马尾松毛虫空间格局的地学统计学分析

应用地学统计学方法分析了湿地松 马尾松 火炬松林中马尾松毛虫越冬代蛹、第一代卵块和低龄幼虫的空间格局 .结果表明 ,蛹在 0°、45°、90°、1 35°4个方向上的半变异函数曲线为球形 ,在 90°方向上的空间连续性大于其他方向 ;卵块和低龄幼虫的为指数形 ,在各方向上无差异 .蛹、卵块和幼虫在全方向上的半变异函数曲线均为球形 ,呈聚集型的空间格局 ,聚集强度以蛹最高 ,依次是幼虫和卵块 .分别拟合了蛹、卵块和幼虫的半变异函数模型 ,估算了样地各处的密度 ,绘制了密度等值线图     

城市污泥堆肥温度的空间变异性研究

利用半变异函数对城市污泥堆肥温度的空间变异特性进行了研究 ,对堆体温度进行了克里格法 ( KRIGING)插值。采用通风静态垛堆肥工艺 ,试验了 0 .79、2 .0 3m3 / ( min·m3 )两种通风量。沿着堆肥池长度方向设定 2个纵剖面 ,每个纵剖面的面积为 6 .0 m× 1 .0 m,按 0 .5 m× 0 .1 m布设网格。结果表明 ,在水平方向上堆肥温度的半变异函数用球状模型进行拟合效果较好 ,而在垂直方向上的半变异函数用线性模型进行拟合效果较好 ;在水平方向上两个剖面的温度变程 ( range)分别为 0 .90 m、1 .2 5 m,在垂直方向上的变程分别为 0 .75 m、1 .0 0 m;利用克里格法进行最优内插估值得到的温度等值线图表明 ,高温区域一般位于堆体中层 0 .4～ 0 .6 m,低温区域一般位于堆体下层 0～ 0 .4 m;从温度剖面等值线图判断 ,中试规模的城市污泥堆肥 ,其合理通风量小于 0 .79m3 / min· m3 。     

不同土地利用方式下沙地土壤水分空间变异规律

利用地统计学的方法 ,研究了科尔沁沙地甸子地不同土地利用方式草地和玉米地春季土壤含水量的空间变异规律。结果表明 ,草地表层、亚表层土壤含水量的变异函数均可很好地拟合成球状模型 ,具有明显的空间结构特征 ,其空间相关度分别为 0 979、0 999,变程分别为11 5 7m、19 4 1m ,分数维分别为 1 5 71、1 5 35 ,Moran’sI系数表现为在近距离内 (0 5～ 2 5m)为较强的正相关 (I=0 3～ 0 8) ,随着距离的增大 ,相关性变小 ,>5m后表现为较弱的负相关(I =0 2 )的变化趋势 ,克立格制图均表现出中央和四周高 ,西北角存在明显过渡带的空间分布格局 ,表层和亚表层具有很大的相似性。而耕地表层、亚表层土壤含水量变异函数分别拟合成线性和球状模型 ,其空间相关度分别为 0 344、0 914 ,变程分别为 7 6 7m、9 31m ,分数维分别为 1 92 8、1 6 81,Moran’sI系数分析和克立格制图表明表层、亚表层土壤含水量存在明显的差异。因此草地和耕地土壤含水量变异函数模型及参数、分数维、Moran’sI系数和克立格制图均存在明显的区别。同草地相比 ,玉米地土壤含水量空间格局特征表现为空间依赖性小 ,随机性大 ,空间自相关作用范围小 ,破碎化程度高。所以有必要采取退耕还草的措施来保护和恢复沙地生态系统的健康。     

栎黄枯叶蛾低龄幼虫空间分布的地统计学分析

栎黄枯叶蛾(Trabala vishnou gigantina Yang)是近年在陕西吴起发现的严重危害沙棘的一种食叶害虫。为了准确把握栎黄枯叶蛾幼虫的分布规律,以便对该虫的危害盛期进行预测预报和采取防治措施,因而采用地统计学分析方法对不同坡向和疏密度的沙棘林中栎黄枯叶蛾低龄幼虫的空间分布格局进行了研究。结果表明:栎黄枯叶蛾卵孵化高峰期为6月中旬。通过全方向的变异函数曲线分析得知:阴坡密林、阴坡疏林、阳坡密林、阳坡疏林中,栎黄枯叶蛾低龄幼虫空间依赖范围分别为19.96、9.45、20.75、13.48 m,空间变异值分别为0.692、0.613、0.679、0.597。密林样地的半变异函数最佳拟合模型均为高斯模型,疏林样地均为指数模型,两种模型均指明栎黄枯叶蛾低龄幼虫的空间分布格局为聚集分布。引起种群聚集的原因主要为其生物学特性。用Kriging插值方法生成的空间分布图显示低龄幼虫在空间分布上存在明显的边缘效应。     

