柑橘全爪螨空间格局与抽样技术的研究

本应用空间分布型统计参数IwaoM-X模型中α,β及6个聚集指标分析了柑橘全爪螨的空间格局,并对抽样技术进行了探讨。结果表明,柑橘全爪螨的空间格局为聚集型;田间的抽样部位是上、中、下三部的叶片。提出了估算柑橘全爪螨在不同虫口密度下的理论抽样数。     

竹裂爪螨自然种群消长及空间格局研究

本文对毛竹害螨优势种竹裂爪螨Schizotetranychus bambusae Reck自然种群在主要发生季节的消长情况进行了调查。结果表明,竹裂爪螨在林间发生的高峰期为5—6月份。发生的严重度与林份条件有密切关系,在土壤瘠薄、林相较差的林区发生重;海拔较高、人为干扰度大的林区的发生重且高峰有所延后。竹裂爪螨在林间不同年龄竹株上存在转移危害,即4—5月,3年生竹上(当年不换叶)的有螨叶率与平均每叶螨量大于2年生竹;5月下旬以后,2年生竹换叶完成、新竹开始上林,竹裂爪螨逐渐转移到新叶上为害,使得在1年生竹、2年生竹上的发生量逐渐超过3年生竹上的发生量。通过对5、6月发生高峰期的空间格局研究表明,竹裂爪螨在毛竹林间呈聚集分布,且密度越高,聚集度越大。利用Iwao的m-m回归分析表明,竹裂爪螨是以个体群的方式存在。从空间格局的动态规律上看,5月份的聚集度大于6月份的聚集度,其中5、6月份的m'-m回归式分别为：m＝2．265 2．342m(R＝0．853,5月份)、m＝1．612 2．171m(R＝0．952,6月份)。     

苹果全爪螨的空间分布格局及时序动态

苹果全爪螨是影响我国苹果生产的重要害虫之一.为明确其在苹果树冠上的时空格局,在2007年5-11月整个生长季节,采用不同方位、不同层面随机取样的方法调查害螨数量.应用聚集度指标法和Iwao回归测度法分析苹果全爪螨在苹果树上的分布型及其变化动态.结果表明:苹果全爪螨在苹果树冠整体范围内前期和中期符合负二项分布,呈聚集型,基本成分为个体群,且个体间相互吸引.聚集强度随种群密度的消长而波动,表现出高密度、低聚块及低密度、高聚块的规律,并且在树冠的不同方位和不同层面上存在一定差异:个体群的聚块性南部最高,西部最低;树冠中、下层高于上层,内层高于外层.     

叶面肥对柑橘全爪螨生长发育和繁殖及柑橘苗生长的影响(英文)

【目的】柑橘全爪螨Panonychus citri在中国是一种重要的柑橘害虫,叶面肥在橘园的应用很普遍。本研究是为了明确柑橘施用尿素和复合氨基酸2种叶面肥对这种害螨生长发育和繁殖及柑橘苗生长的影响。【方法】在室内分别用尿素(0.50%)和复合氨基酸(0.17%)2种叶面肥喷施盆栽沙糖橘Citrus reticulata Blanco cv. Shatangju苗,以喷施清水为对照,探究叶面施肥对柑橘全爪螨生命表参数［净 增殖率(R₀)、平均代时(T)、内禀增长率(r_m)、周限增长率(λ)和种群趋势指数(I)］及柑橘苗生长参数(叶长、宽和面积, 茎长, 株高, 新梢的长度和数量)和叶片养分(N, P和K)含量的影响。【结果】柑橘全爪螨未成熟螨态的发育历期没有受到叶面肥的影响,但施用0.50%尿素的柑橘苗上第2若螨的存活率(95.40%)显著高于施用清水的对照(78.26%)和喷施0.17%复合氨基酸的处理(75.61%),其雌螨的繁殖力(42.1/♀)也显著高于对照(33.1/♀)。复合氨基酸处理柑橘苗上的雌螨寿命(19.5 d)显著长于尿素处柑橘苗上的雌螨寿命(14.8 d)和对照(14.5 d),复合氨基酸处理柑橘苗上的雄螨寿命(17.6 d)也显著长于对照(13.1 d)。总体上,在尿素处理的柑橘苗上柑橘全爪螨的净增殖率(R₀)(17.88)和种群趋势指数(I)(18.08)值最高,2个参数都显著高于对照(分别为10.08和11.17)。施用2种叶面肥显著促进了柑橘苗叶片生长(叶长、叶宽、叶面积),其N, P和K含量以及氮钾比(N/K)也显著增加。【结论】柑橘苗叶面喷施尿素和复合氨基酸都可促进柑橘苗生长,喷施尿素会导致柑橘全爪螨种群的显著增长,而喷施复合氨基酸没有导致柑橘全爪螨种群显著增长。因此,推荐使用复合氨基酸代替尿素作为柑橘的叶面肥施用。但是,喷施复合氨基酸可显著延长柑橘全爪螨成螨的寿命,所以在使用时还应该加强对其种群的监测。     

