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1.
Fifty pole stage trees were inoculated with O. polonicum at monthly intervals between May and September. Most infection, measured as the area of sapwood blue‐stained, occurred in July and least in May and September. The difference between July, August and September might be explained by the effect of temperature on fungal growth, but in May and June the trees had a higher resistance than expected. Tree resistance was correlated with resinosis. Tree variables not correlated with resistance were DBH, annual ring width, periodic growth, vigor index, or phloem carbohydrate concentration.  相似文献   

2.
In 1991 and 1992 studies on Dalbergia sissoo Roxb. showed the availability of ample amount of viable seed from November to May. Viability of seeds collected from December to March was more than 90 per cent. There was a slight but significant decrease in germination from March to may. Again germination per cent was slightly and significantly decreased from May to July. Thereafter, seed availability and viability were got drastically reduced. Sufficient viable seed of Dalbergia sissoo Roxb. can be collected at any time from November to July.  相似文献   

3.
The life circle and bionomics ofLymantria dispar was studied from the May to the July of 1997 in Tulihe Forestry Enterprise of Inner Mongolia. The results showed thatL. dispar has one generation in a year, larvae overwinters in eggs, and last 50 days to grow up. From the completing of larvae period to the appearing of adults lasts 11 days. The study made a basis for the period forecasting of L.dispar in Inner Mongolia.  相似文献   

4.
Experiments were conducted to test whether Fourier transform‐infrared (FT‐IR) spectroscopy, coupled with chemometric methods, can distinguish healthy xylem tissues collected from elms known to differ significantly in their susceptibility to Ophiostoma novo‐ulmi Brasier. Twig samples from resistant Ulmus pumila L., susceptible U. minor Mill. and resistant U. minor clones were harvested on 1 May, 15 May, 1 June, 1 July and 1 September 2004, and subjected to FT‐IR analysis. The application of principal component analysis to the spectral data, followed by discriminant function analysis, discriminated between the three groups of samples in all harvesting dates. The examination of the DF‐loading plots allowed the identification of key regions within the spectra for the separation between clusters. The chemical assignments of these key regions allowed the following interpretations to be made: (i) U. pumila tissues contained enhanced levels of starch, cellulose and lignin with respect to U. minor tissues and (ii) resistant U. minor tissues contained enhanced levels of starch, cellulose and pectic polysaccharides with respect to susceptible U. minor tissues. The possible roles of the compositional differences in disease resistance, as well as the potential use of FT‐IR spectroscopy and chemometrics as a tool for screening resistant elms are discussed.  相似文献   

5.
Zusammenfassung In den Jahren 1977 bis 1979 im Raum Seefeld-Leutasch, Nordtirol, in Gebirgs-Tannenmischwäldern durchgeführte Untersuchungen über bösartige Tannenläuse (Adelgidae) ergaben, daß als einzige Art dortDreyfusia nordmannianae auftrat. Dabei konnten sich Stammläuse auch an Trieben weiterentwickeln. Die Eiablage fand zwischen Anfang Mai und Anfang Juni, das Schlüpfen der Neosistentes zwischen Mitte Mai und Ende Juli statt. Die Zahl der Neosistentes übertraf jene der Neoprogredientes beträchtlich. Der Besatz der Tannen mitDreyfusia war an sonnigen Standorten, verbunden mit Waldweide, besonders hoch. Im Raum Seefeld-Leutasch was der Anteil der vonDreyfusia befallenen Tannen deutlich geringer als im Raum Kufstein, doch starben im Raum Seefeld dreimal so viele Bäume ab wie im Raum Kufstein.
Studies on taxonomy, development and damages of the balsam woolly aphid, Dreyfusia nordmannianae (Eckst.) in the area of Seefeld-Leutasch (the Northern Tyrol)
Investigations which were made in 1977–1979 in the alp mountains around Seefeld on the Adelgidae sucking on silver fir showed that there wasDreyfusia nordmannianae only. Time of egg laying was from early May till early June, and of emergence of the neosistentes from middle May till late July. The number of neosistentes was much greater than those of neoprogredientes. Most aphids were to be found in those stations where there was most light and wood grazing. In the area of SeefeldD. nordmannianae attacked the firs in a less extent than in the area of Kufstein, but in the former the fir trees died three times more than in the latter.


