棉花苗期棉蚜的二项式抽样设计及其精度分析(英文)

1991年4月—7月在河北省北京农业大学曲周试验站的棉花地进行苗期棉蚜（Aphisgossypii）的田间抽样调查,共收集到24组抽样数据。用泰勒幂法则对数据进行拟合,得到棉花苗期棉蚜为聚集分布。利用每样方（株）虫口不超过数阈值T（分别为0,1,2…9,10,15,20,30）头蚜虫的植株比例（PT）与种群密度（m,头／株）的关系,拟合经验关系式ln（m）=a十bln[-ln（PT）],通过对不同数阈值T的回归决定系数（r2）、种群的回归估计方差（Var（m））和抽样精度（用d估计）等进行综合分析,结果表明该蚜虫在数阈值T为15时,回归估计方差最小,回归决定系数和d值最大,因而T=15为该蚜虫的理想数阈值;而小的T值尤其是T为O时,由于产生太大的回归估计方差,很小的回归决定系数和d值即抽样的精度极低,因而不宜在实际中应用于棉蚜的二项式抽样设计。     

棉花苗期棉蚜的二项式抽样设计及其精度分析

基于棉花苗期棉蚜（Ａｐｈｉｓ ｇｏｓｓｙｐｉｉ）的２４组调查数据,利用每样方虫口不超过数阈值Ｔ（为０,１,２,…,９,１０,１５,２０,３０）头蚜虫的植株比例（ＰＴ）与种群密度（ｍ,头／株）的关系,拟合经验关系式１ｎ（ｍ）＝α＋ｂ１ｎ〔－１ｎ（ＰＴ）〕设计二项式抽样。通过对不同数阈值Ｔ的决定系数（ｒ＾２）、估计方差（Ｖａｒ（ｍ））和抽样精度（ｄ估计）等进行综合分析,结果表明该蚜虫在数阈值Ｔ为１５时     

Life history traits of Aphis gossypii Glover (Hom., Aphididae) reared on four widely distributed weeds

Variation in the life history traits of cotton aphids, Aphis gossypii Glover, reared on four widely distributed weeds, Ageratum houstonianum Mill., Bidens pilosa L. var. radiata Sch. Bip., Solanum nigrum L. and Spermacoce latifolia Aubl., were investigated. Cotton aphids were reared in the laboratory at 25°C. Each host plant had a distinct effect on aphid life history traits. Cotton aphids reared on S. nigrum had a significantly shorter developmental period, and age-specific fecundity peaked early. In contrast, cotton aphids reared on S. latifolia had a long developmental period and low age-specific fecundity. Cotton aphids that fed on B. pilosa and A. houstonianum displayed intermediate rates of growth and age-specific fecundity. Because the curves of age-specific fecundity ( m_x ) and age-specific net maternity ( l_x  m _x ) on each host plant were close together, development time and the pattern of age-specific fecundity were the major factors determining the population growth potential of the cotton aphid on each weed. As a result, the intrinsic rate of population growth for aphids reared on S. nigrum was significantly higher ( r_m =0.527 ± 0.011) than it was for aphids reared on S. latifolia ( r_m =0.194 ± 0.012).     

Responses of tree sap-feeding herbivores to elevated CO2

Five species of sap-feeding homoptera were studied on Fagus sylvatica and Acer pseudoplatanus and exposed to elevated concentrations of carbon dioxide (600 μL L^–1). The concentration of total soluble amino acids in foliage of F. sylvatica was unaffected by growing saplings in elevated atmospheric CO₂ concentrations. Although experiments on individual aphids indicated poorer performance of Phyllaphis fagi (fewer, smaller nymphs produced), resultant populations did not differ from those in ambient (350 μL L^–1) conditions. The area of beech foliage stippled by the leafhopper Fagocyba cruenta was similar at ambient and elevated CO₂ concentrations. The concentration of total amino acids and that of serine of A. pseudoplatanus foliage were significantly lower at elevated CO₂ concentrations. However, the relative growth rates of two aphid species Drepanosiphum platanoidis and Periphyllus testudinaceus and one leafhopper Ossiannilssonola callosa were not significantly different in elevated CO₂. No evidence was found that, under the conditions of these experiments, populations of aphids and leafhoppers will change as concentrations of CO₂ increase.     

