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℃。     

温湿度对斜纹夜蛾幼虫发育历期、取食量与生存率的影响

本文研究了温湿度对烟草最主要害虫之一斜纹夜蛾幼虫发育历期、取食量、日平均取食速率和存活率的影响.结果表明在试验温度范围内,除27C外,随温度的升高,斜纹夜蛾幼虫的发育历期缩短,取食量下降,日平均食叶速率增大,存活率提高;相对湿度对斜纹夜蛾幼虫发育历期呈显著负相关,对其取食量、日平均食叶速率和存活率呈显著正相关.温湿度对斜夜蛾幼虫发育历期、取食量、日平均取食速率以及存活率的关系表达式分别为D=66.6644-1.5411T-11.856H,S=49.5205-0.4595T+22.64H,V=-3.0317+0.1617T+3.002H,L=-0.526+0.0225T+0.5142H.     

温度及保幼激素类似物对烟蚜茧蜂羽化时间和羽化率的影响

[目的]研究不同温度及不同浓度保幼激素类似物对烟蚜茧蜂Aphidius gifuensis蛹期羽化时间和羽化率影响,探寻能延迟蚜茧蜂蛹羽化时间且保证较高存活率的最佳温度及类似物组合,为烟蚜茧蜂规模化生产与释放提供参考.[方法]采用液浸法,以对照(10％丙酮)及保幼激素类似物处理烟蚜茧蜂蛹,将其放入相对湿度为75％±5％...     

温度和烟草粉螟密度对麦蛾茧蜂觅食行为的影响

为明确温度和烟草粉螟密度对麦蛾茧蜂觅食行为的影响,设置15、20、25、30和35℃梯度温度,测定了麦蛾茧蜂在不同密度烟草粉螟5龄幼虫条件下的功能反应、寄生量和产卵量。结果表明,麦蛾茧蜂的麻痹量随温度的升高和烟草粉螟密度的增大而增大,其功能反应为Holling II模型;麦蛾茧蜂的瞬时攻击率（a）随温度的升高先增大后降低（25℃最大）,处理时间（T_h）随温度的升高而缩短;在30~35℃条件下麦蛾茧蜂对烟草粉螟的控害潜力（a/T_h和T/T_h）最大。麦蛾茧蜂的寄生量、产卵量和转化率均随温度的升高而增大,随烟草粉螟密度的增大而减小。当温度在30~35℃和烟草粉螟为5~10头/盒时,麦蛾茧蜂的寄生量、产卵量和转化率较高。本研究为大量饲养和利用麦蛾茧蜂防治烟草粉螟等仓储害虫提供了理论依据。     

烟蚜重寄生蜂-蚜虫宽缘金小蜂的行为学特性初步研究

蚜虫宽缘金小蜂为烟蚜茧蜂的体外寄生蜂。成蜂羽化的当天即可交尾产卵,雄蜂可多次交尾,雌蜂只交尾1次。未交尾的雌蜂进行产雄孤雌生殖。成蜂只在白天羽化,羽化高峰期为7：00～10：00,占羽化总数的63．6％。蚜虫宽缘金小蜂对烟蚜茧蜂的虫态具有选择寄生性,对老熟幼虫的选择性最强,相对寄生率最高,为66．8％。其次是预蛹期,相对寄生率为29．4％。成蜂具有趋光性、向上性和假死性,以寄主体液、蚜虫分泌的蜜露或花蜜为食物补充营养时,寿命可大大延长。     

补充糖源对储粮害虫优势寄生性天敌麦蛾茧蜂寄生效率的影响

利用优势寄生性天敌进行储粮害虫生物防治是解决化学防治面临挑战的重要途径之一。补充糖源是进行寄生蜂扩繁和增强寄生蜂寄生效率的有效方式。本研究以不同质量分数（10%、20%、30%、40%和50%）的葡萄糖、蔗糖和蜂蜜作为初羽化麦蛾茧蜂的补充营养,统计5天内寄主被寄生率、麦蛾茧蜂产卵量和羽化率,明确最有利于麦蛾茧蜂寄生的糖源种类和质量分数。研究结果表明,葡萄糖、蔗糖和蜂蜜质量分数分别为30%、10%、20%时,能在短期内显著提高麦蛾茧蜂的寄生率;葡萄糖、蔗糖和蜂蜜质量分数分别为30%、10%、50%时,麦蛾茧蜂5天内总产卵量最多,且3种糖类之间差异不显著;葡萄糖、蔗糖和蜂蜜质量分数分别为20%、30%、40%时,麦蛾茧蜂子代出蜂率最高,分别为92.26%、83.90%、78.80%;30%葡萄糖溶液能有效提高麦蛾茧蜂释放后前期的寄生率,且效果稳定。因此,将30%葡萄糖溶液作为麦蛾茧蜂释放前的补充营养,可有效提高麦蛾茧蜂的寄生效率。本研究结果可为科学实施储粮害虫生物防治提供可靠依据。     

