柑桔锈螨的生活史及其在不同寄主植物上的种群消长研究

研究结果显示,柑桔锈螨在温度为23~32℃、光周期(L∶D)为12∶12的条件下,卵期为2~4天,第一若螨期为2~3天,第二若螨期为3~5天,产卵前期为2~4天,成螨期为5~7天,1个世代的历期共12~19天;在广州沙田柚树上终年都有柑桔锈螨发生,6~10月发生严重,1月和12月为发生高峰期,其在红橙和四季桔树的发生规律与沙田柚树一致,但螨口数远远较沙田柚树的低。     

朱砂叶螨危害对豇豆幼苗叶绿素和蛋白质含量的影响

豇豆幼苗叶片受朱砂叶螨危害0～8 d内,叶绿素、蛋白质含量及组成随危害程度的加深均有不同程度的变化。在试验期内,受害叶片蛋白质含量随危害时间的延长稳定增加,与危害时间之间差异显著(P<0.05),在危害8 d时,两虫口密度之间也产生显著差异(P<0.05);在危害4 d后,受害叶片产生带8、9两条蛋白质谱带,且含量随危害时间的延长而增加;在实验期内,两处理叶片叶绿素a、叶绿素b及叶绿素总量均随危害时间的延长而下降,不同危害时间之间下降的幅度差异显著(P<0.05),另外,相同危害时间下两处理叶片叶绿素a、叶绿素b及叶绿素总量下降的幅度也随虫口密度的增大而增加,两虫口密度之间差异显著(P<0.05)。     

茄子品种(系)对侧多食跗线螨抗性聚类分析

 用田间种群密度、叶片为害指数和种群增长倍数 (实验室 ) 3个抗性指标作为评定标准 ,对 2 7个茄子品种抗侧多食跗线螨 Polyphagotarsonemus L atus( Banks)进行了系统聚类分析。结果表明 ,不同茄子品种对侧多食跗线螨抗性存在明显差异。相比较之下 ,丰研一号、种都万吨早茄、种都特别培育、成都墨茄、渝早茄 2号、湘研 2号和油罐茄7个品种为较强抗性品种 ;西安绿茄、种都皇太子、8819和湘研早茄 4个品种均为较易感品种 ;其余品种介于二者之间。同时表明 ,3个抗性指标之间相关性达极显著水平 ,因而 ,调查茄子品种抗该螨时选择 3个指标中的一个指标 ,既简便 ,又合理     

Effect of high-pressure hot-water washing treatment on fruit quality, insects, and disease in apples and pears: Part III. Use of silicone-based materials and mechanical methods to eliminate surface pests

Surface arthropods on pome fruits can cause export problems and disrupt commercial markets. Eliminating insects and mites on the packing line would be the last opportunity to provide for pest-free produce. In this study, an experimental packing line was used to evaluate techniques using different surfactant baths, pressurized water sprays, and styles of rotating brushes to remove field-collected and laboratory-reared grape mealybug, Pseudococcus maritimus (Ehrhorn) (Homoptera: Pseudococcidae), the diapausing two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) and the woolly apple aphid, Eriosoma lanigerum (Hausman) (Homoptera: Aphididae). The organosilicone Silwet L-77 was no more effective than a silicone-based food grade defoamer in aiding removal. Mechanical methods, such as the style of rotating brushes and pressurized sprays, were significantly effective in removing surface arthropods. No improvement in removal occurred when pressure was increased beyond 420 kPa. These techniques can be easily adapted to commercial facilities and will reduce the incidence of surface arthropods on marketed fresh fruits.     

The Effects of Different Cotton Varieties on the Carmine Spider Mite, Tetranychus cinnabarinus Boisd. (Acari: Tetranychidae)

The aim of this study was to delta differences in resistance to the carmine spider mite, Tetranychus cinnabarinus between cotton varieties grown in different areas. The effects of 8 varieties from several countries cm the development, longevity and fecundity of T-cinnabarinus were investigated in the laboratory. On leaves of the Egyptian cotton, Gossypium vitifolium, variety Giza 75, both females and males required a longer period to complete development than on the G. hirsutum varieties Coker 310 and MCH H. Female mites reared on the variety Coker 310 lived significantly longer and had the longest oviposition period. The largest total progeny per female was observed on the varieties Coker 310 and MCH H, the smallest on the varieties Aleppo 1 and Giza 75. The cotton varieties had no effect on the sex ratio of T. cinnabarinus. In general, the G. hirsutum varieties Coker 310 and MCH 11 appeared to be most supportive for T. cinnabarinus, whereas the G. vitifolium variety Giza 75 clearly showed reduced susceptibility.     