长白山岳桦种群格局的地统计学分析

应用地统计学的原理和方法研究了长白山岳桦种群空间分布格局及其空间相关关系,首先通过样方调查数据计算岳桦材积的半变异函数,拟合半变异函数模型,然后根据拟合的最优半变异函数模型,进行空间数据插值、绘制岳桦材积的克立拉图,最后对所得到的不同海拔质海拔岳桦材积的半变异函数图和克立格图进行分析。结果表明,在海拔1650－1700m岳桦材积的半变异函数曲线为球形,其空间分布格局为聚集型,种群呈衰退趋势;海拔1750－2000m岳桦材积的半变异函数曲线为直线形,其空间分布格局为随机型,种群较稳定;在海拔2000－2150m岳桦材积的半变异函数曲线为球形,其空间分布格局为聚集型,种群呈增长趋势,这说明长白山桦整体上有一种向上迁移的趋势,尤其是过渡带中的岳桦表现则为更为明显。     

桃园生草复合生态系统中桃蚜与草间小黑蛛种群的地统计学分析

利用地统计学原理和地理信息系统(GIS)分析了桃园生草模式下不同时期桃蚜Myzus persicae(Sulzer)种群和草间小黑蛛Erigonidium graminicola Sundevall种群的空间分布格局和空间相关性。结果表明,不同时期桃蚜和草间小黑蛛种群均存在较强的空间相关性,其理想的半变异函数曲线为高斯、圆型、指数或球型,其空间格局均呈聚集分布,变程范围分别为6.8630¹2.0903 m、6.863012.0903 m、6.8630¹2.6980 m,空间结构比例分别为0.011312.6980 m,空间结构比例分别为0.0113⁰.6546、0.06760.6546、0.0676⁰.6129,表明桃园生草模式下桃树草间小黑蛛对桃蚜在空间位置上具有追随关系,对其种群数量的控制有较大作用,草间小黑蛛是桃蚜的优势天敌。     

田块尺度下土壤磷素的空间变异性

采用经典统计学与地统计学相结合的方法,对中国科学院沈阳生态实验站30 m×42 m样地进行网格法分层(0～10和10～20 cm)取样,研究了田块尺度下土壤全P和Olsen-P的空间变异特征.结果表明,49对样本土壤Olsen-P的变异系数(4.5%～5.42%)远高于全P(11.8%～13.33%);全P和Olsen-P具有较好的空间结构且具有较相近的空间相关距离.最佳理论模型的参数显示各变量空间变异主要受结构性因素的影响,各变量半方差变异函数的C/(C₀+C)均高于%.全P和Olsen-P之间及在2个土层之间均具有较相似的空间分布格局.变异系数结合空间格局分析可以大大降低试验取样的数量.     

朝鲜球坚蚧及黑缘红瓢虫空间格局的地统计学研究

利用地统计学方法研究了不同时期朝鲜球坚蚧(Didesmococcus Koreanus Borchs)若虫及黑缘红瓢虫（Chilocorus rulidus Hope）幼虫种群的空间分布格局和空间相关性。结果表明,不同时期朝鲜球坚蚧若虫种九和黑缘红瓢虫幼虫种群的半变异函数均可拟合为球型,其空间格局为聚集型,在小尺度上,空间变异主要是由其空间自相关引起的,且不同时期格局变化不明显,变程分别为9.56-15.70m和18.83-19.74m之间。黑缘红瓢虫种群与朝鲜球坚蚧种群之间具有很强的追随关系,说明黑缘红瓢虫种群是朝鲜球坚蚧种群的优势天敌。     

麦红吸浆虫及其卵寄生蜂混合种群空间格局

运用地统计学方法对不同时期麦红吸浆虫及其卵寄生蜂混合种群(宽腹姬小蜂和尖腹黑蜂)的空间格局进行了分析.结果表明:麦红吸浆虫休眠体的半变异函数的最优模型为球型,成虫的最优模型为球型-指数型,幼虫最优模型为线性有基台型,卵寄生蜂混合种群半变异函数的最优模型为球型-指数型.麦红吸浆虫休眠体、成虫羽化初期、成虫羽化高峰期、幼虫和卵寄生蜂混合种群的空间相关范围分别为53.6、190.6、154.1、4.2和280.3 m,空间变异强度分别为30.5%、95.6%、96.3%、14.9%和95.3%.采用普通克立格插值法模拟的空间分布模拟图可较好地从时间、空间两个角度直观地分析不同时期麦红吸浆虫及其卵寄生蜂混合种群的动态变化.     