The distribution of aphids in response to variation among individual host plants: Uroleucon rudbeckiae (Homoptera: Aphididae) andRudbeckia laciniata (Asteraceae)

Abstract. 1. An investigation was conducted to determine the effects of variation among individual plants of Rudbeckia laciniata L. on the distribution and abundance of the aphid Uroleucon rudbeckiae (Fitch).
2. Wild plants were examined repeatedly for up to 2¹/₂ years to obtain information about plant growth and flowering, and about aphid densities on individual plants.
3. Aphid densities on individual plants were positively associated with several measures of plant vigour, including height, growth since previous year, and occurrence of flowers.
4. The colonization of plants by alate aphids was more highly correlated with plant height than with plant exposure. Aphid densities on individual plants were more strongly associated with plant height than with number of colonists.
5. In all years there were many hosts which were never colonized by aphids. Some of these plants produced shoots but did not flower. Experimental infestation of these plants showed that they were unsuitable for aphid growth and reproduction. Some plants which did flower and which escaped aphid infestation were nevertheless suitable hosts. Previously unsuitable host individuals were able to support aphids when grown under glass-house conditions.     

Effects of sulfate and nitrate on K+ uptake and growth of wheat and cucumber

The uptake of K⁺ ion was studied in the roots of wheat ( Triuicum aestivum L. cv. GK Szeged) and cucumber ( Cucumis sativus L. cv. Budai csemege) seedlings grown in nutrient solution under nitrogen and sulfate stress conditions. Seedlings pretreated with 1 or 10 m M NaNO₃, absorbed more K⁺ than those treated with 0.1 m M NaNO₃. However, the posteffect of NaNO₃ was considerably influenced by the Na₂SO₄, treatment. The results suggest that, at least partly, a feed-back regulation of K⁺ uptake may occur. However, due to the high Na⁺ contents of the roots, a Na⁺ effect in this process cannot be excluded. The growth and dry matter yields of the roots and shoots were strongly influenced by the SO²⁻/₄ and NO⁻/₃ supply of the plants. Appreciable differences were experienced between wheat and cucumber seedlings. The optimum SO²⁻/₄ concentration of the growth solution for maximal growth varied considerably between the species, and was also different for the roots and the shoots in a given species.     

Host plant effects on the performance of the aphid Aulacorthum solani (Kalt.) (Homoptera: Aphididae) at ambient and elevated CO2

In future elevated CO₂ environments, chewing insects are likely to perform less well than at present because of the effects of increased carbon fixation on their host plants. When the aphid, Aulacorthum solani was reared on bean ( Vicia faba ) and tansy ( Tanacetum vulgare ) plants under ambient and elevated CO_2, performance was enhanced on both hosts at elevated CO₂. The nature of the response was different on each plant species suggesting that feeding strategy may influence an insect's response to elevated CO₂. On bean, the daily rate of production of nymphs was increased by 16% but there was no difference in development time, whereas on tansy, development time was 10% shorter at elevated CO₂ but the rate of production of nymphs was not affected. The same aphid clone therefore responded differently to elevated CO₂ on different host plants. This increase in aphid performance could lead to larger populations of aphids in a future elevated CO₂ environment.     

