龟纹瓢虫对棉蚜的捕食行为

为探讨天敌对害虫的捕食作用机制,充分发挥生物防治的作用,本文从捕食能学角度,系统地观测了龟纹瓢虫Propylea japonica (Thunberg)对棉蚜Aphis gossypii Glover的捕食行为及影响的因素。结果表明：龟纹瓢虫对棉蚜的捕食行为依棉蚜的密度变化而逐渐转变;它在棉蚜密度高时,搜索活动下降;而在棉蚜密度低时,则搜索活动增加。产生这种行为是由于肠胃量与棉蚜遭遇率变化的综合作用结果。因此,将瓢蚜比调控在一定水平上,可以更有效地发挥以瓢治蚜的生物防治作用。     

棉蚜及其捕食性天敌时空生态位研究

研究结果表明,棉蚜的时间生态位宽度较小而空间生态位宽度较大,说明棉蚜种群的发生有高峰期明显和全株为害的特点．棉蚜的时动空间生态位宽度与种群密度无相关性,说明棉蚜的为害较复杂．捕食性天敌中草间小黑蛛和龟纹瓢虫的时空生态位宽度较大,说明它们发生期较长、分布范围较广．八斑球腹蛛和龟纹瓢虫与棉蚜的时间生态位重叠度较大,八斑球腹蛛和草间小黑蛛与棉蚜的空间生态位重量度较大．与棉蚜的时间×空间生态位重叠度,八斑球腹蛛＞龟纹瓢虫＞草间小黑蛛＞其它天敌合计＞三色长蝽＞三突花蛛＞小花蝽,这一结果同棉蚜与捕食性天敌数量的关联度大小排序相一致,表明捕食性天敌与棉蚜的时间同步和空间同线性与天敌的捕食作用密切相关．     

人工饲料对龟纹瓢虫捕食功能的影响

研究不同成分的人工饲料对龟纹瓢虫Propylaea japonica(Thunberg)捕食功能的影响。结果表明:不同成分的人工饲料对龟纹瓢虫捕食棉蚜的功能反应类型没有影响,与对照组瓢虫一样均符合HollingⅡ型模型;添加蔗糖的饲料2组的a’/Th(瞬间攻击率/处理时间)要高于其他人工饲料组,表明其对棉蚜的捕食效应较强;各人工饲料组喂养的龟纹瓢虫在捕食功能上要明显劣于野生型龟纹瓢虫。     

转Bt基因棉花对烟粉虱天敌昆虫龟纹瓢虫的影响

在实验室控制条件下,以转Bt基因棉花GK12、33B、SGK321上的烟粉虱为食料饲养龟纹瓢虫,研究转Bt基因棉花上的烟粉虱对龟纹瓢虫生长发育及捕食的影响,同时利用Y型嗅觉仪,观察龟纹瓢虫对来自不同类型棉花的棉叶及其烟粉虱的嗅觉反应和视觉反应。结果表明,转Bt基因棉花和对应的常规棉亲本上的烟粉虱对龟纹瓢虫的发育历期和存活率没有明显的影响。龟纹瓢虫对棉花叶片、烟粉虱若虫、蜜露、蜕等4种物质的视觉反应之间没有明显的差异。对4种嗅源物质的嗅觉选择性的大小依次为：烟粉虱若虫＞蜕＞棉花＞蜜露;在两类不同的棉花之间,转基因棉花和常规棉,龟纹瓢虫对GK12、33B、SGK321等三种转基因棉花上的烟粉虱若虫的嗅觉选择性明显较对应的常规棉亲本SM3、33、SY321上的烟粉虱若虫小;对烟粉虱若虫的蜕,两种转单价基因棉花GK12、33B较对应的常规棉亲本上的小,而转双价基因的棉花SGK321上与对应的常规棉之间没有明显的差异。烟粉虱密度大于200头.皿_-1时,龟纹瓢虫捕食转基因棉花上烟粉虱的数量大于对应的常规棉花亲本,但烟粉虱密度小于200头.皿_-1时,龟纹瓢虫捕食转基因棉花上烟粉虱的数量小于对应的常规棉花亲本。龟纹瓢虫对烟粉虱的捕食符合HollingⅡ型反应。龟纹瓢虫取食转基因棉花上的烟粉虱的理论极限值、瞬间攻击率均大于常规棉花。     

