桑青尺蠖发育起点温度和有效积温研究

研究了桑青尺蠖各个虫态及全世代的发育起点温度 (C)和有效积温 (K) ,结果表明 ,该虫卵、幼虫、蛹、成虫及全世代的发育起点温度分别为 8 38、11 34、2 81、14 77和 11 6 3℃ ,有效积温分别为 86 0 5、341 86、197 90、48 5 3和 5 5 0 34日度     

栗蚕卵发育起点温度与有效积温研究初报

通过不同恒温处理对解除滞育的栗蚕卵进行加温暖种试验,以期测得栗蚕卵的发育起点温度与有效积温,为栗蚕的人工驯养及暖种提供依据.试验结果:初步测得栗蚕卵的发育起点温度为10.7℃(±2.6℃),孵化有效积温为194.5℃(±27.5℃),并发现在18℃、21℃、24℃恒温条件下,随区段温度升高,栗蚕卵孵化率有下降的趋势.     

樗蚕卵的发育起点温度和有效积温

基于开发利用野生泌丝昆虫资源的目的,在19、21、23和25℃4种恒温条件下,研究了樗蚕(Samia cynthia cynthia)卵发育的有效积温和发育起点温度。结果表明,樗蚕卵的发育起点温度为(7.364±1.53)℃,有效积温为(156.12±15.93)d.℃。     

栗蚕卵发育起点温度和有效积温的测定

栗蚕(Dictypoea japonica)是珍贵的野生泌丝昆虫资源。对解除滞育的栗蚕卵分别通过15、18、21、24℃恒温处理暖种,测定栗蚕卵的发育起点温度为(10.2±0.6)℃、孵化有效积温为(181.7±11.6)℃.d,表明一旦给予越冬后解除滞育的栗蚕卵9.6℃以上的温度条件,就可能使其开始发育,当有效积温达到170℃.d时便可孵化。该结果可作为栗蚕卵的人工越冬保护及暖种技术处理的理论依据之一。     

桑红叶螨发育起点温度和有效积温的测定应用

桑红叶螨是我省桑树的主要害虫之一，近年来在我省部份蚕区发生日趋严重，给蚕茧的产量、质量造成了较大的损失。由于我省地理条件复杂，该虫世代经过短，繁殖系数大，有效防治时间短，且很难准确地掌握预治适期，导致防治效果极差。为了使各地能有效地根据当地气候和环境条件准确地掌握防治时期，我们从1998年至2001年连续多次对桑红叶螨的卵幼螨、前期若螨、后期若螨进行了发育有效积温及起点温度测定，并对结果进行了中试验证，准确程度较高，为有效防治桑红叶螨提供了科学依据。     

狭翅雏蝗发育起点温度和有效积温的研究

在室外自然条件下用无芒雀麦（Ｂｒｏｍｕｓｉｎｅｒｍｉｓ）叶片饲喂狭翅雏蝗Ｃｈｏｒｔｈｉｐｐｕｓｄｕｂｉｕｓ（Ｚｕｂｏｖｓｋｙ）Ｕｖｒｏｖ，分别以直线回归法和直接最优法计算发育起点温度和有效积温，并与实际发生情况作了初步验证。全蝗蝻期发育起点温度为９．１７℃（直线回归法）或９．４１℃（直接最优法），有效积温为１９０．７０日度（直线回归法）或１７５．４４日度（直接最优法）。测定结果直接最优法计算结果较直线回归法更切合实际。     

中华真地鳖卵发育起点温度和有效积温的研究

在室内自然变温的条件下,利用有效积温法则公式和“最小二乘法”公式统计分析得出中华真地鳖(Eupolphaga sinensisWalker)卵的发育起点温度和有效积温。结果表明,中华真地鳖卵的发育起点温度为13.2℃,有效积温为807.51℃/d,有效积温预测式为N=(807.51±69.73)/[T-(13.20±1.36)],据此简要的叙述了在孵化中华真地鳖卵应注意的问题。     

中蜂工蜂封盖子发育起点温度和有效积温研究

本文在37℃、35℃、33℃和31℃,相对湿度为40%～50%的条件下,对不同温度对中华蜜蜂工蜂封盖子的发育历期、发育起点温度及有效积温进行研究。实验结果显示:①中蜂工蜂封盖子的发育历期,随温度的升高而缩短;②中蜂工蜂封盖子的发育起点温度为19.678℃;③中蜂工蜂封盖子的有效积温为4296.584677h℃;④封盖子的发育期(h)的预测算式为N=4296.58467(7/T-19.678)。     

