首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   24篇
  国内免费   1篇
  完全免费   24篇
  2021年   2篇
  2020年   5篇
  2019年   3篇
  2018年   1篇
  2017年   8篇
  2016年   4篇
  2015年   3篇
  2014年   2篇
  2013年   4篇
  2012年   4篇
  2011年   2篇
  2010年   1篇
  2009年   1篇
  2008年   1篇
  2007年   2篇
  2005年   1篇
  2004年   1篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1989年   1篇
排序方式: 共有49条查询结果,搜索用时 46 毫秒
1.
Given the apparent importance ofladybeetles as biological control agents of theinvasive Asian citrus psyllid, Diaphorinacitri Kuwayama (Homoptera: Psyllidae), aseries of experiments were undertaken to assessthe nutritional suitability of this pest as aprey item. Five species of Coccinellidae wereshown to develop successfully on a diet ofpsyllid nymphs and four species produced viableeggs. Eggs of the flour moth, Ephestiakuehniella Zeller (Lepidoptera: Pyralidae)were used as a reference diet. Larvae of Curinus coeruleus Mulsant, Cyclonedasanguinea L., Exochomus childreniMulsant, Harmonia axyridis Pallas, andOlla v-nigrum Mulsant all had survival ona diet of D. citri nymphs not differentfrom 100%, although developmental times wereextended and adult dry weights were reducedrelative to the Ephestia egg diet. Species were ranked (highest to lowest) forlarval performance on the D. citri dietrelative to the Ephestia egg diet as:E. childreni, 0.85;O. v-nigrum,0.82; C. coeruleus, 0.80;H.axyridis, 0.71;C. sanguinea, 0.48. Most females of C. sanguinea ceasedoviposition on the second day followingtransferal to the D. citri diet, but thefecundity and fertility of females of the otherspecies were not different from those feedingon Ephestia eggs. Generation times onthe Ephestia egg diet at 24°C(time to egg hatch + larval developmental time+ pupation time + adult prereproductive period)were (mean ± SEM): C. coeruleus, 56.7± 1.32 d;C. sanguinea, 28.0 ±0.88 d;E. childreni, 60.8 ± 1.96 d;H. axyridis, 32.2 ± 1.47 d;O.v-nigrum, 25.8 ± 1.12 d. Adult females ofC. coeruleus, H. axyridis and O.v-nigrum consumed the most psyllids in oneh, C. sanguinea was intermediate, andE. childreni consumed the least.  相似文献
2.
光、温湿度对柑桔木虱发育、繁殖与存活的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
杨余兵 《生态学报》1989,9(4):348-354
本研究结果表明,在光照强度为11000lx以下(6小时光照时为15000lx)、每天光照时间在18小时以内,光照强度越大,光照时间越长,柑桔木虱雌成虫的产卵前期越短,产卵量越大,死亡率越低。 温度为15—34℃,相对湿度为43—92%范围内,温湿度对柑桔木虱卵的孵化率影响较小。柑桔木虱若虫在高温(34℃)、高湿(85%,92%)下死亡率高;适温(20—30℃)、低湿(43—75%)下死亡率低。湿度对柑桔木虱卵及若虫发育历期影响不大。在温度为15—34℃范围内,温度与卵及若虫的发育历期呈抛物线关系。柑桔木虱卵及1—5龄若虫的发育起点温度分别是:9.41℃、8.30℃、9.72℃、8.92℃、9.61℃及9.07℃,有效积温分别是:60.03日度、39.78日度、26.82日度,33.23日度及74.49日度。  相似文献
3.
The production of biological insecticides requires the identification and selection of candidate isolates of entomopathogenic fungi (EPF). The objective of this study was to characterise by virulence factors, single-spore strains of the CHE-CNRCB 303, 305, 307 strains initially identified as Isaria fumosorosea and the 224 strain of Metarhizium anisopliae to identify those with outstanding quality parameters that can serve to improve the control programme for Diaphorina citri (Hemiptera: Liviidae) in Mexico. The size of conidia and phialides was evaluated. The internal transcribed spacers established molecular identity. The selection of single-spore strains was done using radial growth (RG), the production of conidia (PC) and germination (G) rates. Principal component analysis (PCA) was used to determine the correlation between the variables and as screening criterion. Molecular and morphometric analysis confirmed that isolates 303, 305 and 307, and their single-spore strains correspond to the Isaria javanica species. The 224 strain and its single-spore strain were identified as M. anisopliae sensu lato. The statistical analysis of the RG, PC and G variables showed significant differences (P ≤ 0.05) between single-spore strains and their multi-spore strains. PCA showed a correlation between the RG and PC. The assay with Pr1 proteases associated with the surface of the conidia showed significant differences (P ≤ 0.05) for single-spore strains of I. javanica 303/2, 305/1 and 305/5 compared to the original strains. The characterisation of genetically homogeneous populations of EPF will allow us to obtain improved isolates, which are needed for the mass production of mycoinsecticides.  相似文献
4.
