猎物对巴氏钝绥螨生长发育和繁殖的影响

在(25±1)℃、90%RH以上、无光照实验条件下,以腐食酪螨和刺足根螨为猎物,研究了巴氏钝绥螨的生长发育和繁殖情况。结果表明,以腐食酪螨幼螨为猎物,巴氏钝绥螨可正常发育和繁殖,雌、雄成螨寿命分别为(34.250±1.361)和(23.950±1.606)d;以刺足根螨为猎物时,无法发育到成螨;成螨寿命明显缩短,雌、雄分别为(7.300±0.619)和(6.567±0.609)d,显著短于捕食腐食酪螨的巴氏钝绥螨,而且雌螨不能产卵。     

温湿度对腐食酪螨存活和繁殖的影响

研究了33种不同温湿度处理对腐食酪螨卵发育、孵化,成螨存活和繁殖的影响。结果表明：在15±1℃、20±1℃、25±1℃、30±1℃、35±1℃5种恒温下,相对湿度低于60％腐食酪螨几乎不能存活,高湿环境条件才有利于该种群正常繁衍。在适宜相对湿度范围,湿度与腐食酪螨成螨存活率关系显著,温度与腐食酪螨卵的发育历期、成螨日均产卵量关系极显著。     

土耳其斯坦叶螨的发育起点温度与有效积温

本文研究了土耳其斯坦叶螨 Tetranychus turkestani(Ugrou & Nikolski)在实验条件下的发育起点温度和有效积温。结果表明土耳其斯坦叶螨全世代发育起点温度和有效积温分别为雌螨10 .74 73℃和 16 4 .0 1日度 ,雄螨为 11.56 0 3℃和 113.2 9日度。在 15,2 0 ,2 5,30℃的恒温条件下 ,雌螨 1代平均历期分别为 35.15,19.0 5,11.0 4和 8.6 8天。     

二斑叶螨生物学研究

作者于1994—1995年对生活在花生和苹果叶上的二斑叶螨的生物学进行了研究。研究结果表明,以花生叶片为食科,该螨在25℃、30℃恒温条件和26．5℃-29．1℃变温条件下,其发育历期分别为11．04天,7．96天和8．64天。雌成螨在25℃、30℃恒温条件和23．8℃-30℃变温条件下,寿命分别是13．14天、10．5天和12．43天;产卵量分别是37．75粒、60,42粒和54．62粒。以苹果叶为食科,该螨在25℃、28℃和30℃恒温条件下,其发育历期分别是11．48天、9．56天和8．63天;雌成螨在25℃、30℃恒温条件和24.4℃-28．1℃变温条件下,其寿命分别为16．75天、14．78天和11.56天;产卵量分别是20粒、31.08粒和33．21粒。在花生上,该螨卵发育的起始温度是6．44℃,有效积温是69．79日度;虫期发育的起始温度是14．65℃．有效积温是74.98日度。在苹果上,卵发育的起始温度是4．61℃,有效积温是82,67日度,虫期发育的起始温度是12．41℃,有效积温是93．99日度。     

黄瓜钝绥螨对茶黄螨雌成螨和腐食酪卵的功能反应

研究黄瓜钝绥螨Amblyseius cucumeris 对茶黄螨Polyphagotarsonemus latus (Banks)雌成螨和腐食酪螨Tyrophagus putrescentiae卵的功能反应。结果表明,黄瓜钝绥螨的第1若螨,第2若螨,雌成螨捕食茶黄螨雌成螨和腐食酪螨卵的功能反应均属于Holling II型,其中,雌成螨的捕食能力最强,对腐食酪螨卵和对茶黄螨雌成螨的攻击系数a大,处理时间th短,第2若螨也具有较强的捕食能力,对静态的腐食酪螨卵比对动态的茶黄螨捕食能力强,黄瓜钝绥螨对茶黄螨雌成螨具有很强的捕食能力。     