意蜂蜂王封盖子发育起点温度和有效积温的研究

本文在29℃、31℃、33℃、35℃和37℃,相对湿度40%～60%下,对意大利蜜蜂蜂王封盖子的发育历期、发育起点温度和有效积温进行研究。实验结果显示:①蜂王封盖子的发育期随温度的升高而缩短;②发育起点温度为22.05℃,有效积温为2367.324h℃;③蜂王封盖子的发育期(h)的预测式为N=2367.324/(T-22.05)。     

豆无网长管蚜的发育起点温度和有效积温测定

将豆无网长管蚜在12、15、18、21、24和27℃及相对湿度80%的条件下进行饲养,结果表明,豆无网长管蚜1~4龄若虫在整个若虫期的发育起点温度和有效积温分别为1龄7.309 1℃,22.974 6日.度;2龄3.776 6℃,30.652 8日.度;3龄3.852 7℃,28.207 0日.度;4龄5.256 4℃,39.273 0日.度;若虫期4.874 3℃,125.848 7日.度。     

白刺夜蛾防治指标的研究

研究白刺夜蛾幼虫的食量和防治指标。结果表明,幼虫可分为5龄,各龄幼虫的日食量依次为4.81、12.39、37.56、130.68和483.25mg/头,幼虫期总食量2453.58mg/头。根据食量测定,研制的防治指标为39.7头/m²,经济允许损失水平为12.5%。     

Effects of two fentanyl constant rate infusions on thermal thresholds and plasma fentanyl concentrations in awake cats

Objective

To determine the pharmacokinetics and effects on thermal thresholds (TT) of two fentanyl constant rate infusions in awake cats.

垂穗披碱草种子的萌发适宜温度及温度阈值

摘要：以采集于甘肃省和青海省等地的8份垂穗披碱草(Elymus nutans)种质为材料,采用纸上发芽法在5、10、15、20、25、30、35和40 ℃ 8个恒温条件下,研究种子的萌发适宜温度和温度阈值。结果表明,所有供试垂穗披碱草种子在5～35 ℃条件下可萌发,在40 ℃不萌发;以20、25和30 ℃发芽最快,发芽率在3 d内可达最大值,根据种子萌发温度模型计算得出,供试垂穗披碱草种子萌发的最低温度(Tb)、最适温度(To)和最高温度(Tc)的平均值分别为4、24和38 ℃,种质间无显著差异(P＞0.05)。建议垂穗披碱草种子的适宜检验温度为20、25和30 ℃恒温,初次和末次的适宜统计时间分别为第3天和第11天。     

河西走廊荒漠草原白刺夜蛾生活习性及防治研究

为防制白刺夜蛾危害固沙植物白刺,保持河西走廊荒漠草原生态平衡,观察白刺夜蛾(Lei-ometopon simyrides Staudinger)害虫生活习性和天敌,观察显示白刺夜蛾在河西走廊荒漠草原上,1年发生3代,以蛹在土中越冬,主要以白刺(Nitraria spp)为食,幼虫期是其主要危害期。在干旱的荒漠草原上,6~8月3个月的平均降雨量超过38 mm,白刺生长茂盛,有利于白刺夜蛾幼虫的生长发育,使害虫数量大爆发,反之虫口密度急剧降低。不难得出最佳防治时间是每年的5月下旬至6月上旬。要充分利用和保护天敌以维持荒漠草原的生态平衡。     

草地蝗虫防治的经济阈值与生态阈值研究进展

进入21世纪以来,我国草地蝗灾连年发生,严重威胁着畜牧业发展和北方生态安全.经济阈值和生态阈值作为蝗虫防治的决策依据,是草地植保领域的重要研究课题之一.对国内外有关害虫防治经济阈值和生态阈值的概念及理论进行了概述整理,全面总结了我国在草地蝗虫防治经济阈值与生态阈值方面的研究进展,分析了2个阈值在实际应用中的关系.目前,...     

