林间释放平腹小蜂防治银杏大蚕蛾研究

笔者于1999－2000年在城口银杏大蚕蛾发生区释放用其卵繁育的平腹小蜂防治银杏大蚕蛾，结果表明：放蜂区虫卵寄生率明显提高，其校正寄生率为69.30%，是一种可利用的天敌昆虫。可在银杏大蚕蛾发生区内推广应用。     

平腹小蜂繁殖新方法——屏膜繁殖法

平腹小蜂是一种荔枝蝽象卵期的寄生蜂。到目前为止,室内人工繁殖平腹小蜂基本仍用木箱作蜂箱繁殖。这种陈旧的方法花工多,繁蜂速度慢,蜂箱损耗大,且繁殖出的蜂寄生率、羽化率均不高。为了高效快速繁殖平腹小蜂供生产上使用,广东省生物防治实验站陈称康等人于今年4月至7月先后用屏膜挂卵卡繁殖平腹小蜂四个世代、40批次,育出蜂11.4万头获得成功。蜂的平均寄生率、羽化率分别为95.46％和90.23％,雌     

舞毒蛾卵平腹小蜂野外寄生柞蚕卵规律的观察

2005年5～9月,在长春市吉林农业大学校园内的杨树林和李树林内进行人工挂放柞蚕An- theraea pernyi Guerin-Meneville卵卡诱集本地平腹小蜂Anastatus spp．寄生试验。结果表明杨树林中的舞毒蛾卵平腹小蜂Anastatus japonicus Ashmead的寄生率最高可达23．1%,李树林中的舞毒蛾卵平腹小蜂的寄生率最高可达33．5%,李树林中舞毒蛾卵平腹小蜂的寄生率明显高于杨树林。全年中,舞毒蛾卵平腹小蜂分别在6月下旬和8月上旬出现2次寄生高峰。     

卵寄生蜂对荔枝蝽的控制作用

通过对荔枝蝽卵块的标记调查,在综防园中采集到荔枝蝽的两种卵寄生蜂——平腹小蜂和跳小蜂。在荔枝蝽产卵的中、后期,两种寄生蜂对荔枝蝽卵总寄生率达４１．９％～４７．１％,其中平腹小蜂寄生１６．７％～１８．４％,跳小蜂寄生２３．５％～３０．４％。在化防园中仅采集到平腹小蜂,且其寄生率相当低,只有０．９％～２．８％。     

荔蝽卵平腹小蜂对荔枝蝽的控制效果

于2000年至2001年在广西北流进行了释放荔蝽卵平腹小蜂防治荔枝蝽的田间试验，第1年放蜂2次，荔蝽卵平腹小蜂寄生率为82．5％，第2年在放蜂量减少一半的情况下，荔蝽卵平腹小蜂寄生率为48．3％，自然天敌荔蝽卵跳小蜂寄生率2a分别为11．8％和22．5％，处理区的残存荔枝蝽若虫2a均为2头／株，而对照区的残存荔枝蝽若虫第1年为29头／株，第2年达90头／株。试验显示：处理区荔枝蝽若虫数量显著降低，荔蝽卵平腹小蜂能有效地控制荔枝蝽的危害。     

平腹小蜂和荔枝蝽象卵壳构造扫描电镜研究

在我国,利用平腹小蜂防治荔枝蝽象已得到广泛的应用。人工繁殖平腹小蜂常以柞蚕卵和蓖麻蚕卵为寄主。在野外,平腹小蜂主要寄生于荔枝蝽象卵内,发育成蜂后破卵壳而出。寄生蜂产卵时先要刺破寄主卵壳,因此寄生蜂的寄生与寄主卵卵壳的结构关系密切。本文是平腹小蜂及其寄主荔枝蝽象卵壳结构研究的结果,主要是利用扫描电镜观察两种卵的表面花纹,受精孔和气孔结     