INSECTICIDE RESISTANCE OF COTTON APHID IN NORTH CHINA

Abstract  The cotton aphid ( Aphis gossypii Glover) is one of the most important pests infesting cotton in the cotton areas of North China. Since 1953 organophosphorus insecticides such as parathion and systox have been used to control the aphids for keeping up good yield of cotton. After several years. the concentration and the amount of spray were increasing in the field. In the early 1980's highly effective pyrethroid insecticides such as decis and sumicidin were largely imported into China. When first used 2. 5% decis emulsion was diluted in the ratio from 1:10000 to 1: 12000. However in 1985 the resistance of cotton aphid to pyrethroids increased by 171 times in general, 3230 times in some cotton fields. Thus it has prompted us to investigate the mechanism of resistance to insecticides and to search for the strategy to control the resistant aphids.
Experiments showed that the use of synergists including SV₁ (O, O-diethyl, O-phenyl phos-phorothionate) and PB has given evidence indicating mixed function oxidases (MFO). α-NA esterases and α-NA carboxylesterase are involved in the formation of resistance. The results also showed that the sensitivity of AChE to paraoxon in resistant aphids was lower than that in susceptible aphids.
Experiments showed that SV₁ was particularly synergistic to organophosphorus or pyrethroid insecticides and had played an excellent role in overcoming the resistance of cotton aphids to insecticides.     

Relative importance of Na+ and Cl– in NaCl-induced antioxidant systems in roots of rice seedlings

The present study examined the response of antioxidant systems to NaCl stress and the relative importance of Na⁺ and Cl^– in NaCl-induced antioxidant systems in roots of rice seedlings. NaCl treatment caused an increase in the activities of ascorbate peroxidase (APX) and glutathione reductase (GR) in roots of rice seedlings, but had no effect on the activities of superoxide dismutase (SOD) and catalase (CAT). There were detectable differences in APX and GR isoenzymes between control and NaCl-treated roots. Levels of activity for SOD and CAT isoenzymes did not change in NaCl-stressed roots compared with the control roots. NaCl treatment produced an increase in H₂O₂, ascorbate (AsA), dehydro-ascorbate (DHA), reduced glutathione (GSH), and oxidized glutathione (GSSG) levels. Treatment with 50 m M Na-gluconate (whose anion is not permeable to membrane) led to a similar Na⁺ level in roots to that with 100 m M NaCl. It was found that treatment with 50 m M Na-gluconate affected H₂O₂, AsA, and DHA levels, APX and GR activities, OsAPX and OsGR mRNA induction in the same way as 100 m M NaCl. These observed changes seem to be mediated by Na⁺ toxicity and not by Cl^– toxicity. On the other hand, it was found that NaCl, but not Na-gluconate and NaNO₃, caused an increase in GSH and GSSG levels, indicating that Cl^–, rather than Na⁺, is responsible for the NaCl-increased GSH and GSSG levels in roots of rice seedlings.     

Net CO2 exchange of Pinus taeda shoots exposed to variable ozone levels and rain chemistries in field and laboratory settings

Net CO₂ exchange rates (CERs) were measured in seedlings of two loblotly pine ( Pinus taeda L.) families following 6- or 13-week exposures to ozone (charcoalfiltered or ambient air + O₃) and acid rain treatments (pH 3.3, 4.5 and 5.2). Ozone exposures (14 or 170 nl l⁻¹) were made in open-top chambers, and in continously stirred tank reactors (14, 160 or 320 nl l⁻¹) located in the field and laboratory, respectively. The CERs of whole shoots were measured in an open infrared gas analysis system at 6 levels of photosynthetic photon flux density (0, 33, 60, 410, 800 and 1660 μmol m⁻² s⁻¹). Treatment effects were not consistent between field- and laboratory-exposed seedlings. Ozone-treated field seedlings exhibited statistically significant reductions in light-saturated CER of 12.5 and 25% when measured at 6 and 13 weeks, respectively. Laboratory seedlings exhibited mixed responses to O₃, with one family showing reduced CER only after 6 weeks of O₃ exposure and the other only after 13 weeks (O₃ >160 nl l⁻¹ for both). After 13 weeks of exposure, pH 3.3, and 4.5 rain treatments enhanced light-saturated CER by an average of 52% over that observed in seedlings exposed to the pH 5.2 treatment. Enhanced CERs due to acid rain were of the same magnitude (3–5 μmol CO₂g⁻¹ s⁻¹) as ozone-induced CER reductions. No differences in dark respiration were detected between treatments. Although ozone and acid rain treatments altered seedling CER, the differences were not translated into altered final plant dry weights over the 13-week exposure period.     