萹蓄齿胫叶甲发育起点温度和有效积温

蓄齿胫叶甲 Gastrophysa polygoni (Linnaeus)是蓼科杂草蓄上的一种重要天敌昆虫。本文研究了该虫的发育起点温度和有效积温 ,结果表明 ,在 19～ 31℃范围内 ,该虫的发育历期随温度升高而缩短 ,反之则延长。经测定 ,卵的发育起点温度为 (10 .4 5± 0 .14 )℃ ,有效积温为 56 .2 4日度 ;幼虫期的发育起点为 (8.12± 0 .2 4 )℃ ,有效积温为 12 2 .2 0日度 ;蛹的发育起点为 (9.70± 0 .82 )℃ ,有效积温为91.70日度 ;产卵前期的发育起点和有效积温分别是 (16 .17± 0 .96 )℃和 52 .83日度 ;全世代的发育起点为 (12 .6 0± 0 .4 3)℃ ,有效积温为 2 90 .4 0日度     

腐食酪螨在不同温度和营养条件下生长发育的比较研究

在12.5℃、15℃、20℃、25℃和30℃恒温下,用啤酒酵母粉和玉米粉为饲料,测定了不同温度和饲料条件下腐食酪螨Tyrophagus putrescentiae各个发育阶段和世代的发育历期,获得其在各条件下的发育起点温度和有效积温。结果表明,在本文的实验温度范围内,该螨的发育历期与温度呈负相关,即随着温度的升高发育历期缩短。在各发育阶段不同饲料条件下发育起点温度和有效积温都有所差异。用啤酒酵母粉作饲料时,腐食酪螨的全世代历期为48.04天（12.5℃下）和8.41天（30℃下）,发育起点温度为10.18℃,有效积温为155.44 d·℃; 用玉米粉作饲料时,全世代历期为78.79天（12.5℃下）和10.77天（30℃下）,发育起点温度为10.52℃,有效积温为208.33 d·℃。以成螨体长和体宽为指标,比较了在各温度条件及不同饲料条件对其生长的影响,结果表明不同饲料对螨体大小有显著影响,温度的影响不明显。     

土壤中甲螨孳生与铬污染相关性研究

目的 :探讨土壤中甲螨孳生的种群数量与土壤铬污染之间的相互关系。方法 :于某大型化工厂周围土壤 10 m、1km、10 km及远郊农田土壤设立采样点 ,各采集 5 0份样本 ,每份样本采集 (10× 10× 10 )cm3的土壤 ,置 Tullgren电热分螨器中分离甲螨 ,计算甲螨在不同环境中的密度、丰度、优势属 ;同时用原子吸收光谱法分别测定化工厂周围土壤及远郊农田土壤样本中的铬含量。结果 :化工厂周围土壤总体甲螨的密度、丰度和优势度分别为 1975 7(131.71± 2 8.34)个 / m2、131.7个 /样本、嗜草甲螨、门罗点肋甲螨 ,远郊农田土壤甲螨的密度、丰度和优势度分别为 984 5 (6 5 .6 3± 18.36 )个 / m2、6 5 .6 3个 /样本、滑菌甲螨、嗜草甲螨、被盖头甲螨、棒菌甲螨、新小奥甲螨、普通尖棱甲螨 ,两者相比差异有显著性 (P<0 .0 1)。化工厂周围土壤及远郊农田土壤总体铬浓度分别为 (0 .2 5± 0 .0 7) mg/ kg、(0 .0 8± 0 .0 2 ) m g/ kg,两者相比差异有显著性 (P<0 .0 1)。化工厂周围土壤 10 m、1km、10 km、处甲螨的密度分别为 16 4 89(32 9.78± 31.2 2 )个 / m2、2 2 5 7(45 .14± 9.4 5 )个 / m2 、10 11(2 0 .0± 3.33)个 / m2 ,化工厂周围土壤样本的甲螨密度较高 ,与远效农田土壤相比 ,差异有显著性 (P<0 .0 1)。结论     

