species,after comparing the egg holding capacity in different time periods(4h,8h,12 h,16h,20 h,24h),it was found that mating behavior has a significant effect on the egg holding capacity in the body of Trichogramma.In mated T.dendrolimi 0-24 h,the amount of eggs in the body showed a gradual decline,and the amount of eggs in 24 h was the least significant.There was a slight upward trend in the amount of eggs held by the unmated T.chilonis,but there was no significant difference among the treatments.The amount of eggs held by the mated T.chilonis increased first and then decreased,and the amount of eggs held at 20 and 24 hours decreased significantly.The amount of eggs held in the unmated T.chilonis was almost unchanged,and there was no significant difference between the treatments.In mated and unmated T.ostriniae,the amount of egg holding gradually increased with time,and the amount of holding eggs under 4h and 8h treatments was significantly lower than other treatments.The number of eggs in the mated and unmated T.leucaniae hardly changed,and there was no significant difference between the treatments.For the four Trichogramma species mentioned above,the amount of eggs in the unmated wasp species was higher than the amount of eggs in the mated Trichogramma species.Except for T.dendrolimi 4h and T.chilonis 20 and 24 h,there were significant differences among other treatments.4.Provide different numbers of host rice moth eggs(20,40,80,150 and 300),parasitic amount and egg holdingandtotal eggs(parasitic amount+egg holding)of the four Trichogramma species in six time periods(4,8,12,16,20 and 24h).The investigation of the amount of eggs and the total amount of eggs(parasite amount + egg holding)found that in all time periods,with the increase of the number of provided hosts eggs,the amount of parasitism increased,and the amount of eggs held,and the total amount of eggs decreased.The number of parasitized eggs of the four Trichogramma species on 20,40,80,150 and 300 rice moth eggs for 24 hours,for T.dendrolimi were 13.4,32.0,46.6,60.8 and 79.9 eggs;for T.chilonis were13.5,18.4,25.4,29.3 and 36.0 eggs;for T.ostriniae were 10.0,16.3,36.0,36.6 and 44.9 eggs,and for T.leucaniae 10.3,27.6,29.5,32.4 and 34.3 eggs.The maximum number of eggs laid by the Trichogrammawas when were provided with 300 host eggs.Although the number of host eggs(such as 80,150)provided by most treatments is greater than the maximum number of eggs laid.The amount of parasites under these treatments did not reach the maximum egg production.From the above results,it can be seen that Trichogramma has the ability to evaluate the number of eggs laid by the number of hosts.5.The study compared the four Trichogramma species amount of parasitism,the amount of egg holding and the total amount of eggs(parasitic amount + egg holding)of four Trichogramma species when they parasitized different suitable hosts(rice moth eggs,manually-extracted unfertilized eggs of Chinese oak silkworm and naturally laid eggs by A.pernyi eggs).All four Trichogramma species can parasitize rice moth eggs well,and their parasitic amount,egg holding amount,and total egg amount show similar changes with the prolongation of parasitic time.The specific findings were that the amount of parasitism gradually increased,the amount of eggs holding gradually decreased,and the total amount of eggs rises to a stable level.On rice moth eggs,the parasitic amount of Trichogramma was significantly higher than that of manually-extracted unfertilized eggs of Chinese oak silkworm and naturally laid eggs by A.pernyi.On the above-mentioned two kinds of host eggs,due to the different adaptability,the parasitism of the four Trichogramma species and the development of the eggs in the body showed great differences.The T.dendrolimi and T.chilonis can better parasitize manually-extracted unfertilized eggs of Chinese oak silkworm.The parasitic amount and total egg amount of the two kinds of wasps gradually increase with the extension of the parasitic time,and the amount of eggs holding gradually decreased.The T.ostriniae cannot parasitize the eggs of the manually-extracted unfertilized eggs of Chinese oak silkworm,and the total amount of eggs is the amount of egg holding,showing a gradual upward trend.There is no significant difference between the time periods after 8 hours of parasitism.The prolonged time of parasitism of T.leucaniae can gradually adapt to themanually-extracted unfertilized eggs of Chinese oak silkworm A.pernyi.It shows a small amount of parasitism from 16 h,and the parasitic amount gradually increased at 20 and 24 h.The amount of egg holding in its body decreased slightly from 16 h,while the total amount of eggs,there was a slight increase at 16 h.However,for the parasitic naturally laid eggs by A.pernyi,T.dendrolimi and T.chilonis can only parasitize a small amount,while the other two species cannot.The egg holding capacity and total egg volume of the four parasitic wasps showed that there was no significant change in the parasitic volume of T.dendrolimi in each time period,and the egg holding volume and total egg volume in the body showed a gradually decreasing trend.There was a slight decrease in the amount of eggs conceived by T.chilonis and the total amount of eggs at 20 and 24 hours,but there was no significant difference in each time period.The total amount of eggs of T.ostriniae was the amount of eggs concealed in the body,showing a gradual upward trend,and there was no significant difference between the various time periods after 8 hours of parasitism.The amount of eggs concealed and the total amount of eggs in the T.leucaniae did not change significantly with the prolongation of the parasitic time.The results shows that the suitability of different hosts to different Trichogramma was significantly different,and the host with different suitability significantly affects the parasitism of Trichogramma,which in turn affects the development of eggs in the wasp species.更多还原