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柑橘黄龙病（Citrus Huanglongbing,简称HLB）是柑橘的毁灭性病害,柑橘感染后不仅导致叶片黄化,影响果实品质,而且会使树势减弱直至植株死亡。本研究以感染黄龙病和健康沙田柚[Citrus maxima (Burm.) Merr. cv. Shatian Yu]为材料,对比分析黄龙病树（HLB+）和健康树（HLB-）在叶片形态特征、果实品质、矿质元素等方面的差异,旨在掌握黄龙病对沙田柚树体和果实的影响,为促进柑橘黄龙病的防控提供理论参考。沙田柚黄龙病植株与健康植株相比,叶片面积减少28.13%,叶绿素a、叶绿素b和类胡萝卜素分别降低40.38%、44.00%和40.47%;果实外观着色异常且果实偏小,平均单果重下降45.62%,果皮变薄,种子败育增多,果实维生素C升高26.44%,达到显著水平,并且不同组织的多个元素发生显著变化。与健康植株相比,黄龙病叶片N和Ca元素分别减少19.00%和49.72%,果肉N元素减少18.00%,而果皮和果肉Ca元素显著升高;病树根、叶片、果皮和果肉S元素均显著低于健康树。病树叶片B和Cu元素分别降低了35.07%和54.45%,果皮Cu元素显著降低了42.96%,果肉Zn元素显著升高了41.30%。黄龙病严重影响了沙田柚叶片形态和果实品质以及矿质元素代谢,应高度重视提高沙田柚果园的黄龙病防控管理水平。 相似文献
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试验研究了茶园中利用黄(蓝)色粘虫板对茶园害虫的诱捕效果,通过利用黄(蓝)色粘虫板连续对茶园中的主要害虫种类,发生量,时间动态变化以及不同颜色板的诱捕效果情况的分析,结果表明:黄、蓝色板对茶潜叶蝇、茶细蛾、黑刺粉虱、小绿叶蝉、广翅蜡蝉的诱捕效果明显,黄板对小绿叶蝉的诱捕效果比蓝板更佳。8月下旬至9月中旬期间茶园昆虫种类逐渐发生了变化,其中小绿叶蝉在茶园昆虫中所占比例逐渐变少,而黑小壳虫、黑刺粉虱、茶刺蛾相继出现。实验中出现的蜘蛛、瓢虫、蜗牛,寄生蜂类,以及一些数量很少的其他害虫,很有可能是偶然因素被捕获。 相似文献
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以不感染黄龙病植株的柑橘果实作对照，测定轻感染、中感染、重感染黄龙病植株柑橘果实的单果重、可食率、总糖、总还原糖、总酸、Vc、胡萝卜素等理化和营养指标，探究植株黄龙病感染程度对其果实品质的影响。结果表明：植株黄龙病感染对柑橘果实的单果重、可食率无明显影响，黄龙病感染植株其果实中度感染程度的总糖、蔗糖、还原糖含量有所提高，Vc含量随感染程度加深则降低，且均低于对照；重感染植株柑橘果实胡萝卜素含量明显低于对照，而中感染植株果实总酸含量也明显低于对照。这可能与黄龙病感染影响植株和果实糖代谢有关的酶活性、植株叶果比及其所处位置的受光条件等有关。 相似文献
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水稻飞虱对十三种杀虫剂的抗性监测 总被引：7，自引：2，他引：7
1987～1991年选用有机磷、有机氮和拟除虫菊酯类十三种杀虫剂对白背飞虱和褐飞虱用国际统一标准毒力测定点滴法进行抗药性监测。结果表明:1)白背飞虱和褐飞虱对呋喃丹最为敏感,对马拉硫磷敏感度最低。LD_(50)值相差上百倍。因两种飞虱均属迁飞性害虫,年度间的测定结果稍有波动。2)白背飞虱抗药性发展比褐飞虱快,在测定方法和供试昆虫条件基本相同的情况下,将1990年所测几种药剂的LD_(50)与日本Nagata(1967)测定数据进行比较,浙江省白背飞虱种群对马拉硫磷的抗性差异高达110.56倍,对杀螟松为48.90倍;褐飞虱种群对马拉硫磷、杀螟松的抗性分别相差11.61倍和6.11倍。3)褐飞虱种群对药剂的敏感度与当地用药水平呈负相关。4)有机磷类不同品种杀虫剂对两种飞虱的毒力差异较大,毒力较高的久效磷的LD_(50)值与毒力较低的马拉硫磷的LD_(50)相差数十倍。 相似文献
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四种粘板对茶园昆虫的引诱考查 总被引：2，自引：0，他引：2
为评估粘胶色板对茶园昆虫诱捕作用及用于防治主要害虫的可能性,制作了芽绿、橄榄黄绿、素馨黄和雪白色板,于各类昆虫盛发的7月在重庆市郊、浙江松阳县和安徽省麻姑山茶场各0.5βhm2的茶园做了48βh诱捕试验。诱捕的绝大多数昆虫为同翅目害虫;害虫很多而天敌极少,害虫与天敌的个体数量差异极显著。芽绿、橄榄黄绿和素馨黄色板对假眼小绿叶蝉成、若虫和黑刺粉虱成虫的诱效显著大于雪白色板的诱效;从芽绿、橄榄黄绿至素馨黄,绿色色素成分减少、黄色色素成分增多,诱捕的叶蝉数减小而粉虱数增大。可将芽绿、素馨黄色板分别用于叶蝉成、若虫和粉虱成虫的诱捕。 相似文献
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通过筛选获得具有显著促生和抗病能力的AM真菌菌株,为防治柑橘黄龙病提供理论依据和基础,并探索防治新途径。采用盆栽法,于长春花幼苗期分别接种17株AM真菌进行长春花农艺性状和对柑橘黄龙病的抗病性比较试验,研究不同丛枝菌根真菌菌株对长春花的促生效果及对柑橘黄龙病的抑制效果。结果表明,长春花接种AM真菌后,菌株GZ10、GZ5和JX70能显著促进植株生长,其中接种GZ10的株高和茎径分别比CK增加了23.1%和12.1%,接种GZ5的叶片数比CK增加了12.9%;接种菌株GZ1、BNMJ和PWJ有效提高了长春花对柑橘黄龙病的抗病和耐病能力,其相对防效分别为78.39%、66.87%和69.75%。 相似文献
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常规和巢式PCR对柑橘黄龙病菌的检测灵敏度比较 总被引：3，自引：0，他引：3
根据柑橘黄龙病(citrus Huanglongbing,HLB)病菌16SrDNA、16S/23S核糖体基因间隔区(ribosomal intergenic region,RIR)、核糖体蛋白β操纵子(β-operon)和外膜蛋白(out membrane protein,OMP)基因序列设计了8对引物,通过常规和巢式PCR方法对各引物的检测灵敏度进行了比较。结果表明,不同引物的检测灵敏度不同。对于上述任何基因,巢式PCR的灵敏度均比常规PCR至少高103倍;对于同一种基因,扩增短片段的引物比扩增长片段的引物灵敏度高或相当;在扩增产物大小相同时,用以扩增核糖体蛋白β操纵子基因的引物较其他三种稍高。对不同症状柑橘样品的检测进一步验证了该结果。因此,对于柑橘黄龙病的检测,可优先考虑使用巢式PCR方法,若使用常规PCR,则宜选用具有高灵敏度的扩增小片段引物。 相似文献
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为了解小麦干旱对食叶害虫黏虫食物利用效率的影响,采用PEG-6000模拟干旱处理小麦植株,设置对照(0g·mL-1)、低(0.05g·mL-1)、中(0.1g·mL-1)和强(0.2g·mL-1)4个干旱胁迫水平,以盆栽小麦饲喂黏虫幼虫,观察黏虫取食及食物利用效率。协方差分析表明,干旱胁迫对黏虫幼虫的体质量、取食量有显著影响,但对食物利用量没有显著影响。与对照相比,强干旱胁迫下黏虫取食量减少10.4%,幼虫体质量增加量减少10.6%。经食物利用指数方法分析,干旱胁迫显著影响黏虫的近似消化率和食物转化率,强干旱胁迫下食物转化率较对照减小了8.0%,近似消化率增加10.5%;干旱胁迫对其他食物利用指数均无显著影响。以上结果说明,小麦中度和强度干旱胁迫可对黏虫营养利用效率造成不良影响。 相似文献
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Xavier Martini Angelique Hoyte Agenor Mafra-Neto Alexander A Aksenov Cristina E Davis Lukasz L Stelinski 《Journal of insect science (Online)》2020,20(6)