棉田动物群落动态及天敌与害虫种群之间的关系

通过对棉田动物群落动态及天敌与害虫种群之间关系的系统研究,得出：l）棉田生物多样性指数越大,群落稳定性越高;2）龟纹瓢虫与棉蚜种群数量之间极相关,草间小黑株与棉蚜种群之间有相关关系,棉蚜及龟纹瓢虫种群增长为指数增长;3）棉蚜及其多种天敌在水平分布上均为聚集格局;4）棉蚜、龟纹瓢虫及草间小黑蛛在垂直分布上均为聚集格局,龟纹瓢虫对棉蚜聚集场所具有追随跟踪攻击作用．     

Effect of cotton aphids feeding on transgenic cotton varieties on the behavior of Propylaea japonica

本文以GK12、33B和SGK3213种转基因棉和对应的3种常规棉泗棉3号、33及石远321为材料,通过室内测定,研究了取食转基因棉的棉蚜Aphis gossypii Glover对龟纹瓢虫Propylaea japonica Thunberg1～4龄幼虫功能反应的影响.结果指出,龟纹瓢虫对来自转基因棉田蚜虫的捕食量大多高于常规棉田,且捕食量随猎物密度的增加而增大.在1、2龄幼虫期,龟纹瓢虫取食转双价基因棉田蚜虫的数量多高于取食转单价基因棉田的蚜虫数量,但是在3、4龄幼虫时,龟纹瓢虫取食转双价棉田蚜虫的数量多低于取食转单价棉田的蚜虫数量.龟纹瓢虫对来自转基因棉田棉蚜的捕食功能反应符合HollingⅡ型.龟纹瓢虫1龄幼虫取食GK12和SGK321 2个转基因棉田蚜虫的最大日捕食量大于对照,处理时间短于对照;龟纹瓢虫P.japonica 2、3龄幼虫取食33B和SGK321 2个转基因棉田蚜虫A.gossypii的日最大捕食量大于对照,处理时间短于对照;4龄时取食转基因棉田蚜虫的数量都大于对照,处理时间均短于对照,其中取食转双价基因棉SGK321棉田蚜虫的日最大捕食量小于取食单价棉田蚜虫的日最大捕食量.     

十一星瓢虫对枸杞棉蚜的捕食作用研究

十一星瓢虫Coccinella undecimpunctata Linnaeus是青海省柴达木地区的一种重要捕食性天敌。为明确其对枸杞棉蚜Aphis gossypii Glover和枸杞木虱Poratrioza sinica Yang et Li.两种主要枸杞害虫的嗜好性,开展了捕食选择性试验,发现当两种害虫共存时,瓢虫成虫更喜食棉蚜。为进一步探究十一星瓢虫对枸杞棉蚜的捕食能力,测定了瓢虫各龄幼虫和成虫在不同棉蚜密度下的捕食量、寻找效应以及种内干扰、自身密度对捕食作用的影响。结果表明：十一星瓢虫各虫态对棉蚜的捕食功能反应均符合Holling-Ⅱ功能反应模型,种内干扰、自身密度对捕食量的影响分别符合Hassell干扰效应模型和Watt模型。十一星瓢虫1~4龄幼虫及成虫对枸杞棉蚜的日最大理论捕食量分别为18.94、44.29、81.57、145.27和126.48头;在一定空间、相同瓢蚜比条件下,瓢虫同一虫态个体间存在种内干扰效应,以1龄幼虫受干扰最大,干扰常数为1.1803。此外,瓢虫自身密度对其捕食作用产生一定影响,以4龄幼虫和成虫尤甚,竞争参数分别为0.7948、0.6848。本研究可为今后更高效地利用青海高原本地十一星瓢虫资源提供理论依据。     