江西南昌柑橘冠层节肢动物群落组成及时序动态研究

采用叶面观察和诱捕相结合的方法调查了江西南昌柑橘冠层节肢动物群落。共调查到节肢动物数量144037头,分属25种。其中,高密度种类有2种即柑橘全爪螨和矢尖蚧;常见种类有13种,包括桔小实蝇、柑橘花蕾蛆、柑橘木虱和中华草蛉等;其它为低密度种类。在群落结构指数的变化过程中,分别于5月下旬和9月下旬出现Shannon-Wiener多样性指数极大值和Simpson优势度指数极小值。对高密度种类和部分常见种类的种群动态进行了分析,表明柑橘全爪螨在5月下旬至6月上旬发生严重,矢尖蚧则于7~8月发生严重;柑橘花蕾蛆幼虫和柑橘木虱发生动态相似,均仅于柑橘春梢阶段出现最高密度;桔小实蝇成虫则在9月下旬出现密度高峰;中华草蛉的发生动态与其主要捕食对象—柑橘全爪螨的相似。研究结果初步明确南昌柑橘冠层节肢动物的重要成分及重要类群的时序动态,为该地区柑橘重要害虫的防治与控制,天敌昆虫的保护与利用提供基础信息。     

华北平原地区景观格局对麦田害螨种群数量的影响

农业生产的集约化经营导致农田景观格局日趋单一,而农田景观格局的变化势必对害虫种群产生深刻的影响,阐明景观因子对害虫种群的作用是通过生境管理进行害虫控制的基础。以华北平原地区的山东省为研究区域,24个县级单元为样点,通过对卫星遥感影像和土地覆盖分类数据的分析,获取了样点单元的景观格局指数,同时定点调查了样点单元的麦田害螨种群数量。利用相关性分析明确了影响麦田中两种害螨—麦岩螨(Petrobia latens(Müller))和麦圆叶爪螨(Penthaleus major(Duges))种群发生的主要景观因子。研究结果表明景观因子对麦田中两种害螨种群均有显著影响,而两种害螨对景观因子的响应并不一致。麦岩螨的发生量与森林的最大斑块面积指数和平均斑块面积均呈显著正相关,而与森林类的形状和水体的景观形状指数均存在显著负相关;麦圆叶爪螨的发生量同水体的总面积、斑块面积比例、最大斑块面积指数以及县域范围的平均斑块面积均呈显著负相关,而与水体类的形状呈显著正相关。因此在麦田害螨发生较重的地区,在区域性景观规划时,可以通过优化农田周围的森林和水体管理,不利于其种群发生,从而达到对麦田害螨种群生态调控的目的。     

柑橘全爪螨田间种群敏感性测定及三种主要解毒酶活性比较

为明确重庆地区柑橘全爪螨Panonychus citri(McGregor)对常用杀螨剂的抗性水平,本研究采用阿维菌素、哒螨灵、三唑锡、螺螨酯4种不同类型杀螨剂对柑橘全爪螨重庆北碚种群、璧山种群、武隆种群和忠县种群进行了田间敏感性测定。结果表明,柑橘全爪螨4个种群对三唑锡表现最不敏感,致死中浓度LC50在209.9～370.9mg/L之间。璧山种群对阿维菌素敏感性最高,武隆种群和忠县种群对阿维菌素的相对抗性分别达12倍和11倍。哒螨灵监测结果表明,北碚种群的抗性水平显著高于其他3个种群。而北碚种群对螺螨酯的LC50仅为1.2mg/L,显著低于其他种群。柑橘全爪螨4个种群解毒酶活性研究发现,解毒酶活性的高低与不同种群抗性水平之间并没有明显相关性,这可能同各地区施药背景不同、综合防治措施不同、各杀螨剂作用机理不同、不同种群体内代谢抗性及靶标抗性水平差异有关。     

