烟蚜茧蜂对麦田蚜虫的防治效果

为发掘利用麦田麦蚜自然繁育烟蚜茧蜂的潜力,建立蚜虫生态区域联防联控体系,以麦田自然发生麦蚜为防控对象,在麦田中释放单位面积不同数量的烟蚜茧蜂,调查并分析了释放烟蚜茧蜂与化学药剂处理和空白对照田块烟蚜茧蜂对麦蚜的寄生率、麦蚜虫口减退率、防治效果以及小麦产量指数等参数.结果显示,在麦田中麦蚜平均数量达到300头/百株时,烟...     

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。     

我国烟蚜茧蜂的研究进展

烟蚜茧蜂是烟蚜的一种重要寄生性天敌,对烟蚜的自然控制力较强。本文就烟蚜茧蜂的生物学、生态学及其应用等的研究进展作了较详尽的综述。生物学方面主要论述了烟蚜茧蜂的交配、寄生,发育,产卵,体色,性比,越冬,成蜂寿命及其对寄主生命活动的影响,生态学方面主要论述了烟蚜茧蜂的天敌以及气体因子、烟草长势和化学农药对其的影响。     

烟蚜茧蜂感器的扫描电镜观察

烟蚜茧蜂(Aphidius gifuensis)是蚜虫尤其是烟蚜(Myzus persicae)的常见重要寄生性天敌,烟蚜茧蜂感器的研究为其在寄生时的功能提供理论依据。本文运用扫描电镜技术,对烟蚜茧蜂的触角、复眼、口器、足上的重要感器形态与超微结构进行了系统研究。研究发现烟蚜茧蜂主要有 6种类型的感器:板形感器、刺形感器、毛形感器、锥形感器、Böhm氏鬃毛和膜状中垫。雌、雄蜂的感器差异不明显。触角鞭节上感器的种类和数量最多。毛形感器的数量最多且分布最广,Böhm氏鬃毛只分布在触角基节窝和足基节端部。      

烟蚜与烟蚜茧峰相互关系研究

研究结果表明，烟蚜茧蜂对烟蚜呈典型的Holling－Ⅱ型功能反应，参数a＝3．698／罩·天．Th＝0．0174天；该蜂对烟蚜生长发育和繁殖的影响因被寄生时蚜虫龄期不同而异，而蜂幼虫的发育不受寄生时蚜虫龄期的影响。当1～2龄蚜虫被寄生时，一般不能发育到成蚜期产蚜：从2龄中期起，蚜虫的生殖力和种群内禀增长率rm随着被寄生蚜虫龄期的增大而上升。由此可见，被寄生时蚜虫虫龄大小对蚜茧蜂寄生效果起着决定性的作用，寄生时蚜虫龄期越大，寄生作用越不明显。     

几种杀虫剂对烟蚜茧蜂搜索烟蚜行为的影响

利用Y形嗅觉仪观测了4种杀虫剂影响烟蚜茧蜂对烟叶及烟蚜复合体的选择行为.结果表明,在正常生长状况下,烟叶释放的挥发物对烟蚜茧蜂无明显引诱作用,而烟叶受到蚜虫为害后所释放的挥发性次生物质则对烟蚜茧蜂有明显的招引作用;在杀虫剂处理后,20％康福多、3％莫比郎乳油和40％氧乐果乳油会抑制烟蚜茧蜂的搜索行为,但氯氰菊酯则明显有...     

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。      

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.     

烟蚜茧蜂规模繁殖中烟蚜越冬寄主筛选

烟蚜越冬种群保育对保障烟蚜茧蜂规模繁殖具有十分重要的意义。通过接种烟蚜与烟蚜茧蜂,对玉溪地区8种不同寄主植物上烟蚜的增长数量、烟蚜茧蜂寄生烟蚜后形成僵蚜的体重进行了比较。结果表明,接种后,油菜、白萝卜、红萝卜上烟蚜数量以及僵蚜体重均可达到烟蚜茧蜂繁殖技术指标要求,可作为烟蚜茧蜂规模化繁殖体系中烟蚜的理想越冬寄主。     

烟蚜茧蜂繁蜂棚蚜霉病病原鉴定及防治研究

为探明繁蜂棚中蚜霉病的病原种类及防治技术,采集繁蜂棚中感病蚜虫和空气中的真菌,通过显微形态学和转录间隔区（ITS）扩增证实繁蜂棚内寄生蚜虫的病原真菌为蚜虫枝孢霉（Cladosporium aphidis）;密封试验箱内的消毒试验结果表明:在0.5 g/m3和1 g/m3剂量下,三氯异氰尿酸的总杀菌率可达92.31%和92.31%,对蚜虫枝孢霉的杀灭率分别达80.00%和83.33%;二氧化氯的总杀菌率可达97.88%和83.35%,对蚜虫枝孢霉的杀灭率分别达100%和93.33%;利用含三氯异氰尿酸钠的熏蒸剂熏蒸繁蜂棚,对蚜霉病的防治效率达69.65%。      

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.     