Binomial sampling as a cost efficient sampling method for pest management of cabbage root fly (Dipt., Anthomyiidae) in cauliflower

A binomial (presence–absence) sampling plan has been developed based on the relationship between the proportion of cauliflower plants having visible cabbage root fly eggs ( Delia radicum L.) exposed on the soil surface around the plant stem and the mean density of eggs per plant. The Kono–Sugino's model was fitted to a total of 125 population estimates, each based on 10 plant samples collected from cauliflower fields in 1994 and 1995 (P=0.001; R²=0.64). When the model was compared with an independent data set consisting of 39 population estimates collected in 1995, an analysis of covariance showed no significant differences between the regression lines. The efficiency of the binomial method was compared with absolute sampling in terms of relative precision and cost efficiency. The binomial method had a high coefficient of variation, RV ≈ 0.85, due to large biological error. In spite of this, binomial sampling was more cost efficient than the applied soil sampling when between 10 and 30 plants were examined for the presence of visible eggs.     

Acquisition and allocation of carbon and nitrogen by Danthonia richardsonii in response to restricted nitrogen supply and CO2 enrichment

Dry weight (DW) and nitrogen (N) accumulation and allocation were measured in isolated plants of Danthonia richardsonii (Wallaby Grass) for 37 d following seed imbibition. Plants were grown at ≈ 365 or 735 μ L L^–1 CO₂ with N supply of 0·05, 0·2 or 0·5 mg N plant^–1 d^–1. Elevated CO₂ increased DW accumulation by 28% (low-N) to 103% (high-N), following an initial stimulation of relative growth rate. Net assimilation rate and leaf nitrogen productivity were increased by elevated CO₂, while N concentration was reduced. N uptake per unit root surface area was unaffected by CO₂ enrichment. The ratio of leaf area to root surface area was decreased by CO₂ enrichment. Allometric analysis revealed a decrease in the shoot-N to root-N ratio at elevated CO₂, while the shoot-DW to root-DW ratio was unchanged. Allometric analysis showed leaf area was reduced, while root surface area was unchanged by elevated CO₂, indicating a down-regulation of total plant capacity for carbon gain rather than a stimulation of mineral nutrient acquisition capacity. Overall, growth in elevated CO₂ resulted in changes in plant morphology and nitrogen use, other than those associated simply with changing plant size and non-structural carbohydrate content.     

Effects of elevated carbon dioxide and ozone on aphid oviposition preference and birch bud exudate phenolics

The effect of atmospheric change on birch aphid ( Euceraphis betulae Koch) oviposition preference was examined and plant characteristics that are possibly responsible for the observed effects were investigated. It was hypothesized that the increasing concentrations of CO₂ and O₃ affect singly or in combination the oviposition of birch aphids via changes in host plant characteristics. Two genotypes of field-growing silver birch ( Betula pendula Roth) trees (clones 4 and 80), which were exposed to doubled ambient concentration of CO₂ and O₃, singly and in combination, in a 3-year open-top chamber experiment, were used in an aphid oviposition preference test. It was found that elevated CO₂, irrespective of ozone concentration, increased the number of aphid eggs laid on clone 4, but not in clone 80. Several flavonoid aglycones were identified from the exudate coating of birch buds. Although elevated CO₂ and O₃ affected these phenolic compounds in clone 4, the effects did not correlate with the observed changes in aphid oviposition. It is suggested that neither bud length, which was not affected by the treatments, nor surface exudate phenolics mediate birch aphid oviposition preference.     

Dissecting components of population-level variation in seed production and the evolution of masting behavior

