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1.
为了准确掌握梨小食心虫的产卵特性,研究模拟室外条件下该虫在不同寄主果树的叶片、桃枝不同部位及不同品种桃果上的产卵偏好.结果表明: 梨小食心虫成虫对7种寄主果树叶片的产卵偏好由高至低依次为:桃>樱桃>苹果>李>梨>海棠>杏.在桃树叶片上的产卵量占总产卵量的33.5%,平均单叶卵量达8.3粒;虫卵在不同寄主叶片正、反两面的分布有所差异,苹果和海棠叶片正面卵量多于背面,桃、李、梨、杏叶背面卵量多于正面,桃叶背面卵量是正面的3.3倍,樱桃叶两面卵量差异不明显;该虫在桃枝上产卵部位选择顺序为:叶片>托叶>叶柄>枝条,叶片是其主要产卵部位,占总产卵量的88.7%;梨小食心虫在桃枝上主要选择靠近顶端未展叶的前10片桃叶背面产卵,前10叶卵量占总产卵量的725%,其中第3片叶上产卵最多,占9.3%;第25叶以后仅占总产卵量的1.1%;在不同类型桃果上的产卵偏好次序为:油桃>蟠桃>毛桃;绒毛疏密及其特点是影响梨小食心虫在寄主果树叶片和果实上产卵选择的首要因素.  相似文献   

2.
苹果蠹蛾成虫产卵特性   总被引:1,自引:1,他引:0  
苹果蠹蛾Cydia pomonella(L.)是全球温带地区果园主要害虫之一,是中国的重要检疫性有害生物,对我国苹果、梨等水果的安全生产造成极大危害及威胁。为详细了解苹果蠹蛾的产卵特性,从而为进行有效的监测与防控提供基础信息,作者于2006年在甘肃省山丹县梨果园中对树冠不同高度与朝向的蛀果率进行了调查,并于2010在内蒙古阿拉善左旗对梨树果枝上不同部位的产卵量进行了详细调查。主要研究结果如下:1)树冠2.5m以上的蛀果率显著高于2.5m以下的蛀果率,树冠东面的蛀果率最高,南面的蛀果率最低;2)在整个果园中,靠近北侧的果树上果实受害程度要高于南侧果树上的果实受害程度,整个果园中蛀果率由北向南逐渐降低;3)叶片上的卵数最多,占总卵数的73.1%,果实上的卵数次之,占总卵数的14.6%,枝条上的卵数最少,占总卵数的12.2%;4)在产卵的叶片上,卵主要产在叶背面,叶片背面卵量是叶正面的6.65倍。鉴于以上研究结果,在开展化学防治或颗粒体病毒防治时,应注意充分喷施果树上层树冠,且在对果实进行处理的同时,叶片和枝条也需要充分喷药。  相似文献   

3.
棉铃虫卵在不同生育期玉米上的分布   总被引:2,自引:0,他引:2  
1998年在江苏丰县系统调查了棉铃虫卵在不同生育期玉米上的垂直分布和水平分布。表明棉铃虫在抽雄扬花期以前的玉米上产卵 ,2代期间叶片正面占总卵量的 93 5% ,茎杆上占 6 5% ,3代期间叶片正面占 89 5% ,茎杆上占 1 0 5% ;抽雄扬花期主要产在雄穗和新鲜的雌蕊花丝上 ,分别占 59 1 %和2 6 9% ,叶片正面和茎杆上分别只占 1 1 1 %和 2 9%。抽雄扬花后有 97 5%的卵产在雌蕊花丝上 ,叶片和茎杆上为 0 5%和 2 0 %。第 3代棉铃虫卵期 ,抽雄扬花期的玉米对卵的分流作用约为抽雄扬花前玉米的 3倍 ,抽雄扬花后的玉米对卵的分流作用最小。  相似文献   

4.
银杏大蚕蛾卵空间分布与环境关系的研究   总被引:3,自引:0,他引:3  
银杏大蚕蛾DictyoplocajaponicaMoore在重庆市城口县 1年发生 1代 ,以卵越冬。卵分布与树龄、树干的关系为 :卵主要分布于 2 0~ 30年盛果期的核桃果树上 ,2 0年生以下及 30年以上的果树则分布较少 ;树干 1m以下的粗皮裂缝内分布的卵占总卵量的 72 5 % ;卵在林间的分布呈低密度、高聚集块状 ,为该虫的预测预报和生产防治提供科学依据。  相似文献   