烟田常用杀虫剂对烟蚜茧蜂的毒力及其保护酶的影响

为了筛选对烟蚜茧蜂安全性高的药剂并明确烟田常用杀虫剂对烟蚜茧蜂保护酶的影响,测定了3种烟田常用杀虫剂对烟蚜茧蜂成虫的毒力以及不同浓度的吡虫啉对烟蚜茧蜂成虫体内超氧化物歧化酶、过氧化物酶和过氧化氢酶活性的影响。结果表明,杀虫剂对烟蚜茧蜂成虫的毒力大小顺序为:啶虫脒 > 高效氯氟氰菊酯 > 吡虫啉;从不同浓度的吡虫啉对烟蚜茧蜂生命活动和防御机制的影响来看,除LC₁₀浓度吡虫啉促进烟蚜茧蜂成虫体内POD活性提高和3个浓度处理后12 h成虫CAT活性显著提高外,其余处理浓度和时间对3种酶的活性呈现抑制作用。此结果为探明烟蚜茧蜂对杀虫剂的防御机制提供了一定的理论依据。     

食用油气味的研究方法及展望

概括了近几年来国外在食用油气味研究中主要使用的一些研究方法,着重阐述了研究中涉及的提取和分析方法,以及感官分析和人机互动分析在研究挥发组分对食用油气味贡献中的应用,并对我国食用油气味研究现状进行总结及展望。     

Effects of various glucogenic sources on production and metabolic responses of dairy cows fed grass silage-based diets

Four rumen cannulated Finnish Ayrshire cows in midlactation were used in an experiment designed as a 4 x 5 incomplete Latin square with 2-wk periods to compare effects of glucogenic substrates on grass silage-based diets. The five treatments were continuous infusions of 1) water (control), 2) casein 300 g/d, 3) glucose 300 g/d, 4) propionic acid 247 g/d, and 5) barley starch 270 g/d. Substrates were infused either into the rumen (propionic acid) or into the abomasum (other substrates). As a basal diet, cows were fed a formic acid treated grass silage ad libitum (digestible organic matter 690 g/kg dry matter [DM], crude protein [CP] 131 g/kg DM) and a barley-rapeseed concentrate (CP 141g/kg DM) at a rate of 7 kg/d. Production responses to glucogenic substrates other than casein were negligible, suggesting that glucose supply of the cows did not primarily limit milk production. However, with casein cows produced significantly more milk, milk protein, and lactose than with other glucogenic substrates. Casein increased urea and essential amino acid (EAA), and decreased nonessential AA (NEAA) in arterial plasma compared with other substrates, suggesting that casein provided precursors both in terms of NEAA for gluconeogenesis and EAA for milk protein synthesis. This puts forward that providing the AA needs of the mammary gland for milk protein synthesis are met, glucose supply may become the next limiting factor for milk protein synthesis in cows fed diets based on restrictively fermented grass silage. The limited supply of AA from the basal diet, and possibly the low production levels of cows partly invalidated the hypothesis of monitoring differing glucogenic substrates for grass silage-based diets.     

Effects of different deodorising processes on the off‐odour compounds and gel properties of common carp surimi

In order to improve the utilisation of the common carp (Cyprinus carpio), the effects of deodorising agents [NaCl, β‐CD, malic acid (MA) and hawthorn extract (HE)] on the volatile compounds of common carp mince and its surimi gel properties were investigated. In total, thirty‐two volatile compounds were identified, seven of which were considered the main compounds of off‐odour, using HS‐SPME‐GC‐MS and OVA analyses. HS‐SPME‐GC‐MS analysis showed that MA and HE removed 84.51% and 77.18% off‐odour compounds, respectively. Three relaxation components (T₂₁, T₂₂, T₂₃) were found in surimi, and their amounts were not affected by deodorising; however, the relaxation time of major component T₂₂ was significantly increased. Surimi deodorised by HE had the highest gel strength because of its increased breaking displacement; however, a slight decrease in whiteness was observed. Thus, appropriate levels of HE could improve the palatability of surimi.     

熟鱼silurus(Silurus glanis)的风味:通过感官分析和收集方法的比较来评价流体萃取物的风味特征

研究来自法国两个不同饲养环境的silurus(Silurus glanis)鱼的风味,对于熟鱼肉进行感官鉴评.通过流体萃取物的风味特征对其进行风味评价.比较了两种收集方法.两种养殖条件对熟鱼肉的风味有影响.在室外不进行换水饲养两年对比于在室内活水饲养一年发现鱼肉中干草味、青草味和热牛奶味较强,霉味、煮鸡蛋味和煮白菜味较弱.用铁氟龙容器收集风味物质提取物,比用玻璃长颈瓶收集风味描述更强,显示了流体萃取法与熟鱼风味分析的相关性.