Asian citrus psyllid, Diaphorina citri (Kuwayama), preferentially orient toward citrus hosts infected with the phytopathogenic bacterium, Candidatus liberibacter asiaticus (CLas) the agent of citrus greening (Huanglongbing, HLB), compared to uninfected counterparts. We investigated whether this preference for the odors of infected plants could be useful for the development of an attract-and-kill (AK) device for D. citri. Twenty-nine blends of volatile organic compounds derived from the odor of citrus infected with CLas were tested in laboratory olfactometer tests, and two blends were also assessed under field conditions. A seven component blend of tricosane: geranial: methyl salicylate: geranyl acetone: linalool: phenylacetaldehyde: (E)-β-ocimene in a 0.40: 0.06: 0.08: 0.29: 0.08: 0.06: 0.03 ratio released from a proprietary slow-release matrix attracted twice more D. citri to yellow sticky traps compared with blank control traps. The attractive blend was subsequently co-formulated with spinosad insecticide into a slow-release matrix to create a prototype AK formulation against D. citri. This formulation effectively reduced the population density of D. citri up to 84% as measured with tap counts when deployed at a density of eight 2.5 g dollops per tree as compared with untreated controls in small plot field trials conducted in citrus orchards. Psyllid populations were not statistically affected at a deployment rate of four dollops per tree. Our results indicate that an AK formulation incorporating spinosad and a volatile blend signature of citrus greening into a slow-release matrix may be useful to suppress D. citri populations. 相似文献
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Six types of sticky card traps differing in color and trapping adhesive were evaluated for monitoring Asian citrus psyllid in citrus in the United States (Florida and Texas). We coded the six traps as ASYellow, GLYellow, RWYellow, ASACP, ASGreen and MGGreen. The ASYellow, GLYellow and RWYellow traps were a bright yellow color to the human eye but the yellow color of these traps varied in intensity. To the human eye, the ASACP traps were a lime-green color, the MGGreen trap was a fluorescent yellow-green color, and the ASGreen trap was a green color. Spectral reflectance measurements were taken to categorize the color (wavelength) spectrum of each trap. Percent reflectance in the green and yellow wavelength regions was similar among the ASYellow, GLYellow, RWYellow and ASACP traps. Three of the six sticky traps (GLYellow, RWYellow and MGGreen) were treated with a traditional gluey adhesive material. The other three traps were treated with No Mess Sticky Card™ adhesive, a hot-melted, pressure-sensitive adhesive material. Trapping studies were conducted in Florida and Texas during April–May comparing four of the traps and during September–October comparing all six traps. Data collected during April–May indicated there were no significant differences in numbers of adults captured on ASGreen, ASYellow, ASACP and GLYellow traps. In seven comparisons of all six traps during September–October, the GLYellow and RWYellow traps each captured significantly fewer adults in one comparison, the MGGreen trap captured fewer adults in two comparisons, and the ASGreen trap captured fewer in three comparisons. There was no evidence that any one of the six traps would be best at detecting psyllids when adult populations are scarce. There was no significant difference between the two adhesive materials with respect to numbers of adults captured on traps. 相似文献
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The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important pest of citrus in the United States of America primarily because it vectors ‘Candidatus Liberibacter asiaticus’, the bacterium putatively responsible for Asiatic huanglongbing (HLB). Asiatic HLB is considered one of the most serious diseases of citrus. In the United States where Asiatic HLB was first found in the state of Florida, vector control is considered an essential component to mitigate pathogen infection and spread of the disease. Therefore commercial citrus growers