柳杉毛虫的主要寄生性天敌种类调查

柳杉毛虫Dendrolimus houi(Lajonquiere)是严重为害我国柳杉Cryptomeria fortunei(Hooibrenk)的最主要食叶害虫之一,调查柳杉毛虫的寄生性天敌资源并开展寄生效能初步评价,对于进一步筛选获得优势天敌种类并开展林间应用具有重要意义。本次调查采集并鉴定了柳杉毛虫的10种寄生性天敌:分别为松毛虫凸腿小蜂Kriechbaumerella dendrolimi(Sheng et Zhong)、广大腿小蜂Brachymeria lasus(Walker)、云南黑青金小蜂Dibrachys yunnanensis(Yang)、平背囊爪姬蜂Theronia depressa(Gupta)、短柄短角平腹小蜂Mesocomys breviscapis(Yao et Yang)、枯叶蛾短角平腹小蜂Mesocomys trabalae(Yao et Yang)、黑角狭颊寄蝇Carcelia nigrantennata(Chao et Liang)、蚕饰腹寄蝇Blepharipa zebina(Walker)、星毛虫狭颊寄蝇Carcelia illiberisi(Chao et Liang)、瘦钩鬃麻蝇Sarcorohdendorfia gracilior(Chen);其中,云南黑青金小蜂、短柄短角平腹小蜂、枯叶蛾短角平腹小蜂、平背囊爪姬蜂、星毛虫狭颊寄蝇、黑角狭颊寄蝇6种为福建省新纪录种;同时柳杉毛虫也是首次报道为它们的自然寄主。同时松毛虫凸腿小蜂与短柄短角平腹小蜂具有较高的自然平均寄生率(7.24%和10.67%)和平均子代数量(33头/蛹与20头/雌),平背囊爪姬蜂平均子代蜂数较多(4头/寄主),且能与多种寄生性天敌联合控害,是其优势天敌种类。最后,简述其识别特征,以利进一步保护、开发和利用。     

荔蝽卵平腹小蜂和松毛虫赤眼蜂种间对寄主竞争的研究

室内以人工卵和柞蚕卵为寄主,观察荔蝽卵平腹小蜂 Anastatus japonicus(简称平腹小蜂)和松毛虫赤眼蜂 Trichogramma dendrolimi(简称赤眼蜂)种间对寄主的竞争情况。实验表明:平腹小蜂寄生后两天内接赤眼蜂,在接蜂时间间隔为0天,一天和两天时,含赤眼蜂的寄生卵分别占53.66%、46.11%和47.20%;含平腹小蜂的寄生卵分别占27.09%、28.53%和23.08%;含两种蜂的寄生卵分别占19.25%、25.36%和29.72%。若两种蜂接蜂时间间隔为四天和八天时,含赤眼蜂的寄生卵分别降为15.79%和11.88%;而含平腹小蜂的寄生卵分别增加至48.35%和52.15%;含两种蜂的寄生卵比例也有所增加,分别占35.86%和35.15%。弱者不能完成发育而在出蜂前死亡,强者也难繁殖出正常的后代。实验室繁殖时应避免两种蜂混杂而降低出蜂质量。过寄生也会使平腹小蜂幼虫产生种内竞争现象,同龄幼虫以二龄期竞争最为激烈;不同龄期则因一龄幼虫行动活跃,利用长而硬的刺毛刺伤二龄甚至三龄幼虫而成为营养争夺的胜利者。过寄生虽然可以正常出蜂但已经造成寄生卵的浪费。生产实践中应控制正常的蜂卵比,减少这种现象产生。     

日本平腹小蜂对点蜂缘蝽的控害潜能研究

为了评价日本平腹小蜂对点蜂缘蝽的控害能力,采用系统观测法测定了日本平腹小蜂(Anastatus japonicus)的生长发育、繁殖及寿命。在设置寄主点蜂缘蝽卵密度为1、5、10、15粒和20粒的条件下,研究了日本平腹小蜂的寄生功能反应。结果表明,日本平腹小蜂从卵到成蜂的平均发育历期为20.78 d,雌蜂平均寿命为31.36 d,平均产卵15.65粒。在试验测定的5个寄主密度梯度下,日本平腹小蜂的寄生功能反应符合Holling Ⅲ模型,其方程为Na=11.30exp(-7.99/N)。其理论最高寄生量为11.30粒,最佳寻找密度为7.99粒。     

