饥饿对大草蛉雄成虫捕食作用的影响

对不同饥饿程度大草蛉雄成虫捕食作用影响的研究表明,饥饿不能改变大草蛉雄成虫捕食作用功能反应类型,饥饿对捕食量影响不显著;大草蛉雄成虫对麦二叉蚜的捕食量（Ｎａ）随着时间（ｔ）的变化,其模型为Ｎａ＝１００／１＋ｅ＾－０．３０８８－０．０９９６ｔ;大草蛉雄成虫在２４ｈ内的捕食速率（Ｖ）与其时间段（ｘ）的关系为Ｖ＝６．７１１７ｘ＾－０．７９２８;大草蛉雄成虫喜好选择捕食麦二叉蚜的低龄若蚜。     

不同龄期的大草蛉对桃蚜的捕食作用

大草蛉Chrysopa pallens（Rambur）是我国分布较广、捕食能力较强的天敌昆虫。为明确大草蛉对桃蚜Myzus percicae潜在的控制能力,在室内研究了大草蛉不同龄期幼虫和成虫对桃蚜的捕食作用,以及种内干扰对大草蛉捕食的影响。结果表明：25℃恒温条件下,大草蛉成虫和幼虫对桃蚜的捕食功能反应可拟合Holling Ⅱ圆盘方程,在24 h内大草蛉成虫、1龄幼虫、2龄幼虫和3龄幼虫对桃蚜理论最大捕食量分别为370.4头、21.5头、112.4头和217.4头。大草蛉成虫和幼虫对桃蚜的捕食量均随着猎物密度的增加而增加,当桃蚜数量增加到150头后,大草蛉成虫和幼虫捕食量的增加速度明显减缓。成虫及幼虫对桃蚜的搜寻效应随着猎物密度的增加而降低,内干扰作用随着大草蛉虫龄的增加而增强。试验结果表明大草蛉对桃蚜具有较强的控害能力,对研究桃蚜生物防治技术有重要参考价值。     

大草蛉对桃蚜和夹竹桃蚜的捕食作用研究

大草蛉在我国分布广泛,能捕食多种农作物害虫。本试验首先研究了大草蛉一龄幼虫对桃蚜、大草蛉二龄幼虫对桃蚜和夹竹桃蚜的捕食功能反应。三个反应的最大捕食量Namax分别为144．93、303．03和151．51（头）,瞬时攻击率a分别为0．7428、0．8654和0．6644。大草蛉一龄幼虫有较强的种内干扰反应,随着捕食者密度的增加,捕食作用率（E）依次为0．2025、0．1185、0．0866、0．0694和0．0584;对桃蚜的捕食作用率（E）与自身密度（P）的函数关系式为E=0．2025P^-0.7727。在桃蚜和夹竹桃蚜的混合种群中,大草蛉二龄幼虫对桃蚜的选择效应大于夹竹桃蚜。     

不同虫态及虫龄大草蛉与七星瓢虫之间的集团内互作

【目的】为明确新疆棉田棉蚜 Aphis gossypii 捕食性天敌之间的集团内捕食效应及其对蚜虫数量的控制作用。【方法】本研究以优势天敌昆虫大草蛉 Chrysopa pallens 和七星瓢虫 Coccinella septempunctata 为对象,以棉蚜为猎物,在温室中利用盆栽棉花,首先观察了2种天敌昆虫之间各虫态及虫龄配对的19个处理在无蚜植株上共存24 h后的存活数,然后观察了2种天敌昆虫配对处理下棉苗上棉蚜数量随时间的变化趋势。【结果】在无蚜棉株上2种捕食性天敌昆虫共存24 h后的存活结果表明：（1）在发育阶段相同的配对组合中,若是成虫则均存活,若是１龄幼虫则大草蛉存活较多,若是末龄幼虫则七星瓢虫存活较多;（2）在有卵的组配中,除七星瓢虫卵不被大草蛉成虫所捕食外,其他5个组配处理中卵均被捕食;（3）在有蛹的配对组合中,除七星瓢虫蛹被大草蛉末龄幼虫捕食外,其他处理下蛹均不被捕食;（4）在成虫与幼虫的配对组合中,七星瓢虫成虫捕食较多的大草蛉1龄幼虫,但不捕食大草蛉末龄幼虫,而大草蛉成虫与七星瓢虫1龄或末龄幼虫之间不发生捕食;(5）在不同龄期幼虫的配对组合中,大草蛉末龄幼虫捕食七星瓢虫1龄幼虫,而七星瓢虫末龄幼虫捕食大草蛉1龄幼虫。在有蚜植株上2种捕食性天敌共存对棉蚜数量具有不同的控制作用：（1）2种捕食昆虫的幼虫各自单独存在（对照）下,蚜虫密度随时间而降低;（2）大草蛉幼虫与七星瓢虫幼虫或成虫配对处理下,棉蚜密度随时间而增大;（3）大草蛉成虫与七星瓢虫幼虫或成虫配对处理下,棉蚜密度随时间而减小。【结论】研究结果说明,大草蛉与七星瓢虫之间存在集团内捕食,但２种天敌共存对棉蚜的控制作用取决于大草蛉虫态, 若大草蛉为幼虫,可使蚜虫密度增大,若为成虫,则使蚜虫密度减小。     