5.
【目的】明确新疆新发外来入侵生物番茄潜叶蛾幼虫和卵在不同种群密度下的垂直分布、空间分布型和理论抽样数,探索田间易观察的危害症状和幼虫密度的关系,为田间取样和调查提供理论指导。【方法】在察布查尔县连续调查3个大棚同一品种京番502杂交一代上的番茄潜叶蛾的不同种群密度,利用聚集度指标及Iwao回归分析,计算并分析了番茄潜叶蛾卵和幼虫在不同种群密度下的空间分布型、垂直分布和理论抽样数,分析危害叶片数、虫道长度和虫道数与幼虫密度的动态关系。【结果】计算并统计番茄潜叶蛾幼虫和卵的空间分布聚集度指标的均值m、扩散系数C、扩散型指数I、负二项分布值K、平均拥挤度m~*、聚块指数m~*/m、扩散指数CA和种群聚集均数λ。番茄潜叶蛾卵主要集中在上部,占比43.9%~100%。幼虫主要集中在下部,占比53.3%~100%。番茄潜叶蛾幼虫数与虫道数、虫道长度或为害叶片数的比值随为害加剧呈动态变化。番茄潜叶蛾幼虫和卵Iwao直线回归方程拟合公式为m~*=1.9114+1.2055m (R~2=0.9703)和m~*=0.0536+1.4147m (R~2=0.9014)。根据空间分布型参数,在D=0.1、0. 2和0. 3时,幼虫的理论抽样数模型分别为n=1118. 4/x+78. 9、n=279. 6/x+19.7、n=124.3/x+8.8,卵的理论抽样数模型分别为n=404.8/x+159.3、n=101.2/x+39.8、n=45.0/x+17.7,该模型适用于不同虫口密度下的田间抽样。【结论】在京番502杂交一代上,番茄潜叶蛾幼虫为m=0.6头·株~(-1)以上,卵在达到密度最大值前,均呈聚集性分布。番茄潜叶蛾成虫偏好在幼嫩的叶片产卵,随植株被害加剧该偏好略有减弱。当番茄潜叶蛾幼虫的虫口密度为10和30头·株~(-1)时,建议分别取样50和30株;当卵量为10和30粒·株~(-1)时,分别取样50和45株。  相似文献   

6.
香蕉假茎象甲卵的空间格局研究   总被引:3,自引:0,他引:3  
陆永跃  梁广文  曾玲 《昆虫知识》2002,39(3):203-205
应用多种聚集度指标研究了香蕉假茎象甲卵在香蕉园的空间分布格局 ,结果表明该虫卵在所有密度下都是聚集分布 ,聚集程度与密度不相关 ,分布的基本成份是个体群。在空间格局研究基础上提出了理论抽样数公式 ,给出了不同密度下、不同误差要求的最适抽样数。  相似文献   

7.
柳厚壁叶蜂幼虫空间格局及抽样技术   总被引:3,自引:0,他引:3  
应用Taylor的幂法则、Iwao m*-m回归分析法及6个聚集指标,对柳厚壁叶蜂幼虫空间分布型进行了研究,并进行了影响因素分析.结果表明,该幼虫在柳树的枝条和叶片两个空间阶元都属于聚集分布,分布的基本成分是个体群,其聚集性随密度的增大而增加.在枝条上,聚集的原因是由柳厚壁叶蜂成虫集中产卵的习性与枝条上叶片空间位点共同影响所致;在叶片上,当m<2.37时,其聚集原因与春季柳树新叶空间位置有关,当m>2.37时,虫瘿聚集除与春季新叶空间位置有关外,还与柳厚壁叶蜂成虫羽化和在叶片上集中产卵的习性有关.运用Iwao m*-m回归中的两个参数α和β值,确定了在不同精度下的理论抽样数及序贯抽样数.  相似文献   

8.
烟粉虱成虫空间分布型的研究   总被引:13,自引:0,他引:13  
对烟粉虱Bemisiatabaci成虫在单株茄子(SolanummelongenaL.)、西瓜(CitrullusvulgarisSchard)和甜瓜(CucumismeloL.)上的分布规律及其空间分布型进行了研究。在植株上中部较幼嫩且已充分展开之叶片上烟粉虱成虫数量最多,成虫呈聚集分布。成虫在黄瓜(CucumissativusL.)上亦呈聚集分布,确定了不同虫口密度情况下的最适抽样数。  相似文献   