Challenges of thermal nociceptive threshold testing in the donkey

ObjectiveTo evaluate a thermal nociceptive threshold (TNT) testing device in the donkey, and the influence of potential confounding factors on TNTs.AnimalsTwo groups (Group 1 and Group 2) of eight castrated male donkeys aged 4–9 years, weighing 105–170 kg.MethodsTNTs were measured by heating a thermal probe on skin until an end-point behaviour (threshold temperature) or a cut-out temperature (51 °C) was reached. The withers and the dorsal aspect of the distal limb were used as sites for TNT testing. The effects on TNT of different confounding factors: the limb tested; rate of heating; and ambient temperature were evaluated. Data were analyzed using general linear models, and Mann-Whitney tests, p < 0.05 was considered significant.ResultsEnd-point behaviours (skin twitch or donkey looking at test device) when the thermal probe heated the withers were observed in approximately half of tests. TNT was (mean ± SD) 46.8 ± 2.85 °C. Subsequently the limb was evaluated as the test site in Group 1 followed by Group 2 donkeys; end-point behaviour being a foot-lift. In Group 1, 72% of tests ended in an end-point behaviour but the response rate was lower in Group 2 (20%), although TNTs were similar [(47.6 ± 3.3) and (47.3 ± 3.0) °C respectively] for responding animals. Rate of heating, ambient temperature and laterality (right or left) did not affect thresholds, but mean TNT was significantly higher in the forelimb (48.5 ± 2.8 °C) than the hind limb (47.4 ± 2.8 °C) (p = 0.012).ConclusionsWhen a thermal probe cut-out temperature of 51 °C was used in TNT testing in the donkey a high proportion of tests did not produce an identifiable end point behaviour. Higher cut-out temperatures damaged the skin. Under these conditions, thermal nociceptive threshold testing appears not be an appropriate analgesiometry technique in the donkey.Clinical relevanceTNT testing under these conditions is not suitable form of analgesiometry for donkeys.     

Early life thermal stress: impacts on future temperature preference in weaned pigs (3 to 15 kg)

Thermal stress can result in productivity losses, morbidity, and mortality if proper management practices are not employed. A basic understanding of the relationship between animals and the thermal environment is crucial to assess the environment’s impact on livestock performance. Therefore, the study objective was to evaluate whether different early life thermal stressors (ELTS) altered the temperature preference of pigs later in life. Twelve sows and their litters were randomly exposed to 1 of 3 ELTS treatments from 7 to 9 d of age: early life heat stress (ELHS; cycling 32 to 38 °C; n = 4), early life cold stress (ELCS; 25.4±1.1 °C without heating lamp; n = 4), or early life thermoneutral (ELTN; 25.4±1.1 °C with a heating lamp; n = 4) conditions. From 10 to 20 d, (weaning) all piglets were exposed to ELTN conditions. At weaning, pigs were randomly assigned to groups of 4 of the same sex and ELTS treatment. Temperature preference, where pigs freely choose a temperature, was assessed in 21 groups (n = 7 groups per ELTS treatment) using 1 of 3 thermal gradient apparatuses (22 to 40 °C). Testing began at 26 ± 1.3 d of age to give pigs time to acclimate to solid food after weaning and 1 group per ELTS treatment were tested simultaneously in each apparatus. Pigs were given 24 h to acclimate followed by a 24-h testing period. Behavior (active and inactive), posture (upright, sternal, and lateral lying), and location were documented every 20 min using instantaneous scan samples. Preferred feeding temperature was determined by the latency to empty a feeder in each location. Data were analyzed using PROC MIXED in SAS 9.4. A cubic regression model was used to calculate the peak temperature preference of pigs based on the temperature pigs spent most of their time. The preference range was calculated using peak temperature preference ±SE for each ELTS treatment group. Early life thermal stress altered where pigs spent most of their time within the thermal gradient (P = 0.03) with ELTN pigs preferring cooler temperatures (peak preference of 23.8 °C) compared with their ELCS exposed counterparts (peak preference of 26.0 °C; P < 0.01). However, ELHS exposed pigs (peak preference of 25.6 °C) did not differ in their temperature preference compared with ELTN or ELCS exposed counterparts (P > 0.05). In summary, ELCS exposure altered pig temperature preference later in life indicating that ELTS can alter temperature preference in pigs.