高温胁迫对红彩瑞猎蝽存活率及捕食作用的影响

为探明高温条件下红彩瑞猎蝽耐受能力及对斜纹夜蛾幼虫的控害潜能，在室内测定了红彩瑞猎蝽经不同高温胁迫48 h后的卵孵化率，5龄若虫羽化率，3、4、5龄若虫和雌、雄成虫存活率，评估了红彩瑞猎蝽不同虫态在高温条件下24 h内对斜纹夜蛾3龄幼虫的捕食能力。结果表明，高温胁迫对红彩瑞猎蝽各虫态的存活率、卵孵化率和羽化率有显著影响，经42℃处理48 h后红彩瑞猎蝽雌成虫和5龄若虫的存活率最高，达66.67%；红彩瑞猎蝽存活率、卵孵化率和羽化率在27～33℃时随温度升高而增加，在33℃后均随着温度升高而降低，36℃后存活率、卵孵化率和羽化率均下降明显。红彩瑞猎蝽各虫态在30～33℃范围对斜纹夜蛾的捕食量和捕食效能随温度升高而增大，在33～39℃范围，捕食量和捕食效能随温度升高而降低，红彩瑞猎蝽各虫态对斜纹夜蛾的捕食功能反应类型符合HollingⅡ型，随着猎物密度的增加，对猎物的搜寻效应逐渐减弱，个体间存在竞争和相互干扰作用。可见红彩瑞猎蝽对高温逆境有一定的耐受能力，其适宜生存的高温范围为33～36℃。     

东亚小花蝽产卵基质适合性研究

  背景和目的  东亚小花蝽（Orius sauteri）是一种具有应用潜力的捕食性天敌。筛选适宜东亚小花蝽人工规模化饲养的产卵基质。  方法  选取芸豆荚（Phaseolus vulgaris）、龙豆荚（Psophocarpus tetragonolobus (Linn.) DC.）和长豇豆荚（Vigna unguiculata subsp. sesquipedalis (L.) Verdc.）为产卵基质,比较东亚小花蝽在3种基质上的产卵量、孵化率及F₁代性比,及评价卵在10℃条件的耐藏性。  结果  （1）东亚小花蝽在芸豆荚上的单雌平均产卵量和孵化率最高,分别为92.52粒和90.47%;龙豆荚为89.90粒和90.16%,两者差异不显著,但显著高于长豇豆荚的78.70粒和80.49%;（2）10℃冷藏,芸豆荚和龙豆荚上的卵孵化率差异不显著,但显著高于长豇豆荚上的卵孵化率（P < 0.05）;（3）冷藏20 d时,芸豆荚上卵孵化率为70.22%,龙豆荚为67.77%,长豇豆荚为31.58%。  结论  芸豆荚和龙豆荚可作为东亚小花蝽规模化饲养的产卵基质。      

蠋蝽对斜纹夜蛾幼虫的捕食作用

为明确蠋蝽对斜纹夜蛾的捕食能力,在实验室条件下进行蠋蝽3~5龄若虫及成虫对斜纹夜蛾3龄幼虫的捕食能力测试,数据采用HollingⅡ功能反应模型进行拟合以明确其捕食潜能,利用Hassell模型拟合并测定了蠋蝽自身密度对斜纹夜蛾捕食作用的影响。结果表明,蠋蝽3~5龄若虫及成虫对斜纹夜蛾幼虫的捕食模型均符合HollingⅡ模型;蠋蝽3~5龄若虫和成虫瞬时攻击率顺序是3龄（1.873） > 雌成虫（1.329） > 4龄（1.187） > 5龄（1.125） > 雄成虫（0.828）;蠋蝽雌成虫的日最大捕食量最大,为13.699头。随着斜纹夜蛾3龄幼虫密度增大,蠋蝽的搜寻效应逐渐降低,雌成虫的搜寻效应明显大于其他虫态。随着天敌蠋蝽密度增大,干扰增强,平均捕食量随之降低。本研究显示出蠋蝽雌成虫对斜纹夜蛾具有较大的捕食潜能。     