9.
杨扇舟蛾卵和幼虫的空间分布型及抽样技术   总被引:6,自引:1,他引:5  
研究了杨扇舟蛾Clostera anachoreta(Fabricius)卵和幼虫的空间分布型及抽样技术,结果表明杨扇舟蛾卵和幼虫在杨树林的分布型均为聚集型中的负二项分布。几种抽样方法中,卵以棋盘式最好,幼虫以平行线法最好。同时建立了杨扇舟蛾卵的下层抽样模型为y=2.4481x 0.4243;幼虫的中、下层抽样模型为y=2.4605x 3.9126。  相似文献   

10.
稻苞虫卵空间格局参数特征及其应用   总被引:3,自引:0,他引:3       下载免费PDF全文
近年来,稻苞虫已成为川西北稻区仅次子螟虫的严重害虫.为对其生物学特性的进一步了解,1978—1983年对猖獗世代(第三代)卵在稻田空间格局进行了研究,结果表明稻苞虫卵在稻田呈负二项分布;格局的结构是以疏松的个体群形式存在;个体群间是聚集的,个体群内的卵粒是随机的.利用空间格局参数Mk、α、β值,估计了个体群的大小和与平均密度的关系;分析了卵在稻田聚集的原因;探讨了平均卵密度与k值的关系.依:(x-)=K(P-1/k0-1)关系由未着卵频率(P0)来估计卵密度.给出了以零频率估计卵密度和以概率保证的理论抽样数方法的结合,来实现有效的简易抽样.同时以未着卵丛率来检定田间发生程度和以卵量来检定是否达到现行防治阈限的序贯抽样检索.  相似文献   

11.
A number of studies have focused on the selection and use of new biocontrol agents, but the effects of the introduction of these microorganisms on non-target organisms, including the crop plants themselves, are not well known. Non-target effects of sprayed applications of a potential biocontrol agent of apple powdery mildew (Podosphaera leucotricha Ell. Et Ev.), on scab infections (Venturia inaequalis Cooke Winter), on codling moth [Cydia pomonella L. (Lepidoptera: Tortricidae)] oviposition and damage and apple (Malus x domestica) fruit quality are examined. This biocontrol agent, an epiphytic yeast isolate called Y16, affected neither conidia germination of V. inaequalis nor their penetration of the leaf tissue but suppressed the disease caused by this pathogen. The quantity of eggs laid by the codling moth during its second flight period on yeast treated trees was significantly different to the quantity of eggs laid on the untreated trees. In the first season of the experiments, more eggs were laid on the treated trees, especially on those tree parts closest to the fruit. These results, however, were not confirmed the following season: fewer eggs were laid on the treated trees than on the untreated trees. These conflicting observations are attributed to year-to-year variation in environmental conditions, which may affect yeast survival and activity. A 2-month-long assay was conducted in the orchard during the codling moth's second flight period from mid-July until mid-September. The yeast treatment did not affect the damage caused by the codling moth to the fruits. Finally, the yeast treatment did not affect any of the examined fruit quality parameters.  相似文献   

12.
Studies were conducted in 1997 and 1998 to evaluate the effects of three particle film formulations consisting of kaolin and adjuvants on neonate larvae, ovipositing adult females, and eggs of the codling moth, Cydia pomonella (L.). Neonate larval walking speed, fruit discovery rate, and fruit penetration rate on apple host plants coated with particle films were significantly lower than on host plants without particle films in laboratory assays. Females oviposited less on host plants covered with a particle film residue than on untreated plants in laboratory choice and no-choice tests. Hatch rate of codling moth neonate larvae was unaffected by particle films sprayed on host plants either before or after oviposition. Fruit infestation rates were significantly reduced on particle film-treated trees compared with untreated trees for both first- and second-generation codling moth in field trials in both apple and pear orchards. Particle films appear to be a promising supplemental control approach for codling moth in orchards where moth density is high, and may represent a stand-alone method where moth densities are lower.  相似文献   

13.
Codling moths, Cydia pomonella L. (Lepidoptera, Tortricidae), of the first generation deposit eggs on apple leaves in the vicinity of small fruits. The choice of the suitable oviposition sites and proper fixation of eggs are expected to be crucial factors for the survival of the offspring. In this study, we investigated egg adhesion of the codling moth to leaf surfaces of different cultivars of the domestic apple, Malus domestica Borkh., by measuring the pull-off force required to detach the eggs from leaves. Since surface features may influence insect egg adhesion, morphological and physicochemical properties (wettability, free surface energy) of these leaf surfaces were analyzed. Furthermore, eggs and their adhesives covering leaf surfaces were visualized. Eggs on the smooth upper leaf surfaces of all tested cultivars required significantly similar pull-off forces to be detached, at a total average of 6.0?mN. Up to 2?C3 times stronger pull-off forces had to be applied to detach eggs from trichome-covered lower leaves, and these forces differed significantly between cultivars. The role of leaf surface properties is discussed in the context of egg adhesion, oviposition site choice, female attachment, as well as neonate locomotion speed and survival. The obtained results shed light on the susceptibility of various apple cultivars and leaf surfaces to the infestation of apple trees by first-generation codling moths.  相似文献   