烟蚜茧蜂对烟蚜的选择性寄生及雌蜂年龄对后代性别的影响

烟蚜茧蜂寄生烟蚜后对烟蚜的产仔量和寿命影响较大,一龄若蚜至成蚜被寄生后的平均产仔量分别下降100.0%、97.3%、95.9%、92.7%、89.5%,平均寿命分别缩短65.6%、58.9%、57.9%、49.4%、38.3%;在各龄烟蚜数量比相同,雌蜂与烟蚜比为1:100的条件下,烟蚜茧蜂对二龄、三龄烟蚜有较强的嗜好性,这种嗜好性与雌蜂年龄无关;羽化并交配过的烟蚜茧蜂雌蜂,在前5 d内产卵寄生烟蚜,其后代的雌雄比大于1,寄主烟蚜的龄期对烟蚜茧蜂后代性别的影响不大。      

烟蚜重寄生蜂种群动态初步研究

系统调查了烟田和繁蜂棚内烟蚜重寄生蜂的种类、数量组成和种群变动。结果表明,烟蚜重寄生蜂有蚜虫宽缘金小蜂、宽肩阿莎金小蜂和合沟细蜂3种。在烟田,重寄生蜂出现的时间较烟蚜茧蜂滞后25 d,但高峰期仅相差约5 d,这种在时间上滞后、数量上跟随紧密的效应是制约烟蚜茧蜂种群数量的重要因素之一。在全年繁蜂的繁蜂棚内,重寄生率最高达65.0%,烟蚜茧蜂的羽化率还不到1.0%,而在田间简易繁蜂棚内,重寄生率不超过10.0%。且均以接蜂后7～21 d内烟蚜茧蜂羽化率为最高,而重寄生率以接蜂后7～14 d的最低。因此,人工繁殖烟蚜茧蜂时,建议在田间繁蜂棚内进行短期的繁蜂,即以接蜂后7～14 d为最佳繁蜂周期。     

温度对蓼蓝齿胫叶甲生物学特性的影响

在人工气候箱中研究了不同温度条件下蓼蓝齿胫叶甲的生物学特性,结果表明,在18~27℃范围内,随着温度的升高,各虫龄蓼蓝齿胫叶甲的取食量、存活率以及成虫的产卵量和羽化率逐渐增加,温度与蓼蓝齿胫叶甲的取食量、存活率,成虫的产卵量和羽化率均呈极显著正相关,蓼蓝齿胫叶甲繁殖的适宜温度范围为24~30℃,以27℃最佳。     

虫害诱导烟草抗性对斜纹夜蛾生长和产卵选择的影响

  目的  探究不同品种烟草的虫害诱导抗性对斜纹夜蛾生长和产卵选择的影响。  方法  选取了野生种的八旦野生烟、地方品种的梁桥晒烟和选育品种的湘烟5号3个烟草品种,测试斜纹夜蛾幼虫取食不同品种烟草的对照组和虫害处理组后的生活史参数;观察斜纹夜蛾成虫对不同品种烟草的产卵选择偏好性。  结果  斜纹夜蛾幼虫取食诱导的烟草,对后续再取食的斜纹夜蛾存活率、发育历期、蛹质量、蛹期、羽化率和成虫体质量产生了不利影响,例如,虫害处理组的斜纹夜蛾存活率、蛹质量较对照组显著降低,两者分别相差1.27~2.60倍、1.25~1.54倍,这一不利影响在野生种和地方品种烟草上表现的更为明显。斜纹夜蛾成虫对不同烟草品种的产卵选择偏好性存在差异,其中最偏好在选育品种上产卵,其次为地方品种,最不喜野生种,且虫害处理组的产卵选择率均显著低于对照组。  结论  虫害诱导烟草抗性对斜纹夜蛾的生长和产卵选择产生了不利影响。      