桑尺蠖的发育起点温度和有效积温

在室内恒温条件下测定了桑尺蠖的发育历期。对试验结果采用 2种方法计算 ,并用变异系数来检验。结果表明 ,对于早春出蛰后的越冬幼虫和非越冬代 ,用直接最优化法计算所得的结果更接近实际 ;越冬幼虫的发育起点温度 (C)为 (3.4± 0 .7)℃ ,有效积温 (K )为 4 97.5日度 ;非越冬代幼虫和全世代发育起点温度 (C)分别为 (4 .2± 1.4 )℃和 (6 .0± 1.3)℃ ,相应的有效积温 (K)分别为 50 5.8日度和 781.7日度。     

南美斑潜蝇发育起点温度和有效积温的研究

在恒温条件下 ,观察了不同温度对南美斑潜蝇LiriomyzahuidobrensisBlanchard生长发育的影响 ,并用直线回归法测得卵、幼虫、蛹和全世代的发育起点温度分别为 7 2℃ ,7 4℃ ,7 7℃和 7 5℃ ,有效积温分别为 4 0 8,98 6 ,1 4 0 5和 2 79 9日·度     

Collagen-like triple helix formation of synthetic (Pro-Pro-Gly)10 analogues: (4(S)-hydroxyprolyl-4(R)-hydroxyprolyl-Gly)10, (4(R)-hydroxyprolyl-4(R)-hydroxyprolyl-Gly)10 and (4(S)-fluoroprolyl-4(R)-fluoroprolyl-Gly)10.

For the rational design of a stable collagen triple helix according to the conventional rule that the pyrrolidine puckerings of Pro, 4-hydroxyproline (Hyp) and 4-fluoroproline (fPro) should be down at the X-position and up at the Y-position in the X-Y-Gly repeated sequence for enhancing the triple helix propensities of collagen model peptides, a series of peptides were prepared in which X- and Y-positions were altogether occupied by Hyp(R), Hyp(S), fPro(R) or fPro(S). Contrary to our presumption that inducing the X-Y residues to adopt a down-up conformation would result in an increase in the thermal stability of peptides, the triple helices of (Hyp(S)-Hyp(R)-Gly)(10) and (fPro(S)-fPro(R)-Gly)(10) were less stable than those of (Pro-Hyp(R)-Gly)(10) and (Pro-fPro(R)-Gly)(10), respectively. As reported by B?chinger's and Zagari's groups, (Hyp(R)-Hyp(R)-Gly)(10) which could have an up-up conformation unfavorable for the triple helix, formed a triple helix that has a high thermal stability close to that of (Pro-Hyp(R)-Gly)(10). These results clearly show that the empirical rule based on the conformational preference of pyrrolidine ring at each of X and Y residues should not be regarded as still valid, at least for predicting the stability of collagen models in which both X and Y residues have electronegative groups at the 4-position.     

Synthesis and luminescence properties of a blue-emitting Sr(3.5) Y(6.5) O(2) (PO(4) )(1.5) (SiO(4) )(4.5) :Eu(2+) phosphor

A novel blue‐emitting Sr_3.5Y_6.5O₂(PO₄)_1.5(SiO₄)_4.5:Eu²⁺ phosphor was synthesized via a solid‐state reaction. Powder X‐ray diffraction (XRD) analysis demonstrated that the Sr_3.5Y_6.5O₂(PO₄)_1.5(SiO₄)_4.5 host had a hexagonal crystal structure in the space group P6₃/m and unit cell parameters a = 9.418 Å, c = 6.900 Å. The as‐prepared phosphor showed a blue emission and all the main emission peaks were located at around 466 nm for different excitation wavelengths of 297, 333 and 391 nm. The temperature dependence of the photoluminescence property was investigated in the range 20–250 °C, and the emission intensity decreased to 71% of the initial value at room temperature on increasing the temperature to 150 °C. According to the classical theory of fluorescent thermal quenching, the activation energy (ΔE) for the thermal quenching luminescence of the as‐prepared Sr_3.45Y_6.5O₂(PO₄)_1.5(SiO₄)_4.5:0.05Eu²⁺ phosphor was determined to be 0.20 eV. Copyright © 2011 John Wiley & Sons, Ltd.     