环斑猛猎蝽对斜纹夜蛾低龄幼虫的捕食功能反应

为挖掘环斑猛猎蝽(Sphedanolestes impressicollis)对斜纹夜蛾(Spodoptera litura)的捕食潜力，在室内条件下研究了环斑猛猎蝽4龄若虫对斜纹夜蛾1龄、2龄和3龄幼虫的捕食功能、寻找效应、环斑猛猎蝽不同密度对捕食斜纹夜蛾的干扰效应以及捕食空间大小对环斑猛猎蝽捕食功能的影响。结果显示，4龄环斑猛猎蝽若虫对低龄斜纹夜蛾幼虫的捕食功能反应与Holling II模型相符，对1~3龄斜纹夜蛾幼虫的瞬时攻击率分别为0.979、0.999和0.164，处理时间分别为0.013、0.020和0.018 d，最大日捕食量分别为74.5、51.2和6.1头。4龄环斑猛猎蝽若虫的寻找效应与斜纹夜蛾低龄幼虫密度呈负相关，对斜纹夜蛾低龄幼虫的捕食作用率随自身密度的增加而下降。在捕食1龄斜纹夜蛾幼虫时，环斑猛猎蝽4龄若虫自身密度对其捕食能力干扰最大。因此4龄环斑猛猎蝽若虫对低龄斜纹夜蛾幼虫具有一定的捕食能力，可用于烟田斜纹夜蛾幼虫的绿色防控。      

南方小花蝽对烟蚜的数值反应

研究了南方小花蝽 (Oriussimiliszhong)各龄若虫在不同烟蚜密度下的捕食量与其发育速率的关系。结果表明 :在一定范围内 ,南方小花蝽各龄若虫的捕食量与其发育速率均为线性关系 ,符合Beddington模型。南方小花蝽各龄若虫的捕食量与产卵量也呈近线形关系。     

七种杀虫剂对烟蚜和南方小花蝽的毒力测定

为筛选出对南方小花蝽安全的药剂,测定了烟田常用7种杀虫剂对烟蚜成蚜（浸渍法）的毒力及南方小花蝽5龄若虫、雌成虫（药膜法）的毒性,并对南方小花蝽进行了安全性评价。结果表明,无论处理24 h还是48 h,对烟蚜成蚜的毒力、南方小花蝽雌成虫的毒性均是啶虫脒最高,LC₅₀分别为0.258和0.027 mg/L（24 h）、0.164和0.019 mg/L（48 h）,苦参碱最低,LC₅₀分别30.224和28.396 mg/L（24 h）、17.106和9.334 mg/L（48 h）;对南方小花蝽5龄若虫的毒性以溴氰菊酯最高,吡虫啉最低,苦参碱和阿维菌素相当,仅大于吡虫啉。综合考虑毒性和安全系数,防治烟蚜时选用苦参碱和阿维菌素能更好的保护南方小花蝽,达到协调化学防治和生物防治的目的。     

红彩瑞猎蝽与蠋蝽同类相残和集团内捕食作用分析

红彩瑞猎蝽和蠋蝽均为防治斜纹夜蛾的重要捕食性天敌,为明确两种捕食蝽不同虫态间的相互竞争关系,在室内条件下测定了红彩瑞猎蝽和蠋蝽种内同类相残和种间集团内捕食作用。结果显示,两种捕食蝽同类相残效应随着虫龄的增加而增加,红彩瑞猎蝽同类相残效应比蠋蝽更明显。两种捕食蝽在各个若虫和成虫时期均有集团内捕食现象,但卵极少被捕食。红彩瑞猎蝽各发育阶段的存活率均高于同样发育阶段的蠋蝽,尤其红彩瑞猎蝽1龄若虫存活率显著高于蠋蝽1龄若虫。提供猎物斜纹夜蛾时,红彩瑞猎蝽和蠋蝽各虫态的集团内捕食效应均明显降低。表明红彩瑞猎蝽为集团内捕食者,而蠋蝽为集团内猎物;两种捕食蝽组合应用于斜纹夜蛾的防治,捕食效果显著高于单一捕食蝽的效果。     

两种虫蛹冷藏存活率及其作为配对期食物对蠋蝽产卵的影响

针对蠋蝽规模化繁育中成虫配对期食物的优化,研究了黏虫蛹和黄粉虫蛹低温保藏后的存活率及其作为配对期食物对蠋蝽产卵的影响。结果表明,黄粉虫蛹和黏虫蛹在6℃保藏30 d后的存活率分别为89.33%、22.67%;蠋蝽配对期以冷藏黄粉虫蛹为食物,其总产卵量、单次平均产卵量、孵化率均显著高于以冷藏黏虫蛹为食物;蠋蝽对冷藏黄粉虫蛹的捕食偏好高于冷藏黏虫蛹。以冷藏的黄粉虫蛹作为配对期食物对提高蠋蝽人工扩繁效率具有重要意义。     