Interactive effects of temperature and relative humidity on oviposition and development of Callosobruchus chinensis (L.) on azuki bean

The effects of three temperatures, 20 °C, 25 °C and 30 °C, and four relative humidity (RH) levels, 30–35%, 50–55%, 70–75%, and 90–95%, on oviposition and development of Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) were investigated. C. chinensis were introduced to 30 g azuki bean seeds (cultivar Hongeon) one day post emergence. Five pairs of male and female beetles were used for each combination of temperature and RH, and replicated ten times. The introduced adults were allowed to lay eggs for 72 h. Temperature significantly influenced oviposition with increased number of eggs at 30 °C. Relative humidity had no effect on egg laying. Development time was affected by both temperature and RH. Development time was shortest at 30 °C and 70–75% RH. Adult emergence rate was affected by both temperature and RH; adult emergence rate increased with the increase in temperature and RH (up to 70–75%) levels. The results suggest that rather than the interactive effect of temperature and RH, individual effects of temperature and RH on C. chinensis are profound and C. chinensis is likely to cause greater damage to azuki bean seeds stored at 30 °C and 70–75% RH.     

浅析温度和湿度对织物颜色的影响

色彩在生活中扮演着重要角色,从颜色的色相、纯度、明度三要素进行分析,探讨了温度和湿度变化对织物颜色的影响。结果显示温度对颜色的影响不明显,在湿度较小的环境下颜色变化较大。     

桑蚕丝胶变性条件探索研究

采用红外光谱法研究丝胶在不同温湿度下放置不同时间后的变性情况，提出了丝胶变性程度的红外光谱分级法。在此研究的温度范围内，丝胶变性速度主要取决于环境的相对湿度。湿度越高，变性越快，变性的程度越大。提出丝胶变性存在着一个极限程度。     

Feeding and egg-laying preferences of the sawtoothed grain beetle Oryzaephilus surinamensis: Beyond cereals and cereal products

The insect's response to various living substrates is an important determinant for their life history and demography reflected in their feeding and egg-laying preferences. However, research on polyphagous stored product insects such as the sawtoothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), are largely focused on cereal grains neglecting its alternative hosts. Therefore, this study examines the effect of a range of 16 host substrates including dry fruits, nuts, oil and legume seeds on insect development, survival, and adult emergence of the sawtoothed grain beetle, besides of also determining the feeding substrate weight loss. Overall, the feeding substrates exhibited a significant and different effect on O. surinamensis, except egg incubation time and length of the pupal period. The longest larval periods were observed on legumes followed by oilseeds and (dry) fruits. The highest survival and adult emergence were recorded on fruits and nuts, except raisin, but significantly lower than when fed on legume seeds, including soybean. The losses in fruits and nuts were higher, particularly on almonds and cashew. Larva development was inversely correlated to survival and adult emergence, which were positively correlated to substrate loss. Our study indicated that several non-grain commodities such as (dry) fruits and nuts are rather suitable substrates for the population growth of O. surinamensis, an additional concern for in international trade.     

高温冲击对柞蚕卵繁殖赤眼蜂的影响

本文研究了柞蚕卵繁殖的赤眼蜂于预蛹期和蛹期经历6h35℃和6h44℃高温单次冲击处理,对当代羽化出蜂率、雌性产卵力、单卵雌蜂比、寿命等4个指标和处理子代羽化率、单卵雌蜂比等2个指标的影响。研究结果表明：当赤眼蜂处于预蛹期和蛹期,各处理当代易受高温冲击影响,尤以44℃高温不利影响明显,主要表现在羽化出蜂率、寿命及雌性产卵力3项指标明显降低。总体来看,高温冲击对子代蜂各指标未表现出明显影响。     

温度对菜豆货架期水分损失影响的预测模型

目的:菜豆在货架期内易失水而导致品质下降。明确菜豆水分在一定的湿度范围,不同温度条件下的变化情况,可以预测菜豆的商业品质,从而有效地推测最佳销售时期。方法:在一定湿度范围内,通过调控环境中的温度条件建立菜豆水分变化的数学模型,分析菜豆在货架期的预售时间。试验中模拟了温度分别为15、20、25、30℃,相对湿度为70%~80%的不同货架期条件。结果表明:通过测定72 h内的失水率变化,以化学反应动力学和阿伦方程(Arrhenius)为基础,得到菜豆失水率和温度之间关系的预测模型(R2>0.98)。对该模型的验证试验表明,模型预测值和试验真实值拟合度高,利用模型能预测菜豆在货架期内水分损失的规律。结论:菜豆水分损失预测模型为M=(1 055.532e-2443.6/T)t,该模型可有效预测菜豆货架期水分散失情况,为菜豆在货架期预售时间提供理论依据。     