异色瓢虫成虫对麦二叉蚜的捕食作用模型

通过异色瓢虫雌,雄成虫对麦二叉蚜捕食作用研究,得出：1．异色瓢虫雌、雄成虫对麦二叉蚜捕食作用的功能反应均是HollingⅡ型反应;2．异色瓢虫捕食麦二叉蚜时,同等数量的异色瓢虫雌雄混合的干扰作用大于同一性别成虫间的干扰作用;3．异色瓢虫雌、雄成虫均喜好捕食低龄若蚜．     

广重粉蛉对烟粉虱的捕食作用研究

【目的】广重粉蛉Semidalis aleyrodiformis(Stephens)是烟粉虱Bemisia tabaci(Gennadius)的重要天敌昆虫之一,为了明确其控制潜能,本文研究了广重粉蛉对烟粉虱的捕食作用。【方法】在室内温度(26±1)℃,相对湿度75%±5%,光照周期L∶D=14∶10条件下,对广重粉蛉幼虫捕食烟粉虱各个虫态的捕食作用进行研究。并且评估了广重粉蛉幼虫对烟粉虱卵、广重粉蛉成虫对烟粉虱若虫和伪蛹的捕食功能反应模型,同时,对广重粉蛉成虫捕食烟粉虱卵的干扰反应方程进行了拟合。【结果】广重粉蛉幼虫对烟粉虱的捕食量随着广重粉蛉龄期的增大而增大。广重粉蛉幼虫对烟粉虱卵的功能反应和广重粉蛉成虫对烟粉虱各个虫态的捕食功能反应都呈HollingⅡ型。随着广重粉蛉龄期的增加,广重粉蛉对烟粉虱卵的寻找效率(a)逐渐增加,处置时间(Th)依次缩短;而广重粉蛉成虫对不同龄期烟粉虱的功能反应是随着猎物龄期的增加,寻找效率逐渐降低,处置时间(Th)依次延长。广重粉蛉自身密度方程为E=0.127 9×P-0.317 3,干扰系数为0.317 3。【结论】研究表明,广重粉蛉4龄幼虫和雌成虫对烟粉虱有较好的捕食作用,控害潜力最大。     

亚非草蛉的生物学及其对柑桔潜叶蛾幼虫的捕食效应研究

在实验室条件下,亚非草蛉的平均发育历期为:卵期3.1天,幼虫8.9天,成虫寿命雌虫101.7天、雄虫61.8天,产卵前期8.4天。每雌虫平均产卵量400.3粒。最大产卵量746粒。产卵高峰期为羽化后的16—24天。亚非草蛉对湿度的适应范围较广,但幼虫的死亡率与湿度的关系大。 亚非草蛉幼虫一生捕食柑桔潜叶蛾幼虫数平均为149.1头,其日捕食量随龄期的增大而增加。温度对草蛉幼虫的捕食效应具有显著的影响,在35℃时达到最高的捕食效应,而在15℃以下和40℃以上,则受到明显的限制。湿度对草蛉捕食潜叶蛾幼虫的影响呈Iogistic曲线。草蛉对潜叶蛾幼虫密度的功能反应属HollingⅠ型反应。草蛉幼虫对其自身密度的功能反应可用Watt模型模拟。草蛉对潜叶蛾幼虫的捕食作用率随捕食者个体间的相互干扰作用的增加而下降,两者之间的关系随草蛉幼虫数的增加呈幂函数下降曲线。 田间观察及室内试验结果表明,亚非草蛉是柑桔潜叶蛾的一种重要的捕食性天敌。     