The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is an important invasive citrus pest in the USA because it vectors a bacterium responsible for huanglongbing, a devastating disease of citrus. Information was lacking on seasonal aspects of flight activity by D. citri, which could have ramifications on psyllid management as well as our understanding of epidemiology of the disease. Of interest from a pest management standpoint would be whether D. citri regularly disperses to or away from citrus on a predictable schedule. In research presented here, seasonal flight activity by D. citri was investigated using yellow sticky traps deployed in citrus trees and in fallow areas adjacent to citrus. Results indicated that flight activity by both male and female D. citri away from citrus can occur at any time of the year with consistent dispersal activity during the spring. The research further indicated citrus is continually subject to infestation by immigrating adults and that there is no time during the year that a citrus grower could be assured immigration would not occur. Growers should be aware that adult dispersal occurs regularly during spring and they should time management tactics accordingly. Adult flight activity 2 m from a citrus tree was more pronounced at 1 m above ground than at 2 or 3 m high. At distances of 8–60 m from trees, numbers of adults on traps were similar among the three heights. Males and females were similar with respect to seasonal flight activity. Numbers of adults captured on traps distant from citrus were not correlated with wind speed, sunlight, or air temperature, but there was some evidence that relative humidity influenced flight activity. Although the D. citri life cycle is dependent on flush, data from these studies did not confirm that psyllid dispersal from citrus consistently increases as citrus flush abundance decreases.  相似文献
5.
基于16S rDNA序列的柑桔木虱体内共生菌多样性研究   总被引:1,自引:0,他引:1       下载免费PDF全文
昆虫消化道内是一个复杂的微生态系统, 有大量的微生物存在。这些微生物对寄主发育、 营养吸收和防御方面都起着重要的作用。本文利用基于16S rRNA基因的PCR-RFLP指纹图谱法和变性梯度凝胶电泳(denaturing gradient gel electrophoresis, DGGE)的方法对柑桔黄龙病虫-媒柑桔木虱Diaphorina citri体内细菌菌群多样性进行了研究。经PCR-RFLP分析显示31条序列与变形菌门的假单胞菌科、肠杆菌科、黄单胞菌科、伯克氏菌科、立克次氏菌科和根瘤菌科细菌具有较高同源性。柑桔木虱内共生细菌的优势菌群依次为合胞体共生菌(syncytium endosymbiont)(同源性99%, 5条序列, 分离频率31%)、 Candidatus Carsonella ruddii和Mycetocyte 内共生菌(同源性98%, 5条序列, 分离频率31%)以及亚洲韧皮杆菌(Candidatus Liberibacter asiaticus)和内共生菌Wolbachia。对柑桔木虱内生细菌16S rDNA V3区序列的PCR-DGGE分析, 条带相似性的UPMAGA聚类分析表明, 采自九里香Murraya paniculata的柑桔木虱内生细菌大多聚为一支, 而来自柑桔的聚在另一支, 说明寄主差异对柑桔木虱内生细菌菌群构成的影响大于地理位置的影响。将PCR-DGGE条带测序, 序列经GenBank序列比对发现柑桔木虱内生细菌主要属于变形菌门假单胞菌科、 立克次氏菌科、 肠杆菌科、 黄单胞菌科以及厚壁菌门链球菌科和芽孢杆菌科。合胞体共生菌(条带3-4)因其稳定存在于木虱体内且不随柑桔木虱寄主和地理位置的改变而变化, 可能是柑桔木虱体内的优势共生菌; 内共生细菌Wolbachia也在柑桔木虱内稳定存在, 表明我国柑桔木虱感染Wolbachia是普遍现象。PCR-RFLP和PCR-DGGE两种方法相结合较好地反映了柑桔木虱内生细菌菌群的多样性, 而且均显示出柑桔木虱内的合胞体共生菌是主要的优势菌群。  相似文献
6.
The accidental importation of plant pathogens in or on the bodies of parasitoids imported as natural enemies has been raised as a potential risk of classical biological control projects involving insects that serve as vectors of plant diseases. During quarantine evaluation of two parasitoids, Tamarixia radiata Waterston and Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal), imported for classical biological control of Asian citrus psylla Diaphorina citri (Kuwayama) in Florida, we were asked to determine whether these parasitoids were free of the causal agent of Asian greening disease, the bacterium Liberobacter asiaticum. Preliminary tests with allele-specific polymerase chain reaction (Standard PCR) suggested that the assays were prone to false negatives. Another PCR protocol, Long PCR, previously was shown to be more reliable than Standard PCR for screening of insects for another bacterium (Wolbachia). The sensitivity of Long and Standard PCR protocols was compared by use of plasmid DNA containing two DNA fragments from the greening disease agent or plasmid mixed with DNA extracted from host plants, psyllids, or parasitoids. Results indicated that inhibitors of the PCR were present in both plant and insect DNA, making the Standard PCR relatively insensitive and allowing high levels of false negatives. Long PCR, which incorporates a second DNA polymerase with proof-reading activity, yielded consistent results and was orders of magnitude more sensitive than the Standard PCR. As few as 100 copies of plasmid mixed with either plant or insect DNA consistently could be detected. Long PCR assays conducted on pooled and individual T. radiata and D. aligarhensis, their psyllid hosts, or their host plants over a period of 6 months failed to produce any positives, indicating that release of these two parasitoids should elicit little concern that greening bacteria would be introduced accidentally into Florida through this classical biological control program.  相似文献
7.