in Florida have adopted intensive insecticide programs to manage psyllid populations. However, the repetitive use of insecticides for ACP control is expensive and interferes with biological control of ACP and other citrus pests. As an alternative to insecticides, reports from Vietnam indicated that infestations of ACP in citrus (and consequently incidence of HLB) were reduced when citrus was interplanted with white guava, Psidium guajava L. Speculations were that guava volatiles reduced ACP infestations in citrus by either repelling ACP or interfering with ACP ability to locate and infest citrus grown next to guava. We present the results of two studies conducted in Florida (where both ACP and HLB occur) to assess ACP infestations and HLB incidence in citrus interplanted with either white or pink guava compared to infestations and disease incidence in citrus grown as a monoculture, both in orchards and nurseries. In the field study, the effect of guava on ACP infestations was assessed alone and in combination with insecticide or oil applications. Significant reductions in ACP infestations in citrus interplanted with pink guava were identified, but there was no reduction in citrus interplanted with white guava. The effect of pink guava on ACP infestations could be investigated further. However, intercropping citrus with either white or pink guava did not prevent the introduction and spread of HLB. Conclusions from field studies regarding guava as a management tactic against ACP were difficult to make due to persistent nematode problems and freeze damage to guava, which could have interfered with the production of guava volatiles responsible for deterring ACP infestations. Conversely, citrus nursery trees interspersed with guava did show reduced HLB incidence and disease progression over time. However, vector and disease reduction resulting from guava intercropping in citrus nurseries was not adequate to recommend it as a management strategy. 相似文献
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Cuban citriculture has recently been affected by important pests and diseases including black citrus aphid Toxoptera citricida Kirkaldy, citrus leafminer Phyllocnistis citrella Stainton, Asiatic citrus psyllid Diaphorina citri Kuwayama, Citrus tristeza disease, and huanglongbing. This complex of ‘invasive species’ is thought to be contributing to the increasing decline of commercial citrus groves. During several surveys carried out in commercial citrus areas of several provinces in Cuba, symptoms of dieback, characterized by the presence of abundant dry branches and wood rot were detected on Criolla Valencia orange, Marsh grapefruit trees on sour orange, and Cleopatra mandarin rootstocks. Samples of branches and trunk wood were processed and a fungus was isolated from all samples. Morphological, physiological and molecular characterization demonstrated that the isolated agent is Fomitiporia maxonii Murrill. The incidence of affected trees was high in most surveyed groves, reaching 100% in old groves. Symptoms similar to the ones found in naturally infected trees were reproduced on trees inoculated with pure cultures of the fungus, and the fungus was recovered in culture from inoculated trees, thus fulfilling Koch's postulates. This is the first report of an association of F. maxonii with citrus wood rot in Cuba. 相似文献