棉蚜及龟纹瓢虫空间格局的地学统计学研究

应用地学统计学的原理和方法研究了不同时期棉蚜及龟纹瓢虫种群的空间结构和空间生。结果表明,不同时期棉蚜种群的关变异函数曲线皆为球型,其空间格局为聚集型,变程在８．２１￣１０．８１ｍ之间;龟纹瓢虫种群的拟合半变异函数曲线也表现为球型,呈聚集空间格局,空间变程在８．０１￣１４．２５ｍ之间,并与棉蚜种群在数量和空间上有较强的追随关系,说明龟纹瓢虫种群是棉蚜种群的优势种天敌。     

橘园中重要天敌具瘤神蕊螨与其主要猎物的生态位

研究了柑橘园中具瘤神蕊螨(Agistemus exsertus)与其主要猎物柑橘皱叶刺瘿螨(Phyllocoptruta oleivora)、柑橘全爪螨(Panonychus citri)、柑橘粉虱(D ialeurodes citri)、黑刺粉虱(Aleurocanthus spiniferus)的生态位宽度、重叠和比例相似性。具瘤神蕊螨与其主要猎物相比,其时间和空间生态位宽度均最大,而其猎物中则以柑橘皱叶刺瘿螨的时间和空间生态位宽度最大,这表明具瘤神蕊螨和柑橘皱叶刺瘿螨的发生期较长,空间分布较广。具瘤神蕊螨与其猎物的生态位重叠在空间上与柑橘全爪螨的重叠值最大,在时间上与柑橘粉虱的重叠值最大。与其猎物相比,具瘤神蕊螨的时—空二维生态位宽度最大,在时空上占有明显的优势。     

苹果园二斑叶螨种群的空间格局

种群空间格局的研究是昆虫生态学的重要内容,它不仅揭示出种群的空间结构特征,而且还是确定抽样技术和资料代换的基础,二斑叶螨是苹果园的重要害螨,应用4种聚集度指标和Iwao法分别考查了该螨在苹果树内的空间格局及动态规律,结果表明,二斑叶螨在树内不同方向和高度上均以个体群的形式存在,个体群的分布为聚集分布,其中上层和南面树冠的聚集度最高,而下层和内部树冠的聚集度最低,造成这种差异与该螨的生物学特性和环境条件的异质性有关,不论螨体在上层,中层或下层树冠,都明显地表现出前期高聚块,6月中旬以后聚集强度逐渐降低的趋势。     

不同柑桔品种上桔全爪螨的生长和种群动态差异

通过田间调查、室内盆栽苗接螨、离体叶片饲养等方法,考察了14个柑桔品种上桔全爪螨种群动态,组建了其实验种群生命表,结果表明：该螨在各柑桔品种上的种群密度有明显差异,平均密度以北碚447、台湾晚白柚和垫江白柚上较高,柑新生系最低。雌成螨寿命在台湾晚白柚上最长,垫江白柚次之,柑新生系最短;产卵量以取食台湾晚白柚时最多,垫江白柚、五步红心柚次之,以柑新生系最少;在垫江白柚上的内禀增长率（r_m）最大,沙田柚、台湾晚白柚次之,金弹最小。根据桔全爪螨实验种群的参数判断,金弹和柑新生系属抗螨品种,台湾晚白柚、垫江白柚和北碚447是感螨品种。从品种归类上来看,柚类品种和甜橙中的北碚447感螨程度较高,金柑属的金弹和宽皮柑桔类的柑新生系感螨程度较低。甜橙类与宽皮柑桔类比较,前者感螨程度较高,后者相对较低,但宽皮柑桔类的早津感螨程度相对较高。     

Monitoring the susceptibility of citrus rust mite (Acari: Eriophyidae) populations to abamectin.