有机磷类杀虫剂对美洲斑潜蝇的防治效果

在山东青州以西葫芦为试验害虫寄主 ,测定了毒死蜱、三唑磷、乙酰甲胺磷、辛硫磷、马拉硫磷对美洲斑潜蝇幼虫LiriomyzasativaeBlanchard的田间防效。毒死蜱 (2 4g (a .i.) 667m2 )、三唑磷 (1 0g (a.i.) 667m2 )、乙酰甲胺磷 (2 0g (a .i.) 667m2 )第 3～ 7d校正防效为 97 0 9%～ 97 1 4% ,86 80 %～87 0 4% ,85 99%～ 86 2 5 %。此 6个处理药效顺序为毒死蜱 >三唑磷 >乙酰甲胺磷 (2 0g(a.i.) 667m2 )>乙酰甲胺磷 (1 5g(a.i.) 667m2 ) >辛硫磷 >马拉硫磷。在河南洛阳以甘蓝为试验害虫寄主 ,乙酰甲胺磷 (1 5g(a.i.) 667m2 )、敌敌畏 (2 5g(a.i.) 667m2 )、敌百虫 (4 5g(a .i.) 667m2 )对美洲斑潜蝇幼虫第 7d校正防效分别为 76 98% ,82 42 % ,71 1 1 %。毒死蜱对在不同寄主上美洲斑潜蝇的防效均较好     

Effects of cultivar on oviposition preference, larval feeding and development time of diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), on some Brassica oleracea vegetables in Victoria

Abstract We studied oviposition preference of Plutella xylostella for four cultivars of cabbage, broccoli and cauliflower in the field. There were no differences in the number of eggs found on the various cultivars of broccoli or cauliflower. Significantly more eggs were laid on cultivar Savoy King than any of the other cabbage cultivars tested. We then compared the development time and feeding damage of larvae reared on Savoy King and Green Coronet cabbages. Larvae developed more rapidly and fed more and for longer on Green Coronet than Savoy King. Thus, while Savoy King is more attractive to oviposition in the field, net impacts on the crop may be lessened to some degree through lower feeding proficiency of the larvae on that cultivar.     

Using yellow rocket as a trap crop for diamondback moth (Lepidoptera: Plutellidae)

Yellow rocket, Barbarea vulgaris (R. Br.) variety arcuata, was evaluated as a trap crop for diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), in cabbage, Brassica oleracea L. variety capitata, in 2003 and 2004. In 2003, the numbers of P. xylostella larvae found in field plots of cabbage alone were 5.2-11.3 times higher than those on cabbage plants in plots that included cabbage and several rows of yellow rocket. In an outdoor experiment in screenhouses, P. xylostella oviposition on cabbage was compared among six treatments that varied in the percentage of yellow rocket in relation to cabbage (0, 4, 8, 16, 24, and 32% of the plants were yellow rocket). Results indicated that the percentage of eggs laid on cabbage decreased as the percentage of yellow rocket in the treatment increased, but this decrease was not significant beyond 20% of the plants being yellow rocket. In 2004, the numbers of P. xylostella larvae in field plots of cabbage alone were 1.6-2.4 and 1.7-2.8 times higher than numbers in treatments with 10 and 20% trap crop, respectively. Sticky trap and sweep net captures of P. xylostella adults indicated that within-field dispersal was reduced by the presence of yellow rocket and aggregation occurred around yellow rocket plants. Our study suggests that using yellow rocket as a trap crop may reduce P. xylostella infestations in cabbage fields, and this possibility is discussed in the context of general crop and insect pest management practices in crucifers.     