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Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a global pest of citrus and vector of Candidatus Liberibacter, a bacteria that causes huanglongbing or greening, a devastating disease of citrus. Mature citrus trees are dormant in winter and produce most new shoots in spring, followed by sporadic canopy growth in summer and fall. Young shoots are required for oviposition and nymphal development, but adults can survive and overwinter on hardened leaves. Surviving adults reproduce in spring shoots and their progeny are probably responsible for a large portion of disease spread as they disperse to search for food. Therefore, foliar sprays of broad-spectrum insecticides applied to mature trees in winter were evaluated in a commercial citrus orchard as tactic to reduce pest populations and insecticide use in spring and summer when beneficial insects are most active. A single spray of chlorpyrifos (2.8 kg a.i. ha−1) in January 2007 reduced adult psyllids an average of 10-fold over six months compared to untreated trees. The following year, differences with the untreated control averaged 15-fold for over five months following a single spray of chlorpyrifos, fenpropathrin (0.34 kg a.i. ha−1), or oxamyl (1.12 kg a.i. ha−1) applied in January. Spiders, lacewings and ladybeetles were equally abundant during the growing season in both treated and untreated trees both years (P = 0.05). Thus foliar sprays of broad-spectrum insecticides before spring growth suppressed D. citri for five to six months, with no detectible impact on key natural enemies. This tactic has been widely adopted to control the psyllid in Florida, in some cases area-wide. Additional sprays during the growing season should be based on scouting and targeted at adults before anticipated new flush. 相似文献
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Soil application of systemic neonicotinoid insecticides for control of psyllid vectors of Huanglongbing disease on young citrus trees also produces season-long SAR control of citrus canker caused by Xanthomonas citri subsp. citri Schaad et al. The neonicotinoids imidacloprid (IMID) and thiamethoxam (THIA) were compared with soil or sprinkler applications of the commercial SAR inducer acibenzolar-S-methyl (ASM) and foliar sprays of copper hydroxide (CH) and/or streptomycin (STREP) to evaluate their effects on the percentage of canker-infected leaves on 2-yr-old ‘Vernia’ orange and 3-yr-old ‘Ray Ruby’ grapefruit trees in Southeast Florida. All treatments significantly reduced the incidence of foliar canker compared to the untreated check. Soil drenches of ASM and season long rotations with IMID and THIA were highly effective for suppressing foliar canker on young grapefruit and orange trees under weather conditions absent of high intensity rains or tropical storms. Sprinkler application of ASM was less effective than soil drench. The level of control for SAR treatments was comparable to eleven 21-day interval sprays of CH and/or STREP. SAR induced by soil-applied insecticides provides substantial benefits for canker disease management on young citrus trees that may be augmented with ASM. 相似文献
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Casey D. Butler Beatriz GonzalezKeremane L. Manjunath Richard F. LeeRichard G. Novy J. Creighton MillerJohn T. Trumble 《Crop Protection》2011,30(9):1233-1238
The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a major pest of potatoes that can cause yield loss by direct feeding on crop plants and by transmitting a bacterial pathogen, Candidatus Liberibacter psyllaurous (a.k.a. Candidatus Liberibacter solanacearum) associated with zebra chip disease of the crop. In recent years, there have been no studies regarding resistance of potato to the potato psyllid or the bacterial pathogen that the psyllid transmits. Thus, the objectives of this study were to determine the effects of potato germplasm on adult potato psyllid behavior and transmission of Ca. L. psyllaurous. A total of twenty-two potato (Solanum tuberosum L.) breeding clones and varieties were examined. Plant genotype significantly affected the occurrence and duration of psyllid probing, the duration of psyllid cleaning, resting and the amount of time psyllids spent off the potato leaflet as well as transmission of Ca. L. psyllaurous. For the potato genotypes in which there were significant decreases in transmission compared to controls, there was often an unclear relationship between the occurrences and duration of behaviors and subsequent bacterial transmission. We discuss the implications of our results for an integrated pest management program for the potato psyllid and Ca. L. psyllaurous control on potatoes. 相似文献