中华通草蛉和大草蛉幼虫对黑刺粉虱若虫的捕食功能反应

【目的】为了研究中华通草蛉Chrysoperla sinica(Tjeder)幼虫和大草蛉Chrysopa pallens(Rambur)幼虫对黑刺粉虱Aleurocan spinfetus(Quaintance)若虫的捕食作用。【方法】在室内(25±1)℃条件下对2种草蛉的捕食功能反应模型进行了评估,并对2种草蛉的3龄幼虫的种内干扰作用和自身密度作用的反应方程进行了拟合。【结果】2种草蛉的捕食功能均属于HollingⅡ反应模型,捕食量均随黑刺粉虱若虫密度的增加而增加。中华通草蛉和大草蛉的自身密度方程分别为E=0.753 0×P~(–0.134 8)和E=0.697 5×P~(–0.164 6),种内干扰作用方程分别为A=2.362 6×P~(–0.231 8)和A=2.429 6×P~(–0.225 6)。【结论】中华通草蛉和大草蛉对黑刺粉虱均具有较好的捕食作用。     

两种草蛉对取食棉花的扶桑绵粉蚧的嗅觉反应（英文）

捕食性的普通草蛉Chrysoperla sp.（carnea group） 和安平草蛉Mallada desjardinsi（Navas）（脉翅目:草蛉科）的寄主-生境定位取决于其觅食行为以及对各阶段释放的植物气味的行为反应.本研究调查了这两种交配的草蛉成虫以及取食棉花的扶桑绵粉蚧Phenacoccus solenopsis的反应,以便了解它们之间的三重营养关系.结果表明：草蛉雄虫和雌虫均能感受到棉花植株释放的绿叶挥发物;植株的各个阶段均可使捕食性昆虫和绵粉蚧定位.在受绵粉蚧为害的棉叶上饱和烃含量高,说明草蛉成虫的反应更为强烈;在植株受为害期和开花期释放捕食性昆虫,可提高田间捕食性昆虫的作用.这些结果提示有效的生物防治取决于捕食性昆虫在植株上的天然定殖能力以及对害虫的吞食能力.     

饥饿对七星瓢虫捕食作用的影响

通过不同饥饿程度七星瓢虫雌、雄成虫对麦二叉蚜捕食作用的研究,得出：①饥饿不能改变七星瓢虫雌、雄成虫捕食作用的功能反应类型;②七星瓢虫雌、雄成虫间在各种饥饿条件下的捕食量差异均不显著;③七星瓢虫雌、雄成虫对麦二叉蚜的捕食量（Ｎａ）随着时间（ｔ）的变化,其模型分别是Ｎａ＝９０／１＋ｅ０．９４５３４－０．１５７４５ｔ和Ｎａ＝９０／１＋ｅ０．８７２８５－０．１２９８５ｔ;④七星瓢虫雌、雄成虫之间在２４ｈ内的捕食速度（Ｖ）差异不显著,其与时间段（ｘ）关系的模型分别为Ｖ＝８．３５５９ｘ－１．２４６０和Ｖ＝４．３４８７ｘ－０．５９６４。     

干扰作用及空间异质性对七星瓢虫成虫捕食作用的影响

通过系统研究,得出：1)七星瓢虫Coccinella septempunctata雌雄成虫在捕食过程中麦秆数越多,环境阻力越大,捕食作用率越低;2)七星瓢虫与异色瓢虫 Harmonis axyridis 捕食过程中的种间干扰作用大于两种瓢虫的种内干扰作用;3)异色瓢虫(♀)种内竞争强度I与瓢虫数P的关系为I=0.0012+1.4072lgP;异色瓢虫(♂)种内竞争强度I与P的关系为I=0.0058+1.3942lgP;七星瓢虫(♀)种内竞争强度I与P的关系为I=-0.0072+0.7234lgP。异色瓢虫(♀)和七星瓢虫(♀)的种间竞争强度I与天敌数量(P)关系的模型为I=0.0539+1.1167 lgP,异色瓢虫(♀)和七星瓢虫(♂)的种间竞争强度I与P的模型为I=0.0018+1.1944lgP。     