红彩真猎蝽对斜纹夜蛾幼虫捕食行为及室内扩散能力的研究

为掌握红彩真猎对斜纹夜蛾蝽捕食能力的强弱,采用培养皿和自制仪器装置目测观察,在室内条件下研究了红彩真猎蝽成虫和1~5龄若虫对斜纹夜蛾幼虫的捕食行为以及红彩真猎蝽1~5龄若虫及成虫的水平爬行能力和垂直攀爬能力。结果表明,成虫的取食时间随斜纹夜蛾幼虫龄期的增加而增加,4龄和5龄若虫的取食时间较其它龄期若虫的取食时间长。成虫的爬行时间随斜纹夜蛾幼虫龄期的增加而减少。随着红彩真猎蝽龄期的增加第一次刺入时间逐渐减少。随着红彩真猎蝽龄期的增加最长取食时间逐渐减少,取食量逐渐增多,红彩真猎蝽成虫和4-5龄高龄若虫的捕食能力最强。红彩真猎蝽5龄若虫及成虫的扩散能力很强,龄期越大室内扩散能力越强。这些研究结果对制定烟田释放红彩真猎蝽防治烟草害虫控制策略具有重要的理论意义。     

捕食性天敌红彩真猎蝽的生物学特性研究

为充分保护和利用烟田捕食性天敌红彩真猎蝽,调查研究了红彩真猎蝽成虫和若虫的形态特征和生活习性等生物学特性。结果表明,红彩真猎蝽能捕食烟田烟蚜、烟青虫和斜纹夜蛾等害虫;以斜纹夜蛾低龄幼虫为猎物饲养该天敌,其在广东南雄烟区一年发生2代,每代发育历期经历卵、1～5龄若虫和成虫,以成虫越冬;该天敌在15～35℃范围内均能正常生长发育,但发育历期随着温度升高而缩短。     

Mass rearing of Habrobracon hebetor Say (Hymenoptera: Braconidae) on larvae of the Indian meal moth, Plodia interpunctella (Lepidoptera: Pyralidae): effects of host density, parasitoid density, and rearing containers

Habrobracon hebetor Say (Hymenoptera: Braconidae) is a larval ecto-parasitoid of several species of Lepidoptera in the family Pyralidae including the Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), and other pyralid pests of post-harvest commodities and finished food products worldwide. Rearing methods for H. hebetor were investigated in a series of laboratory experiments designed to develop a mass rearing procedure for H. hebetor as a biological control agent against P. interpunctella and other stored products pyralid moths. The effects of parasitoid density, host density and the size of the rearing containers on adult progeny production and secondary sex ratio of H. hebetor were tested. In parasitoid density experiments, a density of eight male–female pairs of H. hebetor produced a higher number of progeny (188 adults) on 50 last-instar P. interpunctella larvae than the densities of one and two pairs of H. hebetor. Similarly, in a host density experiment, a density of 50 last-instar P. interpunctella larvae produced a significantly higher number of parasitoid progeny (160 adults) among the tested host densities when two pairs of H. hebetor were used. In experiments that assessed the size of the rearing containers, a glass jar with a volume of 236.6 ml (8 U.S. ounce “jelly jar”), produced a relatively higher number of parasitoid progeny (166 adults) than other sizes of containers when two pairs of H. hebetor were used. The parasitoid’s secondary sex ratio was female-biased in all experiments and there were no significant effects on sex ratio from variation in parasitoid density, host density, or size of the rearing containers.     

利用蜂蚜同接技术规模饲养烟蚜茧蜂

利用蜂蚜同接技术饲养烟蚜茧蜂,结果表明,蚜源的寄生率控制在47％左右,平均每株接蚜2.8头/株,饲养18d后最高繁蚜量可达11万头/m2,饲养23d后单位面积可获得4.9万头/m2以上的僵蚜量,繁蚜和繁蜂效益较高.     