14.
Based on the premise that augmented host numbers may help multiply and support parasitoid populations, the egg parasitoid Trichogramma platneri Nargarkatti was released in apple orchards which were participating in a sterile codling moth, Cydia pomonella (L.), release program. Nonviable eggs resulting from matings involving at least one sterile codling moth partner can be successfully parasitized by T. platneri. Grain moth-reared, as well as codling moth-reared, T. platneri were released either in the spring or in the spring and summer oviposition period(s) of wild codling moth. Sentinel codling moth eggs were hung weekly, for 3-day periods, from May until September to determine fluctuations in T. platneri populations both during and between releases. Low numbers of wild or nonviable codling moth eggs or other susceptible host eggs resulted in sufficient eggs to maintain low spring- or summer-introduced T. platneri populations. T. platneri reduced codling moth damage in trees in which the Trichogramma were released.  相似文献   

15.
Codling moth, Cydia pomonella Linnaeus (Lepidoptera: Tortricidae), is a serious pest of apples worldwide. This study aimed to evaluate the mortality rate of codling moth eggs, larvae and pupae in the field in commercial and neglected apple and walnut orchards over two years, and to investigate the biodiversity and intensity of parasitoids associated with codling moth in the orchards. Five patches of wax paper containing 1-day-old codling moth eggs were placed in a neglected orchard in order to evaluate parasitism rates. Corrugated cardboard bands were placed around the trunk of 15 trees during late spring and the beginning of summer through to fruiting season to capture and measure parasitism of codling moth larvae. 5285 larvae in total were collected during this study. Mortality rate (egg?+?larvae?+?pupae) varied between the commercial and neglected orchards, reaching a maximum of (42.89% and 66.67%) in neglected apple orchards and (61.03% and 74.76%) in the neglected walnut orchard in 2003 and 2004, respectively. Trichogramma cacoeciae (Hymenoptera: Tichogrammatidae) was the only egg parasitoid recorded. Eight hymenopteran larval and pupal parasitoids belonging to several subfamilies were recorded: Cheloninae, Agathidinae, Cremastinae, Haltichellinae, Chalcidinae, Anomalinae, and Pteromalinae and one dipteran belonging to Tachininae. In conclusion, mortality factors, mainly by parasitoids, are contributing to a general reduction in codling moth larvae populations particularly in neglected orchards. The hymenopteran Ascogaster quadridentata and the dipteran Neoplectops pomonellae can contribute to biological control programmes against codling moth in the coastal region and other regions.  相似文献   

16.
Insecticide bioassays were used to investigate resistance of Cydia pomonella (L.) (Lepidoptera: Tortricidae) to insecticides with various types of active ingredients. The efficacy baselines of selected insect growth regulators (fenoxycarb), insect growth inhibitors (diflubenzuron and teflubenzuron), organophoshorous insecticides (phosalone), and neonicotinoids (thiacloprid) against the eggs and first and fifth instars of sensitive laboratory strains of codling moth were determined. According to concentration-mortality baseline, 50% lethality concentration values and 90% lethality concentration values were determined for all the tested insecticides. The lethal concentration ratio quantified the relation between the efficacy of selected insecticides against fifth instars found by topical application and against first instars found by diet-treated bioassay. No difference was detected when the efficacy of technical grade diflubenzuron diluted in tetrahydrofuran and diflubenzuron in the formulated product Dimilin 48 SC diluted in water was compared. However, just before the application of insecticide, the integument of larvae must be treated with acetone. Two bioassays were used to monitor the resistance of codling moths collected in 2003-2005 in two apple (Malus spp.) orchards with different intensities of chemical control. Resistance ratios (RRs) to the tested insecticides were determined for both field populations of codling moth. For the population of codling moth from a commercial apple orchard in Velké Bílovice, cross-resistance to fenoxycarb, teflubenzuron, and phosalone was detected after the topical application of insecticides to fifth instars. The population of codling moth from Prague-Ruzyne was slightly resistant to phosalone and teflubenzuron. No resistance to diflubenzuron was detected in either tested population.  相似文献   

