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In Honghuaerji region,Scambus sp. is an effective natural enemy of the mongolian scotch pine cone weevil (Pissodes validiirostriis Gyll). The percentage of parasitism on larvae of the mongolian scotch pine cone weevil amounts to 20 to 30% commonly, sometimes
as high as 45% or more, thus significantly regulating the weevil population. But the high mortality of larvae ofScambus in winter, which according to the surveys (conducted in 1986, 1987, and 1988) were 24.00%, 51.03% and 47.70% respectively,
seriously influenced the natural suppression effect. In order to reveal the cause of winter death of this natural enemy, from
1990 authors studied the winter physiological indices, cold hardiness and overwintering protection ofScambus larvae, in the purpose of providing scientific basis of usingScambus in biological control. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(4):334-340
White spruce (Picea glauca (Moench) Voss) is host to several pests, including the white pine weevil (Pissodes strobi (Peck)) and the green spruce aphid (Elatobium abietinum (Walker)). The larvae of the white pine weevil damage spruce leaders by consuming the cortex while the green spruce aphid is a defoliator. White spruce emblings (seedlings produced by culturing tissues from seed embryos) from 18 families previously ranked for resistance to the white pine weevil were defoliated to varying degrees by the green spruce aphid in a natural outbreak that developed within a holding shadehouse. A strong relationship was shown between damage caused by the aphids and weevil resistance. Emblings ranked as highly weevil - resistant sustained significantly less aphid defoliation. 相似文献
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为研究CCA防腐剂的固定性能,用银杏,欧洲赤松,山毛榉和牡竹进行比较试验。根据德国标准(DIN 52172Ⅱ-1977),试验设置1周、2周和4周的不同处理。对于Cu来说,处理后1周就已经固定得很好,流失量在各树种间无甚区别。而Cr的固定较慢,且各树种间差别较大。处理4周后,Cr仅在欧洲赤松中完全固定,在银杏和山毛榉中Cr的固定较好,而牡竹的Cr流失量仍为4%。 相似文献
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1992-1994年,在浙江马尾松林里进行昆虫及蜘蛛群落,松毛虫天敌和种群动态的分析。结果表明:(1)15年生马尾松针叶立体分布,确认砍枝取薪以留7轮为好,不低于留4轮;(2)马尾松林昆虫群落分属18目118科,其中直翅目,鞘翅目,同翅目,膜翅目,半翅目占优势,经测定,龙游县落结构复杂,分布均匀,群落与层次,坡向,郁闭度,灌层盖度关系密切;(3)蜘蛛群落分属19科46种,其中萧蛸科,猫蛛科和蟹蛛科 相似文献
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Investigations were made in korean pine, mongolian scots pine and dahurian larch plantations in Laoshan Plantation Experiment
Station of Maoershan Experiment Forest Farm of Northeast Forestry University. Data are tabulated on the amount and seasonal
and annual fluctuations of fractional composition of the litter (conifer needles, branches, cones, bark scales, broad leaves)
in the three plantations. The accounts of conifer needle branch and bark scale litter are as follows: korean pine: 71.16%,
6.23% and 7.32%; mongolian scots pine: 43.65%, 18.52 % and 32.12%; dahurian larch: 90.30%, 7.83% and 1.85%. There are certain
broadleaf litter in dahurian larch and mongolian scots pine plantations (account for 7.61% and 8.92% respectively). The litter
wither and fall concent ratively in autumn in dahurian larch plantation and scattered all year long in korean pine and mongolian
scots pine plantations. Along with the increase of stand age, the absolute amount of litter tend to increase, the relative
amount of main fractional compositions (conifer needle, branch and bark scale) in korean pine and mongolian Scots pine plantations