Growth and survival of Vibrio parahaemolyticus in postharvest American oysters

Oysters at the retail stage of distribution generally contain greater densities of Vibrio parahaemolyticus than do oysters at harvest. The objective of this study was to determine the effects of postharvest storage at 26 and 3 degrees C on the growth and survival of naturally occurring V. parahaemolyticus in shellstock American oysters (Crassostrea virginica). Oysters were collected monthly from May 1998 through April 1999 from Mobile Bay, Alabama, and their V. parahaemolyticus densities were determined after 0, 5, 10, and 24 h of postharvest storage at 26 degrees C. After 24 h of storage at 26 degrees C, oysters were transferred to a refrigerator at 3 degrees C and analyzed 14 to 17 days later. V. parahaemolyticus numbers were determined by a direct plating method involving an alkaline-phosphatase-labeled DNA probe that targets the species-specific thermolabile hemolysin gene (tlh-AP) to identify suspect isolates. From April to December, when water temperatures at harvest were >20 degrees C, the geometric mean harvest density of V. parahaemolyticus was 130 CFU/g. When water temperatures were <20 degrees C, the geometric mean harvest density was 15 CFU/g. After harvest, V. parahaemolyticus multiplied rapidly in live oysters held at 26 degrees C, showing a 50-fold increase (1.7 log CFU/g) at 10 h and a 790-fold increase (2.9 log CFU/g) at 24 h (April through December). Average V. parahaemolyticus numbers showed a sixfold decrease (0.8 log CFU/g) after approximately 14 days of refrigeration. These results indicate that V. parahaemolyticus can grow rapidly in unrefrigerated oysters.     

绿肥在湘西烟田中的腐解和养分释放动态

为明确绿肥在植烟土壤中的腐解和养分释放规律,采用尼龙网袋法研究了光叶紫花苕子(Vicia villosa Roth var.)、箭舌豌豆(Vicia sativa L.)、紫云英(Astragalus sinicus L.)、黑麦草(Lolium perenne)在湘西烟田中的腐解动态。结果表明:绿肥中有机物腐解和养分释放量在翻压前两周分解速率最快,第3~7周分解速率中等,7周以后较慢。绿肥翻压前两周有机物平均每周的腐解率为12.50%~19.18%,碳、氮、磷、钾平均每周的释放率分别为13.05%~19.56%,20.08%~26.59%,17.86%~26.08%和16.97%~26.08%;第3~7周有机物平均每周的腐解率为6.16%~8.58%,碳、氮、磷、钾平均每周的释放率分别为6.23%~8.62%,5.71%~7.83%,4.47%~5.29%和7.01%~8.49%;7周以后有机物平均每周的腐解率为0.65%~0.96%,碳、氮、磷、钾平均每周的释放率分别为0.65%~1.48%,0.50%~1.09%,0.65%~1.36%和0.51%~1.14%。绿肥翻压后49 d时,有机物的累计腐解率为60.64%~70.57%,碳、氮、磷、钾累计释放率分别为62.17%~71.32%,75.68%~83.03%,70.61%~84.78%和73.88%~80.12%。绿肥养分在翻压后7周内以氮的释放量最大,黑麦草在翻压后两周内有机物腐解和养分释放慢于其他绿肥;箭舌豌豆在翻压后第3~7周内有机物腐解和养分释放慢于其他绿肥。绿肥翻压后的碳氮比(C/N)呈上升趋势,C/N达到24的最早时间为翻压后第7周。      

不同蜂蚜比的蜂蚜同接对规模化繁殖烟蚜茧蜂的影响

以漂浮育苗为载体,研究了不同蜂蚜比的蜂蚜同接后烟蚜茧蜂的繁殖效果。结果表明,蜂蚜比为1：100的蜂蚜作为蜂蚜同接的蚜源和蜂源,其初始寄生率为52.28%,按4头/株同接饲养25 d后,累计繁殖僵蚜量为261.66头/株,其寄生率高达97.3%,繁蜂效果最好。其次是蜂蚜比为1：200,再次是蜂蚜比为1：50。蜂蚜同接技术适用于烟蚜茧蜂的规模化繁殖,其繁蜂效果均优于先繁蜂再繁蚜的分接繁殖技术,在实际运用中蜂蚜比控制在1:100~1:200.     