A citrus leaf disk bioassay was developed to monitor the susceptibility of citrus rust mite, Phyllocoptruta oleivora (Ashmead), populations to abamectin. Disks from leaves of several citrus cultivars were equally suitable bioassay substrates, and there was no difference in mortality when mites were sprayed directly or exposed to dry abamectin residue. The concentration-response relationship was determined at intervals over 2 yr for a reference population of citrus rust mites that had been maintained in culture and never exposed to acaricides. Three diagnostic concentrations of abamectin were selected based on the response of the reference population and were used to test the susceptibility of 15 populations of mites from commercial citrus groves. Comparisons with the reference population showed reduced levels of susceptibility in some populations. Populations of citrus rust mites from 6 commercial groves were sprayed twice in 1997 with combinations of acaricides designed to exert different intensities of selection pressure from abamectin. None of these populations showed a change in their response to abamectin in pre- and postspray bioassays, although their susceptibility was usually less than that of mites from the susceptible reference population. Biweekly counts of rust mites on fruit in these 6 groves suggested that, relative to groves which received no abamectin or 1 abamectin spray, mite control was not adversely affected in the groves sprayed twice with abamectin. The bioassay method is discussed in relation to factors that affect the interpretation of results from its use, and factors that may affect the development of resistance to abamectin in citrus rust mite populations are presented. This study has provided baseline data with which the results of ongoing tests of the response of citrus rust mite populations to abamectin can be compared.     

Seasonal occurrence of key arthropod pests and associated natural enemies in Alabama Satsuma citrus

Six Alabama Satsuma mandarin orchards (four conventionally sprayed and two unsprayed) were surveyed during 2005 and 2006 to determine the population dynamics of arthropod pests and their natural enemies. Twenty-eight arthropod pest species were encountered; the major foliage pests were citrus whitefly, Dialeurodes citri (Ashmead); purple scale, Lepidosaphes beckii (Newman); Glover scale, L. gloveri (Packard); and citrus red mite, Panonychus citri (McGregor). Two distinct population peaks were recorded for citrus whitefly at most locations. The most important direct sources of citrus whitefly mortality were parasitism by Encarsia lahorensis (Howard) and infection by the pathogenic fungus, Aschersonia aleyrodis Webber. In general, all stages of both scale insects (purple scale and Glover scale) were present in the orchards year-round, indicative of overlapping generations; however, the highest densities were recorded during the early season. Citrus whitefly, purple scale, and Glover scale were more abundant on leaves collected from the interior of the tree canopy than in the exterior canopy. Citrus red mite densities were highest in the spring, with populations declining at the start of the summer, and were more abundant in the exterior canopy than in the interior canopy. The most important natural enemies of citrus red mite were predatory mites belonging to several families, of which Typhlodromalus peregrinus Muma (Phytoseiidae) was the predominant species. Major differences were recorded in the relative abundance of different arthropod pest species in the orchards: citrus whitefly, purple scale, and Glover scale predominated in the unsprayed orchards, whereas citrus red mite infestations were more severe in the sprayed orchards. The results are discussed in relation to the possible effect of orchard management practices on abundance of the major pests.     

SEASONAL PERFORMANCE AFFECTING POPULATION DYNAMICS OF CITRUS RED MITE, FANONYCHUS CITRI (MCGREGOR) (ACARI: TETRANYCHIDAE), ON PEAR

Abstract The population of the citrus red mite, Panonychus citri (McGregor), does not increase on pear from spring to mid-summer but thereafter increases abruptly. To elucidate this phenomenon, we compared the performance of the mites on pear leaves with that on citrus leaves, at different time throughout the pear-growing season. No significant difference was detected between the oviposition rate on pear and that on citrus throughout the season. However, the survival rate of ovipositing females that had fed on pear and the hatch rate of eggs laid by those females were significantly lower than those for females that had fed on citrus, until August. However, no significant difference was observed thereafter. The results showed that the decline of the population of citrus red mite before autumn is due to the high mortality of adult females that had fed on pear leaves and the low hatch rate of the eggs produced by those females.     