取食不同食物对小菜蛾幼虫肠道细菌多样性的影响

【目的】植食性昆虫肠道细菌的组成与其食物密切相关。本研究旨在探究小菜蛾Plutella xylostella幼虫肠道细菌多样性与其取食食物之间的关系以及它们之间相互适应的过程。【方法】本研究选取小菜蛾人工饲料品系(S)及其转寄主到结球甘蓝Brassica oleracea var. capitata、结球白菜Brassica rapa subsp. pekinensis和花椰菜Brassica olerocea var. botrytis饲养后第1代(分别为G1C, G1CC和G1WC)和第3代(分别为G3C, G3CC和G3WC)的4龄幼虫,提取小菜蛾肠道细菌基因组DNA,利用Illumina MiSeq二代高通量测序技术,分析其肠道细菌多样性和丰度。【结果】α多样性指数分析发现,取食不同食物的小菜蛾4龄幼虫肠道细菌多样性高低顺序为G1WC>G1CC>S>G1C。在菌群组成上,以人工饲料为食的S样品肠道细菌主要由厚壁菌门(Firmicutes)组成,转寄主植物后的G1C, G1CC和G1WC肠道中厚壁菌门(Firmicutes)相对丰度显著下降,G1C和G1CC小菜蛾肠道中变形菌门(Proteobacteria)相对丰度显著上升成为优势菌群,G1WC肠道中拟杆菌门(Bacteroidetes)成为优势菌群。在寄主植物上连续饲养3代后,与第1代相比,小菜蛾肠道细菌α多样性指数没有显著性改变,但在结球甘蓝和结球白菜上小菜蛾肠道菌群结构却发生了变化,相比G1C,G3C肠道中芽孢杆菌目(Bacillales)的相对丰度显著下降;相比G1CC, G3CC肠道中放线菌门(Proteobacteria)、芽单胞菌门(Gemmatimonadetes)和硝化螺旋菌门(Nitrospirae)的相对丰度均显著上升。【结论】取食人工饲料和不同寄主植物的小菜蛾幼虫肠道细菌多样性和群落构成存在显著差异,寄主植物对小菜蛾肠道微生物的结构组成具有重要的影响,且小菜蛾肠道微生物对寄主植物可能存在一个长期适应的过程。本研究为进一步探讨影响小菜蛾肠道细菌变化的因素,以及后续研究肠道细菌与寄主植物之间的互作奠定了良好的基础。     

小菜蛾咬食后青菜释放的挥发性物质成分和含量的变化

在虫害条件下,青菜释放出的挥发性化学物质成分较多．其中饱和烷烃类物质占多数,其次是芳烃类物质,其它为少量的不饱和烷烃、醛、醇、酮、酸和杂环化合物等．经小菜蛾取食危害的青菜释放的挥发性物质的量比未受损伤的青菜高3倍,且挥发性物质种类也多些．前者的挥发性物质多为分子量较小的物质,后者的挥发性物质多为分子量较大的物质．     

Laboratory evaluations of a wild crucifer Barbarea vulgaris as a management tool for the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae)

The term 'dead-end trap cropping' has recently been proposed to identify a plant that is highly attractive for oviposition by an insect pest, but on which offspring of the pest cannot survive. The potential of the wild crucifer Barbarea vulgaris R. Br. to allure and serve as a dead-end trap crop for the diamondback moth Plutella xylostella (L.), an important pest of cruciferous crops worldwide, was examined in laboratory experiments. When P. xylostella adults were provided with a dual-choice of plants of B. vulgaris, and Chinese cabbage Brassica campestris (L.), in one arena, adult moths laid 2.5-6.8 times more eggs on the former than on the latter. When P. xylostella adults were provided with a dual-choice of plants of B. vulgaris and common cabbage Brassica oleracea L., adult moths laid virtually all their eggs on the former and ignored the latter. Nearly all P. xylostella eggs laid on the three species of plants hatched successfully, but nearly all individuals on plants of B. vulgaris died as neonates or early instar larvae, while 87-100% of the larvae on Chinese cabbage and common cabbage survived to pupation. Dual choice tests with a Y-tube olfactometer showed that volatiles from B. vulgaris were much more attractive to P. xylostella adults than those from common cabbage. The results demonstrate that B. vulgaris has a great potential as a dead-end trap crop for improving management of P. xylostella. Factors that may influence the feasibility of using B. vulgaris as a trap crop in the field are discussed, and ways to utilize this plant are proposed.     

Comparative susceptibilities of diamondback moth (Lepidoptera: Plutellidae) and cabbage looper (Lepidoptera: Noctuidae) from Minnesota and south Texas to lambda-cyhalothrin and indoxacarb

The susceptibility of early instars of diamondback moth, Plutella xylostella (L.), and early (first and second) and late instars (third and fourth) of cabbage looper, Trichoplusia ni (Hübner), from Minnesota and south Texas, to indoxacarb and lambda-cyhalothrin was determined in the laboratory. Susceptibilities of the two species from the two geographical locations to indoxacarb and lambda-cyhalothrin varied greatly. P. xylostella from Minnesota was as susceptible to indoxacarb as those from south Texas, whereas both early and late instar T. ni from south Texas were significantly more tolerant to indoxacarb than those from Minnesota. The LC50 values of indoxacarb for early and later instar T. ni at 48 h from south Texas were 4.3- and 34.0-fold greater than those from Minnesota, respectively. Similarly, early instar P. xylostella and late instar T. ni from south Texas were significantly less susceptible to lambda-cyhalothrin than those from Minnesota. Percentage mortality of the two insect species caused by the two insecticides varied with time of exposure and generally exhibited similar patterns of responses to different concentrations for each insecticide.     