取食不同品种棉花的棉蚜对龟纹瓢虫功能反应的影响

本文以GK12、33B和SGK3213种转基因棉和对应的3种常规棉泗棉3号、33及石远321为材料,通过室内测定,研究了取食转基因棉的棉蚜却h／sgossypiiGlover对龟纹瓢虫Propylaea japonica Thunberg1—4龄幼虫功能反应的影响。结果指出,龟纹瓢虫对来自转基因棉田蚜虫的捕食量大多高于常规棉田,且捕食量随猎物密度的增加而增大。在1、2龄幼虫期,龟纹瓢虫取食转双价基因棉田蚜虫的数量多高于取食转单价基因棉田的蚜虫数量,但是在3、4龄幼虫时,龟纹瓢虫取食转双价棉田蚜虫的数量多低于取食转单价棉田的蚜虫数量。龟纹瓢虫对来自转基因棉田棉蚜的捕食功能反应符合HollingII型。龟纹瓢虫1龄幼虫取食GK12和SGK3212个转基因棉田蚜虫的最大日捕食量大于对照,处理时间短于对照;龟纹瓢虫P．japonica2、3龄幼虫取食33B和SGK3212个转基因棉田蚜虫A．gossypii的日最大捕食量大于对照,处理时间短于对照;4龄时取食转基因棉田蚜虫的数量都大于对照,处理时间均短于对照,其中取食转双价基因棉SGK321棉田蚜虫的日最大捕食量小于取食单伊棉田蚜虫的日最大捕食量。     

不同饥饿程度的龟纹瓢虫成虫对烟蚜的捕食作用

试验研究了不同饥饿程度的龟纹瓢虫雌、雄成虫对烟蚜的捕食作用。结果表明,不同饥饿程度的龟纹瓢虫雌、雄成虫对烟蚜捕食的功能反应均为Ｈｏｌｌｉｎｇ Ⅱ型,雌成虫的瞬间攻击率ａ大于雄成虫;不同饥饿程度的龟纹瓢虫雌、雄成虫在２４ｈ内对烟蚜的捕食量差异不显著;雌成虫捕食量大于雄成虫;饥饿时间愈长,烟蚜密度愈大,雌雄成虫间捕食量差异愈显著;未饥饿的龟纹瓢虫雌、雄成虫在２４ｈ内对烟蚜的捕食行为集中在６：００～１８     

两种瓢虫对刺槐蚜的捕食作用

在实验室条件下研究了龟纹瓢虫成虫和异色瓢虫成虫对不同密度刺槐蚜的捕食功能反应,符合HollingⅡ 型功能反应模型,其模型分别为:Na=0.4050/1+0.0073N和Na=0.4227N/1+0.0046N,x2值均小于X20. 05=9.49,最大捕食量分别为55.6头和90.9头.圆盘方程理论值与实测值相符.随着瓢虫密度的增加,单个瓢虫捕食率下降,龟纹瓢虫和异色瓢虫自身密度的干扰效应模型分别为:E=0.208P-0.235,E=0.236P-0.324.     

Interactive effects of elevated CO2 and cotton cultivar on tri-trophic interaction of Gossypium hirsutum, Aphis gossyppii, and Propylaea japonica

Information on the effects of enriched CO2 on both the chemical composition of plants and the consequences of such changes for performance of a herbivore and its predator is an important first step in understanding the responses of plants and insects to global environmental change. We examined interactions across three trophic levels, cotton, Gossypium hirsutum, an aphid herbivore, Aphis gossypii Glover, and a coccinellid predator, Propylaea japonica (Thunberg), as affected by elevated CO2 concentrations and crop cultivars. Plant carbon:nitrogen (C:N) ratios, condensed tannin, and gossypol content were significantly higher, and nitrogen content was significantly lower in plants exposed to elevated CO2 levels compared with that in plants exposed to ambient CO2. Cotton aphid survivorship significantly increased and free fatty acid content decreased with increased CO2 concentrations. No significant differences in survival and lifetime fecundity of P. japonica were observed between cultivars and CO2 concentration treatments. However, stage-specific larval durations of the lady beetle were significantly longer when fed aphids from elevated CO2 concentrations. Our results indicate that high gossypol in the cotton host plant had an antibiotic effect on A. gossypii and produced a positive effect on growth and development of P. japonica at the third trophic level. However, elevated CO2 concentrations showed a negative effect on P. japonica. We speculate that A. gossypii may become a more serious pest under an environment with elevated CO2 concentrations because of increased survivorship of aphid and longer development time of lady beetle.     