Role of tfdC(I)D(I)E(I)F(I) and tfdD(II)C(II)E(II)F(II) gene modules in catabolism of 3-chlorobenzoate by Ralstonia eutropha JMP134(pJP4)

The enzymes chlorocatechol-1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase allow Ralstonia eutropha JMP134(pJP4) to degrade chlorocatechols formed during growth in 2,4-dichlorophenoxyacetate or 3-chlorobenzoate (3-CB). There are two gene modules located in plasmid pJP4, tfdC(I)D(I)E(I)F(I) (module I) and tfdD(II)C(II)E(II)F(II) (module II), putatively encoding these enzymes. To assess the role of both tfd modules in the degradation of chloroaromatics, each module was cloned into the medium-copy-number plasmid vector pBBR1MCS-2 under the control of the tfdR regulatory gene. These constructs were introduced into R. eutropha JMP222 (a JMP134 derivative lacking pJP4) and Pseudomonas putida KT2442, two strains able to transform 3-CB into chlorocatechols. Specific activities in cell extracts of chlorocatechol-1,2-dioxygenase (tfdC), chloromuconate cycloisomerase (tfdD), and dienelactone hydrolase (tfdE) were 2 to 50 times higher for microorganisms containing module I compared to those containing module II. In contrast, a significantly (50-fold) higher activity of maleylacetate reductase (tfdF) was observed in cell extracts of microorganisms containing module II compared to module I. The R. eutropha JMP222 derivative containing tfdR-tfdC(I)D(I)E(I)F(I) grew four times faster in liquid cultures with 3-CB as a sole carbon and energy source than in cultures containing tfdR-tfdD(II)C(II)E(II)F(II). In the case of P. putida KT2442, only the derivative containing module I was able to grow in liquid cultures of 3-CB. These results indicate that efficient degradation of 3-CB by R. eutropha JMP134(pJP4) requires the two tfd modules such that TfdCDE is likely supplied primarily by module I, while TfdF is likely supplied by module II.     

The helix-coil transitions of poly (dA)-poly (dT) and poly (dA-dT)-poly (dA-dT)

Helix–coil transition curves are calculated for poly (dA) poly(dT) and poly (dA-dT) poly (dA-dT) using the integral equation approach of Goel and Montroll.⁵ The transitions are described by the loop entropy model with the exponent of the loop entropy factor, k, remaining an arbitrary constant. The theoretical calculations are compared with experimental transition curves of the two polymers. Results indicate that the stacking energies for these two polymers differ by about 1 kcal/mole of base pairs. Also, a fit between theory and experiment was not possible for k > 1.70.     

Induction of in vitro flowering in Dendrobium Madame Thong-In (Orchidaceae) seedlings is associated with increase in endogenous N(6)-(Delta (2)-isopentenyl)-adenine (iP) and N (6)-(Delta (2)-isopentenyl)-adenosine (iPA) levels

We analysed the endogenous cytokinin levels of Dendrobium Madame Thong-In seedlings grown in vitro during vegetative and flowering-inductive periods. HPLC was used to fractionate the extracts and radioimmunoassay (RIA) was used for assay of zeatin (Z), dihydrozeatin (DZ), N(6)-(Delta(2)-isopentenyl)-adenine (iP) and their derivatives. Coconut water used in experiments was found to contain high level (>136 pmol ml(-1)) of zeatin riboside (ZR). Protocorms and seedlings cultured in medium with coconut water were found to contain 0.5-3.9 pmol g(-1) FW of the cytokinins analysed. Seedlings (1.0-1.5 cm) cultured in flowering-inductive liquid medium containing 6-benzyladenine (BA, 4.4 muM) and coconut water (CW, 15%) contained up to 200 and 133 pmol g(-1) FW of iP and iPA, respectively. These levels were significantly higher than all other cytokinins analysed in seedlings of the same stage and were about 80- to 150-folds higher than seedlings cultured in non-inductive medium. During the transitional (vegetative to reproductive) stage, the endogenous levels of iP (178 pmol g(-1) FW) and iPA (63 pmol g(-1) FW) were also significantly higher than cytokinins in the zeatine (Z) and dihydrozeatin (DZ) families in the same seedlings. Seedlings that grew on inductive medium but remained vegetative contained lower levels of iPA. The importance of the profiles of iP and its derivatives in induction of in vitro flowering of D. Madame Thong-In is discussed.     