利用人工寄主卵繁殖平腹小蜂防治荔枝蝽

用人工寄主卵繁殖平腹小蜂防治荔枝蝽,首次获得成功。筛选出12种人工卵卵液配方、卵壳材料和“羊1号”防腐剂。人工寄主卵繁殖平腹小蜂,化蛹率74.34～93.49％,羽化率66.5～89.49％。在笼罩荔枝上及果园中释放防治荔枝蝽,卵粒寄生率分别达89.12％和89.45％。初步看出,用人工寄主卵代替自然寄主卵来繁殖平腹小蜂,可能是解决中间寄主的新途径。     

两种平腹小蜂的研究进展

平腹小蜂是一类优良的卵寄生蜂, 是寄生性天敌昆虫中已具有成熟的规模化繁殖技术和田间释放技术, 并成功应用于害虫防治的天敌昆虫之一, 在防治果树蝽类害虫方面效果显著?平腹小蜂的发育学?行为学?生态学?繁殖技术及田间应用技术的研究已有60多年历史, 近年来, 分子生物学和高通量测序手段的应用促进了对平腹小蜂的生理生化基础研究, 研究领域也开始拓宽?本文从分类学?生物学特性?人工繁殖?共生菌?滞育?寄生机制?毒液蛋白和味觉受体基因等方面, 对目前广泛应用于荔枝蝽和茶翅蝽防治的2种平腹小蜂, 麻纹蝽平腹小蜂Anastatus fulloi Sheng &Wang和日本平腹小蜂 Anastatus japonicus Ashmead近30年的研究进展进行归纳和总结, 并对今后的研究方向进行展望, 旨在为平腹小蜂的深入研究和应用技术研发提供参考?     

油松人工林地上生物量、叶面积指数与林分密度关系的研究

在内蒙古大青山区应用"平均标准木法"测定30a生油松人工林的地上生物量,并对相似立地条件下,不同林分密度的油松人工林地上生物量及其分配规律进行了研究。结果表明:1)林分密度对油松人工林平均单株生物量和单位面积林木总生物量均有显著的影响。前者随林分密度的增加而下降,且下降的幅度越来越小,可由方程y=axb来描述;后者随林分密度的增加而上升,当密度达到一定值(阳坡为3000株/hm、阴坡为4000株/hm时)生物量增长缓慢甚至不变,可由方程y=a+bln(x)来描述。2)乔木层生物量是林分总生物量的重要组成部分。阳坡乔木层所占比例为76.06%~88.20%,阴坡乔木层所占比例为83.19%~93.75%。3)叶面积指数随林分密度的增加而增加,在相同密度条件下阳坡的叶面积指数大于阴坡,且密度愈大两者相差愈大。     

蒲螨生物学习性及对椰心叶甲龄期选择性的初步研究

在室内温度(25±2)℃,光周期L∥D=12h∥12h,相对湿度(75±10)%条件下,对蒲螨的寄生行为、其对寄主龄期的选择性、膨腹体的发育过程以及世代生活史进行观察。结果表明:在室内蒲螨能很好地找寻寄主并寄生。平均每头雌螨一生产雌43.31头,产雄4.82头,产子期14.06d,寿命为21.21d。蒲螨对椰心叶甲各龄期的选择性达极显著差异,最喜欢寄生蛹,选择寄生率达到96.67%;其次是5龄幼虫,寄生率为60.00%;1龄幼虫的寄生率最低,只有10.00%。     

