First results on synchrony between seasonal pattern of pheromone trap captures of cotton bollworm, <Emphasis Type="Italic">Helicoverpa armigera</Emphasis> and appearance of freshly emerged larvae on developing cobs of corn hybrids

Synchrony between development of five corn hybrid varieties of various seasonal growing rates (FAO numbers), seasonal flight pattern of male cotton bollworm, Helicoverpa armigera Hb. (Lepidoptera: Noctuidae), as monitored by pheromone traps, and the subsequent appearance of newly hatched larvae on developing cobs were studied at Mezőhegyes, South-Hungary, in 2003 and 2004. The phenological stages of corn hybrids were evaluated using the Iowa State University Scale (R₁–R₅), the flight of male moths was monitored by large capacity, funnel type of pheromone traps and the appearance of freshly hatched larvae on developing cobs were counted by visual inspection. The synchrony between the flight peak of male moths and the peak apperance of L₁ larvae on cobs was investigated by cross-correlation. In 2003 (average daily temperatures 20.7°C, average daily relative humidity 59.9% for the period of 4–18 July) “DK 391”, “DK 443” and “Maraton” hybrid varieties already reached silking stage (R₁) by the time when pheromone traps indicated a peak, at 7 July (peak capture at 3-day intervals 755.5 males/traps). The number of L₁ larvae peaked on developing cobs of these varieties also at 7 July (7.0, 4.0 and 3.8 larvae/50 cobs, respectively). The synchrony between the flight peak of male moths and the peak appearance of L₁ larvae on cobs was proven (LAG = 0). A rather similar trend was observed in “Vilma” hybrid variety: it reached R₁ stage at 7 July, and L₁ larvae appeared only a few days later (11 July, 3.8 larvae/50 cobs) (LAG = −1). However, “Maxima” hybrid variety reached R₁ stage 1 week later (14 July) than the time of peak captures. Here L₁ larvae peaked as late as at 18 July (0.8 larvae/50 cobs), i.e., only after the cob had reached R₁ stage (LAG = −3). A reverse order of dates of R₁ stage and peak capture was observed in “Maxima” in 2004 (average daily temperatures; 22.5°C, average daily relative humidities 72.6% for the period of 15 July–6 August): it reached R₁ stage at 19 July, while peak trap captures were recorded at 6 August (peak capture at 3-day intervals 20.5 males/traps). L₁ larvae were found in the highest numbers on 2 August (1.5 larvae/50 cobs), practically in synchrony with peak caputres (LAG = 0). “Káma” reached R₁ stage in 16 July, and L₁ larvae peaked at 2 August (1.3 larvae/50 cobs) (LAG = 0). On the rest of the corn varieties larvae were found only in too numbers for performing statistical analysis. We conclude that in order to predict the appearance of L₁ larvae, the phenological stage of the corn variety and the seasonal flight pattern of moths, as measured by large capacity pheromone traps, should be considered in combination. If the corn variety already reached R₁ stage, L₁ larvae appear on cobs as early as the time of peak flight of moths. However, no young larvae appear on cobs despite of high trap captures, until the corn reaches the R₁ stage. These findings are discussed in the view of specifying optimal timing of a pesticide application.     

中药烟熏剂的杀菌效果及其对产蛋率和孵化指标的影响

运用中药烟熏剂对种鸡进行带鸡熏蒸消毒,对其杀菌效果及其对种鸡产蛋性能、孵化效果的影响进行了试验观察。试验结果表明,中药烟熏剂具有较好的杀菌性能,对鸡舍空气细菌具有较高的灭菌率,提高孵化效果;同时具有使用方便的特点,不影响鸡的产蛋性能,也未有明显的临床应激反应。     

野鸭不同孵化阶段蛋壳内钙·磷·钾含量的变化研究

对不同孵化时期野鸭蛋壳内钙、磷、钾含量进行测定,结果表明:随着孵化时间不断延长,蛋壳内钙、磷、钾含量呈现一定的规律性。0～16胚龄,蛋壳内钙、磷变化相对较小,从16胚龄,钙含量突然降低,并持续至28胚龄,磷含量变化从8胚龄开始,16胚龄达最大,随后降低,22～28胚龄基本保持不变,同时各胚龄蛋壳中钙、磷比例也呈规律性变化;钾含量变化呈逐渐下降趋势。     

达里湖东北雅罗鱼受精卵在不同水体中的孵化试验

在赤峰市克什克腾旗达里诺尔渔场进行了达里湖东北雅罗鱼(华子鱼)受精卵在不同水体中的孵化试验及其鱼苗成活试验,试验表明:华子鱼受精卵在鄂尔多斯市柒盖淖水体中能够孵化且鱼苗成活良好,为达里湖华子鱼向内蒙古部分盐碱水域移植提供了科学依据。     

达里湖东北雅罗鱼受精卵在不同水体中的孵化试验

2005年4月30日至5月14日在赤峰市克什克腾旗达里诺尔渔场进行了达里湖东北雅罗鱼受精卵在不同水体中的孵化试验及其鱼苗成活试验,试验表明:东北雅罗鱼受精卵在鄂尔多斯市柒盖淖水体中能够孵化且鱼苗成活良好,为达里湖东北雅罗鱼向内蒙古自治区部分盐碱水域移植提供了科学依据.     