Theory predicts that at higher trophic levels species are especially vulnerable to habitat fragmentation due to small population size and dependence on particular prey species. Using aphids as model organism, we tested the hypothesis that herbivore abundance increases in fragmented habitats as a result of reduced predator and parasitoid densities. In a 3 year-study, we examined the population dynamics of aphids with respect to host plant abundance and ant nest density in experimentally fragmented calcareous grasslands at two sites in the northern Jura mountains. Fragments of different size (area: 20.25 m², 2.25 m² and 0.25 m²) were isolated by a 5 m wide strip of frequently mown vegetation and corresponding control plots were situated in the adjacent undisturbed grassland. Aphid density was higher in fragments than in control plots. This was a combined result of a higher frequency of aphid-infested plants and larger aphid colonies in fragments than in control plots. Furthermore, a larger proportion of aphid colonies was ant-attended in fragments than in control plots. Aphid colonies were also more frequently visited by ants in fragments than in control plots in one of the 3 years. Parasitoid pressure on aphids was not influenced by the experimental fragmentation. Neither were aphid species richness and diversity affected by the fragmentation. Our study shows that even small-scale habitat fragmentation can have profound effects on the abundance of herbivorous insects. The effect on aphid density was consistent over 3 years and two sites with slightly different aphid communities.     

In situ responses to elevated CO2 in tropical forest understorey plants

1. Plants growing in deep shade and high temperature, such as in the understorey of humid tropical forests, have been predicted to be particularly sensitive to rising atmospheric CO₂. We tested this hypothesis in five species whose microhabitat quantum flux density (QFD) was documented as a covariable. After 7 (tree seedlings of Tachigalia versicolor and Beilschmiedia pendula ) and 18 months (shrubs Piper cordulatum and Psychotria limonensis, and grass Pharus latifolius ) of elevated CO₂ treatment ( c. 700 μl litre^–1) under mean QFD of less than 11 μmol m^–2 s^–1, all species produced more biomass (25–76%) under elevated CO₂.
2. Total plant biomass tended to increase with microhabitat QFD (daytime means varying from 5 to 11μmol m^–2 s^–1) but the relative stimulation by elevated CO₂ was higher at low QFD except in Pharus .
3. Non-structural carbohydrate concentrations in leaves increased significantly in Pharus (+ 27%) and Tachigalia (+ 40%).
4. The data support the hypothesis that tropical plants growing near the photosynthetic light compensation point are responsive to elevated CO₂. An improved plant carbon balance in deep shade is likely to influence understorey plant recruitment and competition as atmospheric CO₂ continues to rise.     

Induction of nitrate reductase in needles of Scots pine seedlings by NOX and NO3−

The possibility to induce nitrate reductase (NR; EC 1.6.6.2) in needles of Scots pine ( Pinus sylvestris L.) seedlings was studied. The NR activity was measured by an in vivo assay. Although increased NR activities were found in the roots after application of NO₃⁻, no such increase could be detected in the needles. Detached seedlings placed in NO₃⁻ solution showed increasing NR activities with increasing NO₃⁻ concentrations. Exposure of seedlings to NO_x (70–80 ppb NO₂ and 8–12ppb NO) resulted in an increase of the NR activity from 10–20 nmol NO₂⁻ (g fresh weight)⁻¹ h⁻¹ to about 400 nmol NO₂⁻ (g fresh weight)⁻¹ h⁻¹. This level was reached after 2–4 days of exposure, thereafter the NR activity decreased to about 200 nmol NO₂⁻ (g fresh weight)⁻¹ h⁻¹. Analyses of free amino acids showed low concentrations of arginine and glutamine in NO_x-fumigated seedlings compared to corresponding controls.     

Demographic parameters of cotton aphid, Aphis gossypii Glover （Homoptera： Aphididae） on five cotton cultivars

Life table parameters of the cotton aphid, Aphis gossypii Glover, were estimated on five cotton cultivars （‘ Sealand＇ ,‘Siokra＇ ,＇ Vararnin＇ ,‘ Bakhtegan＇ and ‘ Sahel＇ ）. Demographic parameters of the cotton aphid were assessed at 27.5 ± 1 ℃, 65% ＋ 10% RH and a photoperiod of 14：10 （L： D）h. The shortest developmental time for the nymphal stages was 5.5 days on ‘Siokra＇ and the longest was 6.1 days on‘ Sealand＇. The highest offspring per female was 29.6 on ‘Sahel＇ and the lowest was 15.3 on ‘Sealand＇. The rm values varied from 0.272 on ‘Sealand＇ to 0.382 （day^-1） on ‘Varamin＇. Jackknife estimates of the A. gossypii parameters on these cultivars indicated the greatest developmental rate and fecundity on ‘ Varamin＇ and the poorest on ‘ Sealand＇ cultivar.     