七星瓢虫成虫对烟蚜的捕食作用

对七星瓢虫CoccinellaseptempunctataL .成虫对烟蚜Myzuspersicae的捕食作用进行了定量研究。七星瓢虫成虫对烟蚜的功能反应属HollingⅡ型反应 ,拟合的圆盘方程为Na =1 .1 5 76Nt ( 1 +0 .0 0 3 48Nt) ,χ2 检验表明圆盘方程理论值与实测值相符。捕食选择试验表明在烟蚜、烟青虫Helicoverpaassaut(Guenee)卵和 1龄幼虫 3种猎物中 ,七星瓢虫成虫最喜好烟蚜。七星瓢虫成虫对自身密度的功能反应用Watt模型拟合为A =2 90 .0 3P-0 .7584,其捕食作用率与个体间相互干扰作用的关系用Hassell模型拟合为E =0 .8783 7P-0 .1 0 0 94。文中进一步就烟田中七星瓢虫的保护利用进行了讨论。     

Effect of cannibalism and predation on the larval performance of two ladybird beetles

The relative impact of cannibalism and predation on the development and survival of fourth instar larvae was assessed in two species of aphidophagous ladybird beetles, Coccinella septempunctata and Harmonia axyridis. The effect of eating aphids, conspecific larvae or heterospecific larvae on larval performance differed in the two species: aphids were the best food for C. septempunctata and survival of C. septempunctata larvae was significantly lower when offered heterospecific larvae rather than conspecific larvae or aphids as food, indicating that H. axyridis larvae were not suitable food for C. septempunctata. However, as the different foods did not affect the larval performance of H. axyridis, this species appears to be more polyphagous. Both intraguild predation by the aggressive larvae of H. axyridis and the polyphagous food habit of this species may account for its dominance in ladybird assemblages and its displacing other ladybird beetles in several places in the world.     

Survival, development and life tables of two congeneric ladybirds in aphidophagous guilds

Two congeneric aphidophagous ladybirds, Coccinella septempunctata and Coccinella transversalis, were reared on three aphid species, Lipaphis erysimi, Myzus persicae and Aphis nerii, to estimate the effect of prey quality and intra- and interspecific interactions on their survival and development of life stages. Mortality of first instar ladybirds of both species was highest feeding on A. nerii. Preimaginal mortafity was lowest when feeding on L. erysimi （C. septempunctata, 1.6% and C. transversalis, 3.2%）, and highest when feeding on A. nerii （ C. septempunctata, 6.2% and C. transversalis, 8.2%）. Comparatively higher weight and larger size of C. septempunctata along with the lower levels of mortality recorded suggested that it is more likely to have acted as an intraguild predator than C. transversalis. High recorded mortality of C. transversalis is attributed to probable intraguild predation on account of its smaller size. The major sources of mortality were probably cannibalism, intraguild predation and other unknown factors. Lower prey quality increased the incidence of cannibalism and intraguild predation, especially in C. transversalis. The investigation suggests an intrinsic competitive advantage for C. septempunctata over C. transversalis in guilds of three aphid species.     

Intraguild predation of the aphid pathogenic fungus Pandora neoaphidis by the invasive coccinellid Harmonia axyridis

Abstract.  1. The ladybird Harmonia axyridis is an invasive alien species in many countries and is predicted to have a negative impact on native biodiversity. However, little is known on the status of this aphidophage as an intraguild predator of natural enemies of aphids such as insect-pathogenic fungi.
2. The study assessed the predation of the aphid-specific pathogenic fungus Pandora neoaphidis by adult and larval H. axyridis collected from the U.K. (an invasive population) and Japan (a native population) relative to that of the ladybird Coccinella septempunctata (native to the U.K.) and the non-U.K. C. septempunctata subspecies brucki that were either starved or unstarved.
3. Overall, predation of uninfected aphids was greater than infected aphids and, when given a choice, a preference for aphids was shown. However, the extent of this preference was dependent on the species and origin of the coccinellid. Harmonia axyridis (U.K.) consumed the greatest quantity of fungal cadavers and showed little preference for uninfected aphids over infected aphids. In contrast, C. septempunctata rarely consumed infected aphids. Life stage had no direct effects on predation but starved coccinellids consumed more uninfected aphids than infected aphids.
4.  Harmonia axyridis (U.K.) is a stronger intraguild predator of P. neoaphidis cadavers than the native species C. septempunctata and, therefore, may have an impact on the occurrence and persistence of P. neoaphidis . The differences in intraguild predation by H. axyridis collected in the U.K. and those from Japan suggests that individuals that invaded the U.K. could have a different genetic profile to those in its native range.     