棉花苗期棉蚜的二项式抽样设计及其精度分析

基于棉花苗期棉蚜（Ａｐｈｉｓ ｇｏｓｓｙｐｉｉ）的２４组调查数据,利用每样方虫口不超过数阈值Ｔ（为０,１,２,…,９,１０,１５,２０,３０）头蚜虫的植株比例（ＰＴ）与种群密度（ｍ,头／株）的关系,拟合经验关系式１ｎ（ｍ）＝α＋ｂ１ｎ〔－１ｎ（ＰＴ）〕设计二项式抽样。通过对不同数阈值Ｔ的决定系数（ｒ＾２）、估计方差（Ｖａｒ（ｍ））和抽样精度（ｄ估计）等进行综合分析,结果表明该蚜虫在数阈值Ｔ为１５时     

Effect of cotton cultivar on development and reproduction of Aphis gossypii (Homoptera: Aphididae) and its predator Propylaea japonica (Coleoptera: Coccinellidae)

The effects of three cotton cultivars with low ('ZMZ13'), medium ('HZ401'), and high ('M9101') gossypol contents on the development, reproduction, and survival of Aphis gossypii Glover and its predator Propylaea japonica (Thunberg) were investigated. Developmental duration and immature survivorship did not vary between aphids on the three cultivars, whereas A. gossypii feeding on M9101 (high gossypol cultivar) displayed significantly shorter adult longevity and lower fecundity than aphids fed on 'ZMS13' and 'HZ401'. Free fatty acid content in cotton aphids reared on 'M9101' was greater than in those reared on 'HZ401' and 'ZMS13'. No significant differences in survival and lifetime fecundity of P. japonica were observed between P. japonica fed cotton aphids reared on the three different cultivars. P. japonica fed aphids from 'M9101' showed a significantly shorter developmental period and greater adult weight than those fed aphids from the other two cultivars. The decreased larval developmental duration and increased adult weight of P. japonica fed cotton aphids reared on the high gossypol-containing cultivar might have been caused by the high fatty acid content of the prey aphids. Our results indicate that high gossypol in host cotton had an antibiotic effect on A. gossypii and showed a positive effect on growth and development of P. japonica at the third trophic level. This suggests compatibility between one form of host plant resistance and biological control by predators. The allelochemical contents should be taken into account in integrated pest management for their effects on both herbivores and entomophagous insects.     

Within-plant distribution of cotton aphids, Aphis gossypii Glover (Hemiptera: Aphididae), in Bt and non-Bt cotton fields

Knowledge of the vertical and horizontal distribution of Aphis gossypii Glover (Hemiptera: Aphididae) on genetically modified cotton plants over time could help optimize decision-making in integrated cotton aphid management programs. Therefore, the aim of the present study was to determine the vertical and horizontal distribution of A. gossypii in non-transgenic Bt cotton and transgenic Bt-cotton over time during two cotton seasons by examining plants throughout the seasons. There was no significant interaction between years and cotton cultivar treatments for apterous or alate aphids. Considering year-to-year data, analyses on season-long averages of apterous or alate aphids showed that aphid densities per plant did not differ among years. The number of apterous aphids found per plant for the Bt transgenic cultivar (2427 apterous aphids per plant) was lower than for its isoline (3335 apterous aphids per plant). The number of alate aphids found per plant on the Bt transgenic cultivar (12.28 alate aphids per plant) was lower than for the isoline (140.56 alate aphids per plant). With regard to the vertical distribution of apterous aphids or alate aphids, there were interactions between cotton cultivar, plant age and plant region. We conclude that in comparison to non-Bt cotton (DP 4049), Bt cotton (DP 404 BG (Bollgard)) has significant effects on the vertical, horizontal, spatial and temporal distribution patterns of A. gossypii, showing changes in its distribution behaviour inside the plant as the cotton crop develops. The results of our study are relevant for understanding the vertical and horizontal distribution of A. gossypii on Bt cotton cultivar (DP 404 BG (Bollgard)) and on its isoline (DP 4049), and could be useful in decision-making, implementing controls and determining the timing of population peaks of this insect.     