柑砧术虱是柑桔新梢期重要害虫,刺吸为害。福建福州在柑桔上一年发生8代,在月桔、九里香上一年约发生10代左右,世代重叠,以成虫在柑桔叶背群集越冬,无完全滞育。4—5月气温22.3℃世代历期42.5天.6-7月27.2℃为24.4天.8月28.1℃为23.2天。10-12月19.6℃为52.9天。成虫寿命长,约历1个月半,越冬代长达半年。田间种群消长与柑桔芽梢抽发期相对应.一年中虫口数量出现3个高峰期,第一峰期3-4月为柑桔春梢主要抽发期,第二峰期5-6月为夏梢主要抽发期,第三峰期8~9月为秋梢主要抽发期,其中以秋梢期虫口数量最大.秋芽受害最重,次为春梢期。本还对柑桔术虱天敌进行调查,并对柑桔术虱卵、若虫和成虫进行药剂防治试验。  相似文献
8.
In an attempt to suppress the propagation of citrus greening disease in Indonesia, we explored pathogens ofDiaphorina citri which vectors the disease. At two orange orchards, manyD. citri adults were found to be dead and covered with fungal mycelia. Two fungi,Paecilomyces fumosoroseus andHirsutella citriformis, were consistently isolated from the infected insects. Molecular phylogeny of their 18S rDNA sequences showed that they belong to the ascomycetous clade of the Clavicipitales/Hypocreales, which embraces many entomopathogenic fungi. When healthy adults ofD. citri were inoculated with conidia of theP. fumosoroseus, the insects died within 6 d.  相似文献
9.
【目的】亚洲柑桔木虱Diaphorina citri Kuwayama的虫口密度及活动与柑桔黄龙病的田间传播、流行有十分密切的关系,寻找合适的室内饲养条件能够便于观察和研究其生物学特性和传病机制。【方法】本文以九里香Murraya exotica (L.) Mant.、酸桔Citrus sunki Hort. ex Tanaka和马水桔Citrus reticulata Blanco. cv. Mashuiju 3种寄主植物不同成熟度离体梢为研究材料,(1)比较亚洲柑桔木虱卵分别在3种寄主植株和离体嫩梢上的孵化率;(2)比较3种寄主不同成熟度离体梢对各龄若虫存活率和蜕皮的影响;(3)比较3种寄主不同成熟度离体梢对成虫存活率的影响。【结果】(1)亚洲柑桔木虱在植株嫩梢上卵的孵化率高于离体嫩梢,九里香表现最明显;(2)低龄若虫在叶片未完全展开的离体嫩梢上存活率最高,而高龄若虫在完全展开的嫩梢上最高;(3)用离体成熟梢饲养柑桔木虱成虫存活率高于离体嫩梢,酸桔和马水桔离体梢饲养的存活率较九里香高。【结论】用寄主植物离体梢饲养的亚洲柑桔木虱卵孵化率和若虫、成虫存活率都较高而且较稳定,该方法可用于这种木虱的室内繁殖中。  相似文献
10.
吴丰年  梁广文  岑伊静  高娃 《昆虫知识》2013,50(4):1085-1093
亚洲柑桔木虱Diaphorina citri Kuwayama为黄龙病的媒介昆虫.本文研究了其雌雄成虫在刚羽化、羽化后3 h、交配盛期和产卵盛期的腹部和前翅颜色变化规律,明确了每个时期的主要体色,同时探讨了不同季节、虫口密度和寄主条件对体色变化的影响.结果表明,雌雄木虱羽化后前翅颜色均由白色→黑色→红褐色渐变,木虱雌成虫腹部颜色随时间推移由黄绿色→灰白色→蓝色→橙色渐变,雄虫由黄绿色→灰黑色→橙色渐变.季节、寄主和虫口密度的变化对雌虫腹部颜色构成有一定的影响,但对雄虫基本上没有影响.不同条件下雌虫腹部的主要颜色为蓝色或橙色,雄虫均以橙色为主,其次为灰黑色,表明木虱成虫多处于交配期或产卵期.木虱5龄若虫的体色变化也较大.多数条件下木虱的性比接近于1:1,仅春秋季雌性比例略低于雄性.通过观察木虱的体色变化规律可以初步判断其羽化情况和性别,估计羽化期、交配期和产卵盛期,作为木虱生物学特性研究和预测预报的参考.  相似文献
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号