两索线虫对晚稻田不同类型褐飞虱的寄生力研究

在3个不同水稻品种上,研究江西南昌晚稻田内两索线虫对不同翅型和性别褐飞虱的寄生能力。结果表明:在同一水稻品种上,两索线虫对不同类型褐飞虱的寄生率之间存在显著差异,其寄生率的大小顺序为:短翅型雌虫长翅型雌虫短翅型雄虫长翅型雄虫。其中,在短翅型雌虫体内,最高寄生率达45.16%;而在长翅型雄虫体内,最低寄生率仅为2.15%。在水稻品种株两优120上,两索线虫对短翅型雌虫的寄生数量达3头的占9.68%,对短翅型雌虫和长翅型雌虫寄生有2头的分别占6.45%和8.33%;在丰华占和合美(丰)上,对短翅型雌虫寄生数量最多为2头,寄生率分别为5.25%和4.35%;对不同类型褐飞虱的寄生数量为1头的均较高。可见,两索线虫对田间褐飞虱种群具有较强的寄生能力,可有效抑制褐飞虱的发生与危害。     

森林固碳效益的经济核算——以甘肃小陇山林区为例

小陇山林区位于甘肃东南部,全林区以锐齿栎、油松、栓皮栎、杨、桦树、落叶松、华山松、云、冷杉以及其他阔叶混交等8类林分为建群树种。森林的单木生物量(W)与胸高直径(D)、以及与胸径-树高双变量(D2H)之间均存在着紧密的相关关系。用标准地每木调查数据分别建立了8种林分的生物量回归分析模型,并以此计算了8种林分的碳储存密度,依各林分面积、生物量与二氧化碳实物量之间的转换系数、二氧化碳与纯碳量之间的折算系数分别计算了全林区乔木层的总生物量为2.85×107t、固定的二氧化碳实物量为4.65×107t,折算的纯碳量1.27×107t。用造林成本法估算了全林区乔木层固碳的经济效益为2.78×109元人民币。     

橡胶盔蚧寄生蜂的种群结构与空间分布研究

通过普查与定点调查的方法,研究了橡胶盔蚧寄生蜂的种群结构和橡胶盔蚧及其寄生蜂的空间分布。结果表明,橡胶盔蚧天敌寄生蜂达10种,其中优势种2种,常见种4种,稀有种4种。优势种优雅岐脉跳小蜂和蜡蚧褐腰啮小蜂分别占整个种群数量的64.32%和11.76%。橡胶盔蚧寄生蜂在橡胶树不同方位上的分布不同。在层次上,寄生蜂在上层的平均寄生率要比下层高;在方位上,寄生蜂在南面的平均寄生率最高,而在北面的平均寄生率最低。通过Taylor幂法和Iwao的回归分析对橡胶盔蚧及其寄生蜂的空间分布型进行研究,得出结果一致,即橡胶盔蚧及其寄生蜂种群在橡胶树上的空间分布型均为聚集分布,且种群密度越高分布越聚集。     

Forest recovery after clear-cutting in Chinese pine(Pinus tabuliformis) plantations of North China

In Hebei Province of North China, forest was recovered with natural recruitment in plantations with large area of clear-cutting Chinese pine(Pinus tabuliformis). This study was aimed to demonstrate the dynamic characteristics of recruits during the natural recruitment. Both plot survey and the spatial point-pattern analysis were performed. Five developmental stages of natural recruitment were selected and studied, including 1 year before and 2, 5, 8, and 11 years after clear-cutting. Different slope aspects were also included. Natural recruitment was always dominated by Chinese pine with a proportion of higher than 90%. For plots of 1 year before clear-cutting on east-and north-facing slopes, recruit densities were 7886 and 5036 stems/hm2, the average heights were 0.78(±0.85) and 1.06(±1.15) m, and the average diameters at breast height(DBH) were 3.21(±1.38) and 2.91(±1.38) cm, respectively. After clear-cutting, recruit density was initially increased, then it was gradually declined with time; however, the variation of average DBH was contrary to that of recruit density. Both of them were no longer varied between 8 and 11 years after clear-cutting. The average height of recruits continued to increase after clear-cutting. For the plots of 11 years after clear-cutting on east-and north-facing slopes, average heights of recruits reached 2.00(±1.14) and 2.24(±1.20) m, respectively. The statuses of recruits on north-facing slopes were better than those on east-facing slopes after clear-cutting. Meanwhile, recruits on east-facing slopes were always aggregated at small scales, while spatial pattern of recruits varied with time on north-facing slopes. Moreover, forest was recovered more quickly by natural recruitment than by artificial afforestation after clear-cutting. The structural diversity was higher in naturally regenerated forests than in plantations of the same age. Our results demonstrated that clear-cutting of Chinese pine plantations recovered by natural recruitment has the potential to be an effective approach for establishing multifunctional forest.     