Mit einer Abbildung und 4 Tabellen

Teil einer Dissertation am Institut für Zoologie der Universität Innsbruck, 1980.  相似文献   

6.
Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), (= A. marcopoli Obenberger), is an important bark beetle attacking ash trees (Fraxinus spp.). It is very difficult to detect and control because of its highly concealed life history. This pest mainly distributed in partial Asian countries (China, Japan, Korea, Mongolia) and Far East Russia, while in China it presented in Heilongjiang, Jilin, Liaoning, Shandong, Inner Mongolia, Hebei, Taiwan Provinces and Tianjin City, etc. The important timber species F. mandshurica and gardening tree F. velutina were damaged severely in northern China. Spathius agrili Yang (Hymenoptera: Braconidae) is an important ectoparasitic wasp of the EAB larvae. This parasitoid has the potential to use as an excellent biological control agent for suppressing populations of EAB. The differences of emergence date between overwintered S. agrili and its host, parasitism rates at different periods, relations between parasitism rates and host densities, and relationships between ovipositions of braconid wasp and body sizes of host larvae were studied using methods of regular surveys in forests and observations in laboratory. Results revealed that the emergence of S. agrili was more than one month later than that of its host. It suggests good synchrony between parasitoid emergence and host availability. The overwintered S. agrili emerged from mid June to mid August with the peak in July in 2003, and it lasted from late May till late July with the peak during late June to early July in 2004. While the EAB emergence period ranged from mid May to late May in 2003, it ranged from mid April to mid May in 2004 (in laboratory). The emergence date of parasitoid asynchronously inosculated with the optimum developmental instars of the earliest host larvae, which was the result of a long-term co-evolution between the two species. It was also suggested that the parasitoid S. agrili could be a specialized natural enemy for EAB. The natural parasitism rates on the whole gradually increased in field with time. The body sizes of host larvae, i.e. larval instar, affected the decision of parasitoid S. agrili to lay eggs or not. Under natural conditions, this parasitoid usually oviposited only on those host larvae with a prontum and body width more than 1.5 mm, and a body length in excess of 12 mm, i.e. the third or fourth instar larvae. These findings would consequentially contribute to the further successfully biological control of the trunk borer. __________ Translated from Acta Ecologica Sinica, 2006, 26(4): 1,103–1,109 [译自: 生态学报]  相似文献   

7.
2019年至2021年对云南省昆明市呈贡回回营社区混合集群的鹭鸟开展调研,分别于2019年10月, 2021年4、5、6月对鹭群进行4次访问。2019年10月,鹭鸟繁殖栖息地主要由竹子和少量桉树构成,地面覆盖大量落叶;其间污水流淌,形成数条小河和一个池塘。2021年统计每棵竹子和桉树上鹭巢数量及营巢鹭鸟种类,并测量巢距离地面的垂直高度。该地发现有小白鹭、黑顶夜鹭和牛背鹭筑巢繁殖,其中小白鹭和黑顶夜鹭构成群落数量主体。2021年4月记录21个鹭巢(小白鹭与黑顶夜鹭),5月记录41个鹭巢(小白鹭、黑顶夜鹭和牛背鹭;此月为繁殖高峰),6月记录8个鹭巢。鹭巢距离地面平均距离为8.78 m。目前,该鹭群由于回回营面临拆迁而受到威胁,为此提议保留鹭群所在的繁殖地,并改善研究地点及周边地区水质情况。  相似文献   

8.
为了评价人工剪梢防治微红梢斑螟对松树生长的影响,分别在当年5月份和7月份对微红梢斑螟危害过的马尾松、湿地松幼林实施人工剪梢防治微红梢斑螟幼虫.结果表明:人工剪梢防治微红梢斑螟对松树生长的影响与剪梢时间和树种有关.人工剪梢防治对马尾松、湿地松地径生长均有一定的促进作用,其中5月份剪梢的马尾松地径增长最明显,达14.87%...  相似文献   