maintain stead, whereas in dahurian larch plantation, the relative amount of conifer needle is decreased gradually and the
relative amount of other fractional compositions are increased gradually. 相似文献
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Koreanpine(Pinuskoraiensis)(KP),mongolianscotspine(Pinussylvestrisvarmongolica)(MSP)anddahurianlarch(LarisgmeIinii)(DL)arethemainconiferousspeciesforforestationinnortheastregionofChina-LargeareplantationsofKP,MSPandDLhavebeenplantedintheregionsincel95o's.Whetherthestandstabilityandecolo-gicalequilibriumcanbemaintainedandtheforestfloorproductivitycanincreaseintheplantati0nsismainlydeterminedbytheamount,fracti0nalandchemicalcomp0sitionanddecomp0sitionrateof1itters,exceptforinfluenceofl0ca… 相似文献
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芽梢斑螟幼虫危害特点及其密度估计的研究 总被引:4,自引:0,他引:4
芽梢斑螟是马尾松二年生球果的重要害虫。根据种子园雄花发生特点,研究了芽梢斑螟越冬幼虫转移危害及其在树冠和林中的分布规律。结果表明,7轮生枝的马尾松树冠上,芽梢斑螟越冬幼虫集中侵害第六、七轮生枝上的二年生球果,球果被害率达53.6%,幼虫数量占总数的58.8%。种子园内不同无性系有少雄(花)、中雄和多雄树之别,芽梢斑螟越冬幼虫转移后的危害率及其数量分布,随马尾松雄梢率的增加呈递增的趋势。危害率(y1)和幼虫数量(y2)与雄梢率(X)的回归方程式分别为y1=0.660+0.473X,y2=-0.829+0.303X 相似文献
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粉拟青霉防治油(赤)松毛虫流行病研究 总被引:3,自引:0,他引:3
越冬油(赤)松毛虫自然死亡的主要原因是真菌疾病,应用粉拟青霉防治越冬的油(赤)松毛虫比白僵菌更有效,多年的林地防治取得了70%以上的稳定杀虫效果,侵染以晚秋和早春为主,严冬季节很少。幼虫春季上树后仍有一部分死亡,这是疾病潜伏期造成的死亡滞后于侵染的现象,计算总死亡率应加上这一部分。影响该菌防治越冬幼虫效果的主要因子不是湿度,而是温度,表现在阳坡效果好于阴坡。 相似文献
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针叶树球果的物理力学特性及其对种子采收的影响 总被引:1,自引:0,他引:1
针叶树球果的物理力学特性是影响针叶树种子采收的重要因素,也是确定采种方式,研究和设计采种机械的重要依据。本文对油松、樟子松球果的基本物理特征、果柄的拉断阻力及果柄的切断阻力进行了试验研究,分析了球果的物理力学特性对采种的影响,并提出了一些建议。 相似文献
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灭幼脲对杨干象作用机制和防治的研究 总被引:11,自引:0,他引:11
采用灭幼脲油剂,油胶悬剂等,用点涂的方法对杨干象幼虫和成虫进行了适时防治,结果表明:灭幼脲油剂可抑制表皮几丁质的合成达15%以上;灭幼脲油胶悬剂抑制杨干象成虫精巢和卵巢的发育,可使成虫产卵间降低40-70%,使卵的孵化率降为零。这为杨干象的防治找到一条高效,安全,经济,易全文的新途径。 相似文献
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INTRODUrnoNScotSpine(Pihussyhasthevar.mongo-lica)jsafme'speiesagainstcol4twand'Poortoilcondihon,whichisoneofthemainplantingsPeciesinnorth-eastregionofChinaandthebe-North"proteChonforest.ThenatUralSctsPinestandsgrowingonthesand-landinHonghuaehiaremanagedastheparent-standforthebaseofseedresource.Butthequalityofpine-conewasseriouslydamagedbythepine-coneweevil..ManyyearssurveyshowedthattheloserateofconewasbetWeen3o%and5o%,evenupto68%inseriouslydamagedyears.Thereductionof1oneyieldinfluenced… 相似文献
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INTRODUCTIONInwesternpartofHei1ongiiangprov-ince,scotchpine(Pinussylvestris)iswindbreak,sand-fixationandcommercialforest.It'soneofthemaintreesinthecon-structionof"threeNorth"shelterforest.ThewoodcharacterisexceI1ent.Sothedis-cussionandvaluationonScotchPineproductivityhasimportantmeaningoncommerce,windbreakandsand-fixation.Theanalysisofvolumegrowth,bio-productivityandre1ationshipsbe-tweenvo1umegrowthanddensityandbe-tweenbio-productivityanddensity,gaveevidencetostudyfastgrowingscotchpine… 相似文献
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兴凯湖松是介于赤松与樟子松之间在兴凯湖地区长期演化的自然杂交树种,属于国家二级保护植物,同时从分布来看又非常稀少,所以笔者建议应该对兴凯赤松加大力度进行保护。 相似文献
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松毛虫应用价值研究在综合管理中的作用初探 总被引:9,自引:0,他引:9
探讨了松毛虫应用价值研究与松毛虫综合管理的关系。介绍了云南民间利用松毛虫的概况,简述了松毛虫利用价值研究所取得的进展和成果。从昆虫资源的角度来看,松毛虫的种资源是相当丰富的。从森林有害生物综合管理的观点出发,松毛虫也是森林生态系统中的重要成员。如果人对松毛虫资源进行开发利用,也可以把人视为森林生态系统中抑制松毛虫种群数量增长的天敌。人类的天敌作用与对松毛虫的需求量有密切的关系。松毛虫的应用价值越大,需要量越多,松毛虫种群数量的抑制作用也就越大。因此,人类开发利用松毛虫可以视为综合管理的技术之一。 相似文献