Symbiotic N2 fixation in a high Alpine grassland: effects of four growing seasons of elevated CO2

1. Increasing carbon dioxide concentration (E: 680 μl CO₂ litre^–1 vs ambient, A: 355 μl CO₂ litre^–1) around late-successional Alpine sedge communities of the Swiss Central Alps (2450 m) for four growing seasons (1992–1995) had no detectable effect on symbiotic N₂ fixation in Trifolium alpinum —the sole N₂-fixing plant species in these communities (74 ± 30 mg N m^–2 year^–1, A and E plots pooled).
2. This result is based on data collected in the fourth growing season showing that elevated CO₂ had no effect on Trifolium above-ground biomass (4·4 ± 1·7 g m^–2, A and E plots pooled, n = 24) or N content per unit land area (124 ± 51 mg N m^–2, A and E pooled), or on the percentage of N Trifolium derived from the atmosphere through symbiotic N₂ fixation (%Ndfa: 61·0 ± 4·1 across A and E plots) estimated using the ¹⁵N dilution method.
3. Thus, it appears that N inputs to this ecosystem via symbiotic N₂ fixation will not be dramatically affected in the foreseeable future even as atmospheric CO₂ continues to rise.     

Enumerative and binomial sequential sampling plans for soybean aphid (Homoptera: Aphididae) in soybean

Since the discovery of the soybean aphid, Aphis glycines Matsumura, in midwestern U.S. soybean, Glycine max L., in 2000, the aphid has become a significant economic pest. Basic information about estimating population density within fields is unknown. Therefore, we developed two sampling plans to efficiently characterize A. glycines densities. Enumerative and binomial sequential plans were developed using 89 data sets collected from 10 commercial fields sampled during 2001-2003. Re-sampling software was used to validate the enumerative plan on whole plant counts, based on Taylor's power law parameters (a = 9.157 and b = 1.543). For research applications, the enumerative plan was modified to provide an actual precision level of 0.10 (SE/mean), which resulted in an average sample number of 310 individual plants. For integrated pest management (IPM) purposes, we developed an enumerative plan with an actual precision of 0.25, which resulted in an average sample number of 38 individual plants. For IPM applications, the binomial plan will likely be more practical. Binomial plans were developed using two tally thresholds at five action thresholds. Final analysis of the operating characteristic curve for each plan indicated that the tally threshold of > or = 40 aphids per plant, and an action threshold of 0.837 (84% of the plants infested) provided the most correct treat (4%) and no-treat (95%) decisions, with very low incorrect treat (0.5%) and no-treat (0.5%) decisions. A tally threshold of > or = 40 aphids per plant and action thresholds of 84% of plants infested is equivalent to a mean density of 250 aphids per plant, a recently recommended economic threshold. Using this threshold, the minimum required sample number for the binomial plan was 11 plants.     

Comparison of field-based and indirect estimates of daily food consumption in larval perch and zander

Since bioenergetics models for 0+ fish have seldom been validated by field consumption estimates, field-based and indirectly estimated daily food rations were compared in larval perch Perca fluviatilis and zander Stizostedion lucioperca. Field-based estimates were calculated with linear and exponential evacuation rates based on gut fullness data during a 24-h cycle, with hourly field samplings instead of the normally recommended 3-h intervals. Indirect calculations used bioenergetics modelling with variable activity multipliers ( A ). Field-based estimates of daily rations ranged between 0·21 and 0·27 g g⁻¹ day⁻¹ in perch (mean L _T 13·1 mm) and 0·31–0·40 g g⁻¹ day⁻¹ in zander (mean L _T 10·6 mm). The higher values were calculated by using the exponential model. Daily rations calculated by bioenergetics modelling with A = 1 were only slightly higher than direct estimates in both species. However, if A values >1 were used, calculated daily rations were substantially higher than direct estimates. Estimates of daily ration based only on every third value ranged between 41 and 72% compared with 1-h intervals, mainly because of lower estimates of evacuation rate.