17.
The phenology of oriental fruit moth, Grapholita molesta (Busck), on apple (Malus spp.) in North Carolina was studied using pheromone traps and egg sampling in abandoned and commercial orchards in 2000 and 2001, with subsequent development of an oviposition degree-day model and management studies in relation to codling moth, Cydia pomonella (L.), phenology. Oriental fruit moth eggs were found in greater numbers on leaves early and on fruit later in the growing season, on the top versus the bottom of the leaf surface, and on the calyx area versus the side or stem end of the fruit. A degree-day (DD) model to predict oriental fruit moth oviposition was developed based on temperature accumulations from peak moth trap capture of the first (overwintering) generation, by using 7.2 and 32.2 degrees C as the temperature limits. The model predicted four ovipositing generations of oriental fruit moth with the second beginning 507 DD after peak moth catch. Using predictions of the oriental fruit moth and codling moth degree-day oviposition models, an experiment was conducted to determine the level of second generation oriental fruit moth control with methoxyfenozide applied under different scenarios for first generation codling moth. Methoxyfenozide was equally effective in managing codling moth and oriental fruit moth for all treatment timings.  相似文献   

18.
A series of studies were conducted to examine the residual activity and toxicity of the ecdysone agonists tebufenozide and methoxyfenozide to codling moth, Cydia pomonella (L.), and oriental fruit moth, Grapholita molesta (Busck), in North Carolina apple systems. Methoxyfenozide exhibited greater activity than tebufenozide against codling moth eggs in dose-response bioassays, with a 4.5- and 5.3-fold lower LC50 value to eggs laid on fruit treated before or after oviposition, respectively. Oriental fruit moth eggs were 57- and 12-fold less sensitive to methoxyfenozide than were codling moth eggs on fruit treated before and after oviposition, respectively. Methoxyfenozide was effective in reducing larval entries of both codling moth and oriental fruit moth in field residual activity bioassays, exhibiting activity for at least 28 d after application. Residue breakdown on fruit was approximately 80% at 28 d after treatment for both methoxyfenozide and tebufenozide, with the most rapid residue decline (60%) occurring during the first 14 d after application. Two applications of methoxyfenozide applied at 14-d intervals provided better canopy coverage and higher residue levels than one application. Spray volume (683 versus 2,057 liters/ha) did not affect the efficacy of methoxyfenozide. Leaf and fruit expansion during the season was measured to determine potential plant-growth dilution effects on residual activity. There was very little increase in leaf area after mid May, but increase in fruit surface area over the season was described by a second order polynomial regression. Implications for codling moth and oriental fruit moth management programs are discussed.  相似文献   

19.
The codling moth, Cydia pomonella (L.), and oriental fruit moth, Grapholita molesta (Busck), are two key pests of apple (Malus domestica Borkh.) in North Carolina. Growers extensively relied on organophosphate insecticides, primarily azinphosmethyl, for > 40 yr to manage these pests. Because of organophosphate resistance development and regulatory actions, growers are transitioning to management programs that use new, reduced-risk, and OP-replacement insecticides. This study evaluated the toxicity of a diversity of replacement insecticides to eggs, larvae, and adults, as well as an assessment of their residual activity, to codling moth and oriental fruit moth. Laboratory-susceptible strains of both species were used for all bioassays. Fresh field-harvested apples were used as a media for assessing the ovicidal activity of insecticides. For larval studies, insecticides were topically applied to the surface of lima bean-based diet, onto which neonates were placed. Toxicity was based on two measures of mortality; 5-d mortality and development to adult stage. Ovicidal bioassays showed that oriental fruit moth eggs were generally more tolerant than codling moth eggs to insecticides, with novaluron, acetamiprid, and azinphoshmethyl having the highest levels of toxicity to eggs of both species. In contrast, codling moth larvae generally were more tolerant than oriental fruit moth to most insecticides. Methoxyfenozide and pyriproxyfen were the only insecticides with lower LC50 values against codling moth than oriental fruit moth neonates. Moreover, a number of insecticides, particularly the IGRs methoxyfenozide and novaluron, the anthranilic diamide chlorantriliprole, and the spinosyn spinetoram, provided equal or longer residual activity against codling moth compared with azinphosmethyl in field studies. Results are discussed in relation to their use in devising field use patterns of insecticides and for insecticide resistance monitoring programs.  相似文献   

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