9.
In order to test, under warehouse conditions, the longterm effectiveness of THURICIDE® dust, containingBacillus thrungiensis var.kurstaki (=Serotype H3a, 3b), with a viable spore count of 6 to 10 million per mg, the biopreparation was applied to rye, stored in bulk, on which larvae of the Indian Meal Moth (Plodia interpunctella Hbn.) were fed. From May to October, moth eggs were exposed monthly to rye dusted with 100 mg (320×103 IU) resp. 150 mg (480×103 IU) THURICIDE® dust per 100 g grain respectively. At a concentration of 100 mg 0.2% to 2.4% of the larvae, which hatched from the eggs in May, June and August, survived to the adult stage. No moths were observed in the experiments continued during September and October. At a cocentration of 150 mg, only in the experiments started in June and July 2.7% and 0.1% respectively of the eggs and larve survive to become adults. In the experiments of May, August, September and October, none were stated to have survived. The biopreparation-free control of May, June and July showed that about 75% of the eggs/larvae reached the adult stage, whereas, in August, September and October, untreated eggs and larvac reaching the adult stage amounted to 14% and 1% respectively. In reason of the combination of the efficiency ofBacillus thuringiensis and of the only small amount of surviving larvae due to the low temperatures during autumn and winter months, the surface application of THURICIDE® dust would be promising measure for combatting moth pests in bulk-stored grain.  相似文献   

10.
The influence of seasonal variation, indole-3-butyric acid (IBA) and type of cuttings was examined on induction and growth of adventitious roots in Bambusa nutans Wall. and Bambusa tulda Roxb. Singlenode culm and culm-branch cuttings from the mature culms were provided with immersion treatment for 24 h of either water (control) or 2 mM IBA in four different seasons, i.e., spring (mid February), summer (mid May), rainy (mid July), and winter (mid November) and maintained for two months in the mist chamber at the relative humidity of (70±5)% and the temperature of (30±2)°C. In B. nutans, adventitious rooting occurred in both types of cuttings in all the seasons with the best rooting in the summer season i.e., May (88% in culm cuttings) and the least in winter. On the contrary, adventitious rooting was recorded only in culm cuttings in spring and summer season in B. tulda. IBA treatment significantly enhanced rooting, root number and root length; registering 14 to 17 times improvement over control in the best rooting season. Three factor-interactions (season × cutting type × IBA treatment) were significant for rooting in B. nutans and all characteristics, except sprouting in B. tulda. Thus, single-node culm and culm-branch cuttings in B. nutans and culm cuttings in B. tulda treated with 2 mM IBA during spring (February) to summer (May) season are recommended for their clonal multiplication.  相似文献   

11.
Casmara patrona is one of the main borer pests damaging Camellia oleifera in China. Few reports about this insect were published. The life history, biological characteristics and natural enemies of C. patrona were investigated through field survey and laboratory observation in this study. The results showed that C. patrona had one generation in one year or two years, and overwintered as 3rd-5th instar larva in Zhejiang Province. About 88 percent of larvae began to pupate in early May, and the rest kept feeding till the next year. The adults could be observed from early June to early July, and the peak of emergence occurred in late June. The adults began to oviposit in late June and terminated in early July. The eggs started hatching in early July, and then the larvae bored into the branch to feed. The entrance holes of the larvae distributed predominately in the middle of the eastern and southern part of C. oleifera tree. The larva had five instars, and there were 10-50 days when the larva did not feed between consecutive instars.  相似文献   

12.
General biology, seasonal flight numbers and ovipositional data were gathered to understand the phenology of the cherry bark tortrix, Enarmonia formosana Scopoli in Seattle, WA. Pheromone trapping during 2001 and 2002 showed a continuous flight period from May to September. During this time the greatest abundance of adults occurred during July and August. The combined seasonal egg data and larval developmental times indicate E. formosana is a univoltine species in the Pacific Northwest. Field releases of Trichogramma cacoeciae Marchal increased E. formosana egg parasitism on individual trees. During the two years, parasitism levels ranged from 72 to 74%.  相似文献   