Biology of Bactrocera (Zeugodacus) tau (Walker) (Diptera: Tephritidae)

The biology of the fruit fly Bactrocera tau, an important horticultural pest, was studied under laboratory conditions at 25°C and 60–70% relative humidity on Cucurbita maxima. The duration of mating averaged 408.03 ± 235.93 min. After mating, the female fly had a preoviposition period of 11.7 ± 4.49 days. The oviposition rate was 9.9 ± 8.50 eggs and fecundity was 464.6 ± 67.98 eggs/female. Eggs were elliptical, smooth and shiny white, turning darker as hatching approached, and measured 1.30 ± 0.07 mm × 0.24 ± 0.04 mm. The chorion has polygonal microsculpturing and is species-specific with polygonal walls. The egg period lasts for 1.3 ± 0.41 days. The duration of the larval period is 1.2 ± 0.42, 1.7 ± 0.48 and 4.0 ± 0.94 days for first, second and third instars, respectively. Pupation occurs in the sand or soil and pupal periods are 7.0 ± 0.47 days. The life cycle from egg to adult was completed in 14.2 ± 1.69 days; the longevity of mated females and males was 130.33 ± 14.18 and 104.66 ± 31.21 days, respectively. At least two to three generations were observed from June 2008 to June 2009.     

Spectroscopic investigations of Er(3+) :CdO-Bi(2) O(3) -B(2) O(3) glasses

This article reports on the optical properties of Er³⁺ ions doped CdO–Bi₂O₃–B₂O₃ (CdBiB) glasses. The materials were characterized by optical absorption and emission spectra. By using Judd–Ofelt theory, the intensity parameters Ω_λ (λ = 2, 4, 6) and also oscillatory strengths were calculated from the absorption spectra. The results were used to compute the radiative properties of Er³⁺:CdBiB glasses. The concentration quenching and energy transfer from Yb³⁺–Er³⁺ were explained. The stimulated emission cross‐section, full width at half maximum (FWHM) and FWHM × values are also calculated for all the Er³⁺:CdBiB glasses. Copyright © 2011 John Wiley & Sons, Ltd.     

Cationic (tripyrrinato)palladium(II) complexes

The formation of cationic palladium(II)complexes [TrpyPd^II]⁺X⁻ by salt metathesis of the respective trifluoroacetates with different salts of weakly coordinating anions X⁻ was investigated. With non-hydrolizable counterions, cationic mono- and dinuclear complexes are observed depending on the nature of the anion X⁻ and the solvent. The mononuclear cations, which are only formed with X = BAr^F, most probably carry a weakly bound molecule of dichloromethane at the fourth coordination site of Pd^II. When treated with diazoalkanes, only these are sufficiently reactive to form carbene complexes. Four- and five coordinate Lewis base adducts [TrpyPd^IIL]⁺ with L = CH₃NC, tBuNH₂, PMe₃, PEt₃ and PiPr₃ and [TrpyPd^IIL₂]⁺ with L = PMe₃ were prepared from the mononuclear cations [TrpyPd^II]⁺BAr^F−. From structural studies it becomes apparent, that the formation of stable five coordinate Pd^II species is restricted to medium size ligands and depends on the delicate balance between the steric influence of L and the strain, which is induced on the TrpyPd^II unit.