Fenton/电-Fenton降解造纸废水中2,4-二氯苯酚的研究

探讨了Fenton/电-Fenton氧化法降解2,4-二氯苯酚影响因素及降解效果。结果显示:Fenton法的最佳工艺条件是pH值为2,3%H2O2投加量为2mL,FeSO4.7H2O投加量为0.30g,去除效率在80%-85%;电-Fenton法的最佳工艺条件是1mol/LNa2SO450mL,电压为5V,pH为4时处理效果最好,去除效率在90%-93%。对比分析研究的结果是Fenton法比电-Fenton法反应速率快、消耗的药品量大、产生的Fe(OH)3沉淀多、去除效果差,但是电耗低。     

A case for the standardization of protocols used in screening cowpea, Vigna unguiculata for resistance to Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae)

Cowpea cultivars Ife Brown, Maiduguri-A, Maiduguri-B and TVu 2027, were screened for resistance to Callosobruchus maculatus (F.) attack using different seed and insect densities. The number of eggs laid on the seeds and most other demographic variables increased with increase in insect density (number of females per 40 seeds). Although the same trend was observed with increase in seed density (seeds per 8 females), this was less predictable. However, the number of eggs per seed decreased significantly as seed density increased, but increased with increase in female density. Adult emergence increased significantly with increase in both insect and seed density while the growth index did not vary. Significantly more eggs were laid on the seeds of TVu 2027 (the resistant control) than on all the other cultivars when 20 or 40 seeds were available to 8 females, or at the lowest insect density (2 females per 40 seeds). However, percentage adult emergence and growth were higher on Ife Brown (susceptible control) than on TVu 2027 and the two Maiduguri cultivars. Measurements of percentage adult emergence and growth index indicated clear cultivar differences at all seed and insect densities. Also, although the loss in weight of seed increased with increase in insect density and decreased significantly with increase in seed density, meaningful differences in resistance among test cultivars were not always apparent at all densities. Based on these findings, we propose using 40 seeds and 2 pairs of adult beetles in screening cowpea for resistance. In addition, we conclude that % adult emergence, growth index and % weight loss are the most reliable indicators for resistance of cowpea to damage by this insect. The need to standardize experimental procedures used for host plant resistance work on storage pests of cowpea is emphasized.     

不同施氮量下采收时期对上部叶质量和经济性状的影响

在5个施氮水平上设置了3个采收时期进行大田试验,研究采收时期在不同施氮水平下对NC297上部烟叶物理、化学、经济性状及叶片色素含量的影响。结果表明,烤后烟叶总糖、还原糖的含量随采收时期的推迟显著减少;烟碱的变化趋势与施氮水平有关,在<30 kg/hm²的施氮水平下表现为先增后减的趋势,在30~60 kg/hm²的施氮水平下呈现增加趋势;施氮量<30 kg/hm²不适合推迟采收;施氮量为30、45和60 kg/hm²时推迟5 d采收的化学成分最为协调而且能取得最大的经济效益。施氮量为45 kg/hm²时推迟5 d采收烟叶的均价及上等烟比例最高,且感官质量最佳。     

Advancement of grapevine maturity in Australia between 1993 and 2006: putative causes, magnitude of trends and viticultural consequences

Background and Aims: Recent warming has accelerated phenological development of many crops. We quantified the rate of change in date of designated maturity (21.8°Brix), date of harvest, and sugar concentration of berries at harvest in Chardonnay, Cabernet Sauvignon and Shiraz between 1993 and 2006. Methods and Results: Data from 18 Australian regions indicated that: (i) the date of designated maturity advanced at rates between ?0.5 and ?3.1 days/year; (ii) trends in the date of designated maturity were unrelated to trends in yield; (iii) trends of monthly temperature ranged from negligible up to 0.19°C/year; (iv) the rate of change in date of designated maturity was correlated with rate of change of temperature for Chardonnay and Cabernet Sauvignon, but not for Shiraz; (v) harvest was accelerated at a rate between ?0.4 and ?2.4 days/year; (vi) the rate of change in harvest date for Chardonnay was commensurate with the rate of change in maturity, hence berry sugar concentration at harvest remained stable with time; and (vii) the advancement of harvest for Cabernet Sauvignon and Shiraz only partially offset the advancements in maturity, hence the increase in the concentration of berry sugar at harvest, up to ~0.3°Brix/year. Conclusions: Maturity advanced at rates between half and 3 days per year. On a temperature basis, these rates are comparable to long‐term rates reported for the northern hemisphere. Significance of the Study: This is the first report of time trends in phenology of grapevine in Australia and provides a benchmark for the industry.