13.
绿香、香玲、元林核桃落花落果及果实的生长发育   总被引:3,自引:0,他引:3  
在山东泰安地区对3个核桃早实品种的坐果和果实生长发育过程进行了系统观测,分析了早实核桃落花落果的原因。核桃落果现象主要发生在两个阶段,即核桃青果发育开始前落果和核桃青果发育开始后落果;核桃青果迅速膨大期发生在5月初至6月初,硬核期发生在6月中旬至7月上旬,核桃果仁充实期发生在7月上旬至8月底,核桃果实采收期为8月底至9月初,各阶段具体时间因品种而异;在核桃青果内部结构发育程度上,绿香要早于元林7天左右,香玲早于元林2~4天。  相似文献   

14.
Application ofN 6-benzylaminopurine (BAP) and gibberellin (GA3) to a grafted Japanese red pine (Pinus densiflora Sieb. et Zucc.) clone promoted flowering. BAP (250 mg/l) was sprayed five times to the top of branches in July or September 1992. GA3 (100 or 500 mg/l) was applied five times to the whole plants by spray treatment during the above period, or GA3 solution of the same concentration was injected once into a small incision made in the main stem of clone trees at the beginning of July or the middle of September 1992. In May 1993, no apical female strobili were observed at the top of the new shoots in any treatment. However, lateral female and bisexual strobili were produced in the lower part of new shoots by BAP application in September, regardless of GA3 application. BAP applied in September without GA3 application was sufficient to produce lateral female and bisexual strobili. In such treatment, production of female and bisexual strobili was 47 and 25, and they occurred in 16 out of 68 new shoots, 11 out of 15 treated branches and 5 out of 5 treated trees. The average number of female and bisexual strobili per new shoot was 1.06. BAP treatment either in July or in September significantly decreased (p<0.05) the production of male strobili. These results indicate that BAP application induces the development of lateral female strobili in Japanese red pine when applied during the period of floral differentiation. A part of this paper was presented at the 105th annual meeting of the Japanese Forestry Society.  相似文献   

15.
Seasonal development of resinous stem canker was determined in Chamaecyparis obtusa trees wound‐inoculated with Cistella japonica in January 1996. Samples for anatomical analysis were harvested on 20 May, 9 July and 6 August in the second year of inoculation, and the sections were observed under light microscope. Resin exudation was most abundant in the second year, decreasing in the third. All new resin exudation in the second year was recognized at the May observation. New traumatic resin canal formation was observed in the August samples, and an expansion of necrotic lesions was observed mainly in summer samples in the inoculated trees and in naturally affected trees. Cistella japonica was re‐isolated from all bark lesions or inoculated wounds examined. These results suggest that the activity of Ci. japonica in the tree affects the seasonal development of resinous stem canker during the growing season of the trees.  相似文献   

16.
We assessed seasonal changes of total soluble nonprotein nitrogen compounds (TSNN) in adult European beech trees (Fagus sylvatica, L.) growing under different local climate during the growing season immediately following a thinning treatment and 3 years later. In both years, samples of leaves, xylem sap and phloem exudates from beech trees growing in thinned and unthinned (control) stands on a dry, warm SW exposed and a cooler, moist NE exposed site were collected in May, July and September. In May of both years, asparagine (Asn) and glutamine (Gln) were most abundant in leaves and xylem, respectively, whereas arginine (Arg) dominated in the phloem. In July, TSNN concentrations decreased in all tissues and sites, but differences in water availability between aspects were reflected in TSNN concentrations. In September, differences in the increase of Arg concentration in the phloem were related to differences in the onset of senescence between treatments. Thinning treatment increased amino compound concentrations of beech tissues in July on both aspects, particularly at the NE thinned site. It is supposed that, the N balance of adult beech is favoured by both, the thinning treatments as well as the cool-moist climate prevailing at the NE aspect.  相似文献   