四川省稻田越冬代二化螟寄生性天敌的研究

二化螟Chilo suppressalis是水稻生产上重要的常发性害虫, 以大龄滞育幼虫在稻桩中越冬, 研究其寄生性天敌, 对于害虫发生动态预警和防治具有重要意义。通过剥查四川地区稻桩内越冬代二化螟幼虫并室内饲养羽化收集天敌, 鉴定天敌种类和调查自然寄生率发现:2017年-2018年, 2018年-2019年及2019年-2020年, 寄生蜂自然寄生率分别为1.1%~8.6%, 1.5%~11.7% 和 1.9%~9.0%, 年度间自然寄生率无明显差异; 寄生蜂自然种群主要有螟甲腹茧蜂 Chelonus munakatae (Munakata)、大螟钝唇姬蜂 Eriborus terebrans (Gravenhorst)、中华茧蜂 Amyosoma chinensis (Szepligeti)、绒茧克氏金小蜂Trichomalopsis apanteloctena (Crawford)、螟蛉瘤姬蜂 Itoplectis naranyae (Ashmead)、螟黄足盘绒茧蜂 Cotesia flavipes (Cameron)、环腹瘿蜂 Figites sp.、稻螟小腹茧蜂 Microgaster russata (Haliday)、黏虫白星姬蜂 Vulgichneumon leucaniae (Uchida)和二化螟黑卵蜂Telenomus chilocolus(Wu et Chen)。四川省越冬代二化螟寄生性天敌的优势种为螟黄足盘绒茧蜂和螟蛉瘤姬蜂, 部分地区每年自然寄生率维持在较高的水平。     

Effect of vegetation on soil water retention and storage in a semi-arid alpine forest catchment

The runoff generated from mountainous regions is recognized as the main water source for inland river basins in arid environments. Thus, the mechanisms by which catchments retain water in soils are to be understood. The water storage capacity of soil depends on its depth and capacity to retain water under gravitational drainage and evapotranspiration. The latter can be studied through soil water retention curve (SWRC), which is closely related to soil properties such as texture, bulk density, porosity, soil organic carbon content, and so on. The present study represented SWRCs using HYDRUS-1D. In the present study, we measured physical and hydraulic properties of soil samples collected from Sabina przewalskii forest (south-facing slope with highest solar radiation), shrubs (west-facing slope with medium radiation), and Picea crassifolia forest (north-facing slope with lowest radiation), and analyzed the differences in soil water storage capacity of these soil samples. Soil water content of those three vegetation covers were also measured to validate the soil water storage capacity and to analyze the relationship between soil organic matter content and soil water content. Statistical analysis showed that different vegetation covers could lead to different soil bulk densities and differences in soil water retention on the three slope aspects. Sand content, porosity, and organic carbon content of the P. crassifolia forest were relatively greater compared with those of the S. przewalskii forest and shrubs. However, silt content and soil bulk density were relatively smaller than those in the S. przewalskii forest and shrubs. In addition, there was a significant linear positive relationship between averaged soil water content and soil organic matter content (P<0.0001). However, this relationship is not significant in the P. crassifolia forest. As depicted in the SWRCs, the water storage capacity of the soil was 39.14% and 37.38% higher in the P. crassifolia forest than in the S. przewalskii forest and shrubs, respectively, at a similar soil depth.