棉蚜寄主专化型及其形成的行为机理

通过生活在甜瓜和棉花上的棉蚜Aphisgossypii Glover的行为,研究棉蚜的寄主专化型及其形成的行为机理。生物学观察显示： 两类棉蚜在寄主植物相互交换以后,定居数显著减少,棉花蚜型棉蚜的繁殖系数及若虫存活率显著下降,说明棉蚜存在甜瓜蚜型和棉花蚜型两种寄主专化型。通过刺探电位技术研究棉蚜的取食行为,以探索其寄主专化型形成的行为机理。结果表明： 甜瓜蚜型棉蚜在棉花上的取食行为容易被中断,但其口针定位韧皮部的能力并没有显著削弱;而棉花蚜型棉蚜在甜瓜上的取食行为受到更大的影响,口针无法顺利定位至韧皮部,并在2 h内根本无法在筛管内取食。生物学观察和EPG取食行为分析都显示： 与甜瓜蚜型棉蚜相比,棉花蚜型棉蚜对寄主的要求更严格-寄主专化程度更高,对寄主的利用率更高。     

Genetic diversity of the cotton aphid Aphis gossypii in the unstable environment of a cotton growing area

1 Spatial and temporal habitat heterogeneity represented by annual crops is a major factor influencing population dynamics of phytophagous insect pests such as the cotton aphid Aphis gossypii Glover. We studied the effects of instability of the cotton agroecosystem resulting from the temporary availability of the plant resource and the repeated use of insecticides on the genetic variability of the cotton aphids.
2 Samples of A. gossypii were collected in cotton plots, treated or not with insecticides and from vegetable crops (Malvaceae, Cucurbitaceae and Solanaceae) within the cotton growing area of northern Cameroon. The genetic structure of the samples was assessed using eight microsatellite markers. Insecticide resistance was estimated through the detection of two mutations in the ace -1 gene that are associated with insensitivity of acetylcholinesterase to carbamate and organophosphate insecticides.
3 The results obtained show that both host plants and insecticides act in genetic structuring of A. gossypii . Ninety-three percent of aphids collected on cotton were characterized by the same microsatellite multilocus genotype, Burk1 , which also displays the insecticide resistant alleles.
4 During the dry season, the cotton crop season after, the genotype Burk1 was principally found on two other malvaceous cultivated plants, rosella and okra, acting as suitable reservoir plants. The ability of the cotton aphid to move among asynchronous suitable habitats in response to changes in resource availability enables the pest to exploit unstable cropping systems. An understanding of the cotton aphid life system may aid to improve strategies for integrated resistance management.     

有机农业棉田中棉蚜及其捕食性天敌的种群动态

采用定期目测棉叶上的棉蚜数量,用扫网法同步估测天敌种群数量,对有机农业棉田和常规棉田(对照)中棉蚜及其捕食性天敌的种群动态进行了比较。结果表明,有机棉田和常规棉田中棉蚜及其主要捕食性天敌种群动态差异显著。在2005年6~8月,有机棉田中棉蚜数量是常规棉田的4.17倍(P<0.05)。瓢虫成虫和幼虫的数量分别是常规棉田的3.22倍(P<0.01)和3.70倍(P>0.05);草蛉成虫和幼虫的数量分别是常规棉田的1.33倍(P>0.05)和3.00倍(P<0.05);食蚜蝇的数量是常规棉田的2.89倍(P>0.05),蜘蛛的数量是常规棉田的3.47倍(P<0.05)。因此,建议在有机农业棉花生产中,采用一些植物源杀虫剂辅助控制棉蚜。     

Effects of nitrogen fertilization in cotton crop on Aphis gossypii Glover (Hemiptera: Aphididae) biology

The cotton aphid, Aphis gossypii Glove, is one of the pests of cotton crop and its relation with the host seem to depend on the amount of nitrogen available to the plant. The biology of A. gossypii using different cotton nitrogen fertility regimes was studied under greenhouse conditions, in Dourados, MS. A completely randomized design with nine replications in a factorial scheme (2x4x2)+1 was used. Two nitrogen sources (sulphate of ammonium and urea), four doses of nitrogen (50, 100, 150 and 200 kg ha-1), two different times of nitrogen application and one additional treatment without nitrogen were taken as factors. The nymphal phases, the pre-reproductive, reproductive and pos-reproductive periods, longevity, the life cycle and fecundity of the cotton aphid were evaluated. The doses of nitrogen influenced the cotton aphid biology in both sources and times of application, favoring its development and fecundity.