17.
对合欢锈病的发病规律进行了调查研究,在5月上旬和7月底8月初,使用40%福美胂可湿性粉剂和50%甲基托布津可湿性粉剂进行涂干和喷雾防治,效果较好。  相似文献   

18.
Miyake-Jima, a round island of about 8 km in diameter, is located about 200 km south of Tokyo, Japan (34°08′ N, 139°53′ E). In July 2000, the central cone of this island collapsed and a new eruption started with the falling of volcanic ash and SO2 emission. In October 2001, we measured the distribution of bacteria, and Frankia, a symbiotic nitrogen-fixing actinomycete that forms root nodules, and ectomycorrhizal fungi associated with alder in newly deposited ash and its underlying soil by cultivation of Alnus sieboldiana seedlings in these soils. There were fewer bacteria growing on the nutrient broth agar and fewer bacteria growing on 100-fold diluted nutrient broth agar in newly deposited volcanic ash than there were growing in the buried old soil. In four out of five sites, little or no nodulation was observed in newly deposited ash; abundant root nodules were formed in the underlying soil. Ectomycorrhizae formed in the seedlings cultivated in the underlying soil. In May 2003, the distribution of Frankia and ectomycorrhizal fungi in soil at different depths (up to 160 cm) was also investigated. Frankia and ectomycorrhizal fungi were relatively abundant in surface soil layers.  相似文献   

19.
Seasonal variation in the development of chestnut blight, caused by Cryphonectria parasitica, was investigated by inoculating in situ chestnut trees and in vitro excised chestnut segments, at either monthly or 3‐monthly intervals throughout 30 months. Inoculations were made with conidia and mycelium of a virulent isolate and with mycelium of a hypovirulent isolate. Conidial inoculations of living sprouts or excised segments between May and July resulted in the greatest incidence of infection whereas inoculations in autumn and winter, in vitro as well as in situ, did not reveal any visible disease. However, from these symptomless inoculated stems, C. parasitica was isolated 3 months after inoculation. Inoculations with the mycelium of the virulent isolate always resulted in lesions, except in January 1999, and the greatest rate of lesion development occurred for inoculations made in the spring and summer. There was a significant seasonal effect on lesion development. Lesions caused by the hypovirulent isolate, smaller than those caused by the virulent isolate, followed a similar seasonal pattern. The same seasonal variations were observed for inoculations in vitro of excised segments. Relative water content (RWC) of chestnut bark significantly varied with bark sampling date. The rate of lesion development in sprouts significantly correlated with average minimum (ATn) and maximum (ATx) temperatures and the sum of rainfall during inoculation period, with the rate of lesion development measured in excised segments 10 days after inoculation (R10d) and with RWC measured on the day of inoculation. In multiple regression models, variables ATx and R10d best explained variation in lesion development.  相似文献   

20.
Taking Chinese pine in Qianshan Mountains as a sample, the tree ring width chronology including Standard, Residual, and Arstan chronologies was established. The results show that the tree ring width of Chinese pine is highly correlated with the temperatures from May to July and from September to November. Statistically significant positive correlations were observed between tree ring width and the extreme minimum temperatures in July and mean minimum temperatures in September. The chronology was significantly or very significantly correlated with extreme minimum temperatures in December and the following January, with mean minimum temperatures in January, with annual precipitation and with precipitation in April, May and the following December. The Chinese pine responded strongly to the monthly/yearly water vapor pressure and relative humidity. Annual and largely monthly evaporation in April–July had a negative effect on tree growth, and was particularly striking for evaporation in April–July. The narrow tree rings recorded by the chronology demonstrated the 30 occasions of extreme drought since 1800. The growth of Chinese pine in the Qianshan mountains were also affected by climate changes on a hemispheric and global scale. There were 11-, 23-and 50-year-common periodicities between the chronology and solar activity and 10-, 20-and 45-year-common periodicities between the chronology and geomagnetic activity. __________ Translated from Chinese Journal of Applied Ecology, 2007, 18(10): 2191–2201 [译自: 应用生态学报]  相似文献   

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