人工诱发条件下玉米自交系对红蜘蛛的抗性鉴定及抗感性分类

在人为控制和创造有利于玉米红蜘蛛发生、又能基本满足玉米正常生长发育需要的条件下,以来自国内外的74个重要玉米自交系为材料,进行了玉米自交系对红蜘蛛抗性的人工诱发鉴定。结果表明:不同的玉米自交系对红蜘蛛的抗性差异很大,其受害指数为0.06~0.91;叶片平均受害面积百分率与受害指数呈极显著正相关(r=0.97,P0.000 01)。这些自交系以其受害指数为基础,通过聚类分析划分为高抗、抗、中感、感和高感5个类群;自交系受害指数在类群间[高抗(0.11±0.02),抗(0.22±0.04),中感(0.35±0.03),感(0.49±0.05),高感(0.75±0.10)]差异极显著(P0.01)。在参试自交系中,ZH4改-1、BSSSS53-B、Q381等20个高抗红蜘蛛,KS2564、B47、1028S等19个抗红蜘蛛,掖478、冀35、PH6WC等18个中感红蜘蛛,郑58、B73、丹340等12个感红蜘蛛,昌7-2、B107、SK59、GNS12059和Mo17-476等5个高感红蜘蛛,其中,Mo17-476对红蜘蛛表现为易感。     

麦岩螨种群密度效应及防治指标的研究

研究结果表明：麦岩螨种群密度与其寿命、繁殖、迁逃等关系密切，随着种群密度的增加，麦岩螨卵的孵化率降低，初孵幼螨死亡率增加，雌成螨繁殖力下降，寿命缩短，扩散迁逃率增加，其危害密度为每株小麦２０￣４０头及其以下。防治指标为：返青期百茎螨量１４００头，危害指数为１％；拔节期百茎螨量６７００头，危害指数为６．５％。     

保护酶CAT在木薯种质抗螨中的功能初步研究

为验证保护酶CAT在木薯抗螨中的功能,测定分析了朱砂叶螨取食抗、感螨木薯种质后,CAT的表达量和酶活分别在木薯和朱砂叶螨中的变化情况。结果表明,一方面,朱砂叶螨取食1 d和8 d后,感螨木薯种质BRA900体内Me CAT1的表达量和CAT总酶活仅分别较为害前提高1.11倍、1.24倍和1.06倍、1.15倍,而在抗螨木薯种质C1115体内则分别较为害前提高2.75倍、2.62倍和2.36倍、2.38倍,均显著高于感螨木薯水平。另一方面,朱砂叶螨取食感螨种质BRA900 1 d和8 d后,保护酶Tc CAT的基因表达量和CAT酶活分别是为害前的1.13倍、0.98倍和1.02倍、0.99倍,而取食抗螨木薯种质C1115 1 d和8 d后分别降低至为害前的0.57倍、0.61倍和0.52倍、0.61倍,均显著低于取食感螨木薯水平。以上结果初步证实了保护酶CAT在木薯中被诱导能够缓解朱砂叶螨造成的氧化损伤,在朱砂叶螨中被抑制不利于取食为害,从而形成木薯抗螨性的功能。本研究为将CAT作为基因资源应用于抗螨木薯种质创制提供了理论基础。     

越冬柑桔锈螨的空间格局与抽样技术

应用6个聚集度指标分析了越冬柑桔锈螨成虫的空间格局,并对抽样技术进行了探讨。结果表明,越冬柑桔锈螨成虫的空间格局为聚集型;田间的最适抽样部位是植株上、中部叶片的叶腋处。提出了越冬成虫密度估计的序贯抽样方案。     

东方蜜蜂抗螨的试验研究

选择3群没有受大蜂螨感染，群势不同的东方蜜蜂蜂群，分别引入受大蜂螨感染的雄蜂幼虫脾，和工蜂幼虫脾，在蜂群底部放入收集蜂集废屑的纸板，以后每隔24小时，检查蜂群底部的落螨数；先2脾未受蜂螨感染的东方蜜蜂为幼虫脾放入受大蜂螨感染的西方蜜蜂蜂群里，让其受大蜂螨感染，72小时后还回原蜂群，工蜂为其清理蜂螨，结果表明：东方蜜蜂有很强的抗螨性，5－6天后，基本上可以清出，原引入的西方蜜蜂幼虫脾或东方蜜蜂幼虫脾上的所有蜂螨。