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Sterile insect release (SIR) for control of insect pests focuses on release of sterile individuals within the focal crop. Its success is related to the extent to which pest individuals are concentrated in the crop or spread out across the landscape mosaic. However, little is known of the success of SIR relative to spatial densities of target insect pest populations. This is especially so for the false codling moth (FCM) Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), an indigenous moth to Africa and one of considerable phytosanitary significance. The aim here was to establish densities of the moth across a citrus production landscape in South Africa where the pest is particularly significant. Pheromone-baited delta traps were laid out in transects across a commercially important citrus-producing valley to assess the spatial and temporal distribution of wild males, prior to implementation of a commercial SIR programme. Transects included the focal citrus orchards, while also including a range of natural habitat types and elevation gradients. Male FCM were mostly confined to the citrus orchards, while those outside were close to citrus orchards or in alien alternative host plant patches, with only a few male individuals being caught up to 1.5 km from the nearest orchard. This suggests that the indigenous vegetation is supporting only a low FCM population, while, in contrast, citrus orchards are the main reservoir for FCM populations. These findings emphasize the importance of focussing SIR for FCM within the crop and on other, adjacent alien host plants, and not to dissipate releases into the surrounding and extensive natural vegetation. 相似文献
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The Asian citrus psyllid, Diaphorina citri Kuwayama being a vector of huanglongbing (HLB), citrus greening disease is the most destructive pest of citrus and the management of D. citri is crucial for successful control of HLB. We evaluated adult populations of D. citri from twelve districts of Punjab, Pakistan for resistance to seven different insecticides. Different levels of resistance ratios were observed for all insecticides (chlorpyrifos, bifenthrin, imidacloprid, acetamiprid, thiamethoxam, nitenpyram and chlorfenapyr). Field collected populations of D. citri were highly resistant to imidacloprid as compared to the susceptible population. The resistance ratios were in range of 236.6–759.5, 55.5–212.8, 13.1–46.4, 31.4–216.7, 8.6–89.4-fold for imidacloprid, acetamiprid, chlorfenapyr, nitenpyram, and thiamethoxam, respectively and 39.8–107.1 and 32.7–124.5-fold in case of conventional insecticides i.e., bifenthrin and chlorpyrifos, respectively. Nitenpyram and thiamethoxam, with no or very low resistance should be used in combination or in rotation with other pest management tactics for managing resistance in D. citri. The correlation analysis of the LC50's of insecticides showing positive and negative correlations among different insecticides in all tested populations, suggests mechanism of cross-resistance. Imidacloprid showed a positive correlation with acetamaprid, but a negative correlation with thiamethoxam from the neonicotenoid group, while the resistance to chlorfenpyr positively correlated with chlorpyrifos and bifenthrin in the pyrethroid group. Multiple resistance mechanisms could be the reason behind the development of such a high resistance in the D. citri. 相似文献