Effects of specialist parasitoids on oviposition preference of phytophagous insects: encounter–dilution effects in a tritrophic interaction

Abstract.  1. Host plant preferences of the female diamondback moth Plutella xylostella were studied.
2. Female moths preferred conspecific-damaged cabbage plants over undamaged cabbage plants. The performance of P. xylostella larvae on conspecific-infested plants did not differ significantly from that of larvae on undamaged plants.
3.  Cotesia plutellae , the specialist parasitoid wasp of P. xylostella larvae, displayed equal preference for plants with differing levels of host-larvae damage, and the wasp attacked only one or two hosts on average before leaving an infested plant, irrespective of the number of hosts on the plant. It is hypothesised that the oviposition preferences of P. xylostella females for host plants already damaged by conspecific larvae demonstrate an encounter–dilution effect against C. plutellae .     

Oviposition preferences of herbivores are affected by tritrophic interaction webs

Two tritrophic systems were experimentally coupled in the present study. One system consisted of a cabbage plant ( Brassica oleracea ), diamondback moth larvae ( Plutella xylostella ) and their parasitic wasp ( Cotesia plutellae ). The other system consisted of a cabbage plant, cabbage butterfly ( Pieris rapae ) larvae and their parasitic wasp ( Cotesia glomerata ). First, we demonstrated that parasitism by C. glomerata and C. plutellae increased and decreased, respectively, on plants infested by both herbivore species than on plants infested by their host larvae alone. We then demonstrated that adult Pl. xylostella oviposited preferentially on plants infested with Pi. rapae , whereas adult Pi. rapae revealed no significant preferences between uninfested plants or plants infested with Pl. xylostella . Based on the present results and those of our previous study, we discuss the oviposition preferences of herbivores in tritrophic contexts.     

INFLUENCE OF SUBLETHAL EFFECTS OF INSECTICIDES ON THE POPULATION DYNAMICS OF PLUTELLA XYWSTELLA AND ITS PARASITOID DIADEGMA EUCEROPHAGA IN THE FIELD

Abstract The larvae of Plutella xylostella feeding on cabbage plants treated by insecticides, nomolt (25 ×10^-6 and cypermethrin (20× 10^-6 were exposed to their parasitoid, Diadegma euerophaga in the field. The life table technique and the control efficiency (CE) were used to evaluate the sublethal effects of insecticides on the population dynamics of P. xylostella and D. euerophaga . The results showed that the CEs of nomolt and cypermethrin on D. eucerophaga were bigger than that on P. xylostella . Nomolt had a profound effects on D. eucerophaga by the food chain.     

Evaluating trap crops for diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

Potential trap crops for the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), were evaluated through a series of ovipositional preference and larval survival experiments in outdoor screenhouses in 2002 and 2003. Hosts examined as trap crops were glossy and waxy collards, Brassica oleracea L. variety acephala; Indian mustard, Brassica juncea (L.) Czern; and yellow rocket, Barbarea vulgaris (R. Br.) variety arcuata. More eggs were laid on the potential trap crops, with the exception of waxy collards, than on cabbage. When P. xylostella was offered multiple hosts at the same time, numbers of eggs laid on glossy collards, Indian mustard, and yellow rocket were 3, 18, and 12 times greater than on cabbage, respectively. Similarly, when P. xylostella was offered a single trap crop host and cabbage, numbers of eggs laid on glossy collards, Indian mustard, and yellow rocket were 300, 19, and 110 times greater than on cabbage, respectively. Our studies suggest differences in oviposition between the potential trap crops and cabbage were likely due to host volatiles, leaf morphology and color, or a combination of these factors, rather than to total leaf areas, leaf shape, or plant architecture. Two-choice tests with a Y-tube olfactometer indicated that plant volatiles were major factors in P. xylostella host preference. The percentage larval survival from egg to pupation was 22.2% on cabbage, 18.9% on waxy collards, and 24.4% on Indian mustard, whereas survival was significantly lower on glossy collards (6.7%) and yellow rocket (0%). Based on our tests, it seems that yellow rocket may be the best candidate for use as a trap crop for P. xylostella because it is highly attractive for oviposition, but larvae do not survive on it.