发酵条件对雪茄芯叶TSNAs及其前体物含量变化的影响

  目的   探究发酵条件对雪茄芯叶TSNAs及其前体物含量变化的影响。  方法   以茄芯原料什烟1号为材料,设置不同温度（temperature, T）与相对湿度（relative humidity, RH）互作试验,测定发酵前后烟叶样品中的TSNAs及其前体物含量的变化。  结果   1）不同发酵条件下烟叶TSNAs含量存在极显著差异,发酵后烟叶TSNAs含量可从1326.77 ng/g增至1511.60~5240.24 ng/g,增幅13.78% ~ 294.96%。2）发酵湿度对烟叶TSNAs含量的影响最大,贡献率达57.01%,随发酵湿度从70%增加至90%,烟叶TSNAs含量显著下降。3）温度对TSNAs的贡献率为28.33%,随发酵温度的增加,烟叶的TSNAs含量逐渐上升,尤其是超过42℃后,TSNAs含量显著增加。4）温度与湿度的交互作用对TSNAs含量影响较小,贡献率为14.66%。5）前体物生物碱与硝酸盐含量均随湿度的增加而增加,随温度增加,生物碱总量先降低后升高,硝酸盐含量则持续升高。  结论   生产中建议在45℃-RH 80%条件下发酵以抑制发酵过程中TSNAs的形成与积累。      

Survival and growth of epidemically successful and nonsuccessful Salmonella enterica clones after freezing and dehydration

The spread of epidemically successful nontyphoidal Salmonella clones has been suggested as the most important cause of salmonellosis in industrialized countries. Factors leading to the emergence of success clones are largely unknown, but their ability to survive and grow after physical stress may contribute. During epidemiological studies, a mathematical model was developed that allowed estimation of a factor (q) accounting for the relative ability of Salmonella serovars with different antimicrobial resistances to survive in the food chain and cause human disease. Based on this q-factor, 26 Salmonella isolates were characterized as successful or nonsuccessful. We studied the survival and growth of stationary- and exponential-phase cells of these isolates after freezing for up to 336 days in minced meat. We also investigated survival and growth after dehydration at 10°C and 82% relative humidity (RH) and 25°C and 49% RH for 112 days. Stationary-phase cells were reduced by less than 1 log unit during 1 year of freezing, and growth was initiated with an average lag phase of 1.7 h. Survival was lower in exponentialphase cells, but lag phases tended to be shorter. High humidity and low temperature were less harmful to Salmonella than were low humidity and high temperature. Tolerance to adverse conditions was highest for Salmonella Infantis and one Salmonella Typhimurium U292 isolate and lowest for Salmonella Derby and one Salmonella Typhimurium DT170 isolate. Dehydration, in contrast to freezing, was differently tolerated by the Salmonella strains in this study, but tolerance to freezing and dehydration does not appear to contribute to the emergence of successful Salmonella clones.     

Prediction of moisture gain and loss for packaged pasta subjected to a sine wave temperature/humidity environment

The loss or gain of moisture through a package depends on the sorption isotherm of the food material, the conditions of temperature and relative humidity at which it is stored, and the water vapour permeability of the packaging material. The water vapour permeability (WVP) characteristics of paperboard, polypropylene, and polyethylene used for pasta were determined at 30 to 45°C and from 11 to 85% r.h. Both temperature and relative humidity affected the water vapour permeability of all the three films. Paperboard showed a greater WVP at 30°C compared to 45°C due to a higher moisture content which swells the matrix. Thus, it did not follow the typical Arrhenius relationship of a higher permeability at higher temperature. Polyethylene and polypropylene, on the other hand, showed a higher WVP as the temperature was increased. A second degree polynomial was fitted to predict the WVP of paperboard as a function of the ambient conditions. It was found that the creases and end openings on a typical paperboard box increase the overall transmission rate by two times over that of paperboard alone, therefore reducing the shelf life to half under adverse conditions.
A dynamic mathematical model to predict mixture transfer for pasta packages under controlled unsteady state conditions of temperature and r.h. was developed and tested; good predictions were obtained.