青海拉脊蝠蛾受精卵孵化率试验

通过比较不同因素对受精卵孵化率处理的影响,筛选出最合适的孵化条件,提高受精卵孵化率。采用青海拉脊蝠蛾受精卵,以饱满/不饱满受精卵、蒸馏水/盐水保湿、Hg溶液/蒸馏水3种处理和不同温度、湿度条件下进行孵化率试验。结果表明：青海拉脊蝠蛾受精卵孵化的最佳温度为15℃,最佳湿度为70%～80%;黑色发亮、饱满圆润的受精卵平均孵化率较高（40%）,经0.1%Hg溶液处理受精卵平均孵化率（35%）和蒸馏水保湿处理的受精卵平均孵化率（35%）较高。     

Larval group differentiation in Atlantic cod (Gadus morhua) inside and outside the Gullmar Fjord

The spatial and temporal occurrence of pelagic fish stages and their biological variability may affect their dispersal and survival, and ultimately fish recruitment. We collected Atlantic cod larvae at one station inside and at one station outside the Gullmar Fjord, eastern Skagerrak, in order to investigate small-scale larval group differentiation. Rectangular midwater trawl hauls were taken every 6 h (during 24 h) from three separate depth intervals between the surface and 70 m depth. About 80% and 20% of all larvae occurred above the halocline at the Fjord station and the Coastal station, respectively. Hatching (at both stations) occurred from the 3rd week in February to the 1st week in May, indicating that cod larvae were present for at least 5 months (from late February to early August). The length and hatch date frequency distributions of larvae from the surface layer were unimodal inside the fjord but bimodal outside the fjord. Analyses of seven microsatellite DNA loci indicated that larvae collected inside the fjord (where local spawning occurs) were genetically distinct from larvae sampled on the outside (F_ST = 0.0026). The two age cohorts outside the fjord were not, however, genetically different, nor were larvae collected at different depths. We conclude that small-scale variability of vertical concentration and larval life history variability should have consequences for interpreting models of larval dispersal and survival, and subpopulation structure analyses.     

5种中药对茄二十八星瓢虫孵化、产卵的影响

[目的]为有效防治茄二十八星瓢虫提供试验依据。[方法]通过孵化率试验和强迫取食试验测试黄连、黄柏、丹皮、百部、野菊花的水提取物对茄二十八星瓢虫卵的孵化、成虫产卵的影响。[结果]黄柏提取物处理的卵的孵化率为(48.7±4.7)%;野菊花和丹皮提取物的分别为(54.6±10.1)%和(61.7±24.5)%;黄连和百部提取物的分别为(89.7±4.3)%和(94.6±4.8)%。黄连提取物处理的成虫的产卵量为(89.3±7.6)粒;丹皮和野菊花提取物的分别为(106.7±12.1)和(110.3±11.2)粒;百部和黄柏提取物的分别为(154.2±9.8)和(165.3±20.3)粒。[结论]这5种中药水提取物对茄二十八星瓢虫卵的孵化、成虫产卵均有不同程度的影响,黄柏水提取物对其孵化率影响最为显著,黄连水提取物对其成虫产卵的抑制作用最为显著。     

达里湖鲫鱼受精卵孵化及鱼苗成活对比试验

2005年6月1-12日进行了达里湖鲫鱼受精卵在达里湖及其他5种不同水质条件下的孵化和鱼苗成活对比试验,试验表明:达里湖鲫鱼可在pH值、总碱度、总盐度分别高达9.84、63.5 mmol/L、6.92‰的水中正常孵化出苗,且苗能正常存活.     

温度、光照和土壤含水量对大豆胞囊线虫休眠卵孵化的影响

研究在实验室条件下不同温度,不同光照和不同土壤含水量对大豆胞囊线虫(SCN)休眠卵孵化的影响.分别测定了5个温度梯度下(18℃、21℃、24℃、27℃和30℃),7个光照条件下(0/24 h,4/20 h,8/16 h,12/12 h,16/8h,20/4 h和24/0 h)和7个土壤含水量(1%、5%、10%、15%、20%、25%和30%)条件下SCN休眠卵的孵化情况.结果表明:在供试温度18～30℃之间,休眠卵的孵化总量随温度升高而增加,30℃下孵化数量最大,达1316.33条.全光照处理的孵化量最大,达745.00条,4L/20D、12L/12D和20L/4D次之,而全黑暗处理的孵化量最少,仅为102.00条.土壤含水量在1%～30%之间,含水量为15%时孵化数量最大,达265.33,含水量在1%～15%时,孵化量随含水量的增加而增加,当含水量大于15%时,孵化量随含水量增加反而降低.研究证实在SCN休眠期可以通过提高温度增加光照时间来诱导卵孵化,以提高J2孵化数量,采用休眠胞囊接种应注意调节土壤含水量.