Population dynamics of the citrus red mite, Panonychus citri (McGregor) (Acari: Tetranychidae) in Japanese pear orchards

In spring a population of the citrus red mite (Panonychus citri),a non-diapausing species, migrated to a Japanese pear orchard, mainly from nearby Japanese holly trees, but in autumn most of the mites starved to death while the rest returned to the holly trees. In the Japanese holly trees, the population of mites reached their maximum density in late May1993 and in mid-June 1994 on overwintered leaves and moved to newly opened leaves in mid-June 1993 and late June 1994. The mites tended to disperse abruptly in early June or mid-June and again towards the end of June. The mites inhabiting the holly trees appeared to migrate to the Japanese pear trees in June but their densities on pear leaves remained low until mid-August. In the pear orchard, the mites initially tended to increase on pear leaves near the holly trees and then gradually spread to other leaves farther away from the holly trees. Their highest density in the pear orchard occurred in mid-October. When pear leaves were inoculated with two or five female adults at different times from May to September, the leaves inoculated before mid-August showed no increase in the number of mites. A possible cause for the suppression of the population increase on pear leaves from June to mid-August is discussed. This revised version was published online in November 2006 with corrections to the Cover Date.     

柑桔全爪螨（蜱螨亚纲：叶螨科）在梨树上季节性发生影响种群动态

柑桔全爪螨为害梨树时春夏种群密度极低但随后却突然爆发,形成一年之中只有秋季一个高峰期之发生规律,这与其在柑桔上一年之中两个发生高峰期的发生特点形成鲜明对照。为阐明柑桔全爪螨在梨树直的这种季节消长规律之成因,本采用对比研究方法分析研究了该螨在梨叶和柑桔叶一年之中的产卵率,成活率以及卵的孵化率等生态学习性。结果表明产卵率在梨叶与柑桔叶之间全年均无显差异;然而其在梨叶上的成活率以及卵的孵化率在八月之产明显低于其在柑桔叶上之值,且差异显或极显,但八月之后以上各项指标在梨叶和柑桔叶上均无显差异。     

食螨瓢虫自然种群基地建立的研究

腹管食螨瓢虫Stethorus siphonulus Kapur是福建省柑桔全爪蠕(红蜘蛛)Panonychus eitri MeGregor的优势种天敌,控制作用显．已在我省柑桔产区大面积应用成功。为了使柑桔全爪蠕生物防治持续发展,古螨瓢虫自然种群基地的建立至关重要．本将多年来在闽清白中柑桔场、福建农业大学金山柑桔园、福州北郊峙头柑桔场、长泰柑桔园等地进行食螨瓢虫自然种群基地建立的研究,进行总结报道。     

桔全爪螨与柑桔相互作用的研究

研究了不同柑桔品种对桔全爪螨Ｐａｎｏｎｙｃｈｕｓｃｉｔｒｉ（ＭｃＧ）种群的影响,桔全爪螨危害对柑桔生理的影响以及柑桔叶片受受后对桔全爪螨种群的反馈作用,结果表明：供试的１０个柑桔品种对桔全爪螨种群生长发育,繁殖时明显的影响,品种间存在感螨性差异。     

Stage-specific population dynamics of cottony cushion scale,Icerya purchasi (Hemiptera: Monophlebidae), in citrus orchards in Jeju,Korea

The cottony cushion scale, Icerya purchasi Maskell (Hemiptera: Monophlebidae), is a polyphagous, cosmopolitan and destructive pest of citrus. This study was conducted to obtain the stage-specific phenology of I. purchasi for seasonal management strategies in the field. Movement of crawlers (hatched nymphs) in egg sacs of overwintered females started in late May, peaked in early to mid-June, and was completed by late June. Generally, the 1st generation occurred from late May until late September and the overlapping second generation occurred from early September. The 1st nymphs in the 1st generation peaked in mid June. The 2nd nymphs showed peak activity in late July. The 3rd nymphs showed peak population in early September. The 1st generation adults peaked in mid September. In the 2nd generation, the 1st nymphs peaked in early October, the 2nd nymphs showed peak activity in late October, and the 3rd nymphs reached a plateau after mid October. The 2nd generation adults occurred from late October. Consequently, two life cycles were competed in the Jeju area. The average fertilities of I. purchasi were 623 and 247 crawlers per female in overwintered and summer generations, respectively. An average of 20.7% of all citrus orchards was infested with I. purchasi, with a mean of 3.9% infested trees in Jeju. These results should be useful in establishing management strategies for I. purchasi in citrus orchards.