Intraguild predation behaviour of ladybirds in semi-field experiments explains invasion success of Harmonia axyridis

Harmonia axyridis has been introduced as a biological control agent in Europe and the USA. Since its introduction, it has established and spread, and it is now regarded as an invasive alien species. It has been suggested that intraguild predation is especially important for the invasion success of H. axyridis. The aim of this study was to compare the intraguild predation behaviour of three ladybird species (Coccinella septempunctata, Adalia bipunctata, and H. axyridis). Predation behaviour was investigated in semi-field experiments on small lime trees (Tilia platyphyllos). Two fourth-instar larvae placed on a tree rarely made contact during 3-hour observations. When placed together on a single leaf in 23%-43% of the observations at least one contact was made. Of those contacts 0%-27% resulted in an attack. Harmonia axyridis attacked mostly heterospecifics, while A. bipunctata and C. septempunctata attacked heterospecifics as often as conspecifics. In comparison with A. bipunctata and C. septempunctata, H. axyridis was the most successful intraguild predator as it won 86% and 44% of heterospecific battles against A. bipunctata and C. septempunctata respectively, whilst A. bipunctata won none of the heterospecific battles and C. septempunctata won only the heterospecific battles against A. bipunctata. Coccinella septempunctata dropped from a leaf earlier and more often than the other two species but was in some cases able to return to the tree, especially under cloudy conditions. The frequency with which a species dropped did not depend on the species the larva was paired with. The results of these semi-field experiments confirm that H. axyridis is a strong intraguild predator as a consequence of its aggressiveness and good defence against predation from heterospecific species. The fact that H. axyridis is such a strong intraguild predator helps to explain its successful establishment as invasive alien species in Europe and the USA.     

Interactions between introduced and native predatory ladybirds (Coleoptera, Coccinellidae): factors influencing the success of species introductions

Abstract.  1. Why some exotic species invade successfully while others do not is poorly understood. This study focuses on the inability of the exotic predatory ladybird Adalia bipunctata (L.) (Coleoptera, Coccinellidae) to establish and spread in Japan. In particular, this study considers the interactions between A. bipunctata and three native Japanese ladybird species, Harmonia axyridis Pallas, Coccinella septempunctata Linn., and Propylea japonica Mulsant.
2. The number of aphids occurring on the host plants declined dramatically over the course of larval development in the presence of H. axyridis or C. septempunctata . In contrast, many aphids remained at the end of the experiment when only A. bipunctata or P. japonica was present.
3. The survivorship of A. bipunctata from second instar to adult was significantly reduced in the presence of H. axyridis , but not in the presence of C. septempunctata or P. japonica . Most deaths were the result of intra-guild predation when H. axyridis or C. septempunctata larvae were present. Larvae of H. axyridis and C. septempunctata suffered very high mortality in this experiment, but survived better when co-occurring with A. bipunctata than when occurring only with conspecifics. In contrast, P. japonica survived better when occurring with conspecifics than with A. bipunctata .
4. The finding that larvae of the exotic species A. bipunctata died at high rates from intra-guild predation by the native Japanese ladybirds H. axyridis and C. septempunctata may bear on the question of why A. bipunctata has not established more successfully in Japan whereas H. axyridis and C. septempunctata have been very successful in establishing themselves in North America.     

Relationships Between Attack and Escape Rates, Cannibalism, and Intraguild Predation in Larvae of Two Predatory Ladybirds

We compared incidences of cannibalism and intraguild (IG) predation (IGP) and quantified attack and escape rates—mechanisms which possibly account for the difference in incidences of these interactions—in laboratory experiments with Harmonia axyridis and Coccinella septempunctata. There was a tendency for H. axyridis to act as an IG predator and C. septempunctata as an IG prey. Cannibalism was also often observed in both species. The incidences of both IGP and cannibalism were different between the species. The average attack rates of C. septempunctata were less than 20%, but those of the more aggressive H. axyridis exceeded 50%. Larvae of both species attacked conspecifics and heterospecifics H. axyridis larvae successfully escaped when attacked by both conspecifics and by heterospecifics, while larvae of C. septempunctata escaped from attacks of conspecifics but not from those of heterospecifics. Thus the aggressive behavior of H. axyridis, in particular, of the third and fourth instars, negatively affects the larval survival of C. septempunctata. It may contribute to the dominance of H. axyridis in ladybird assemblages and its displacement of other ladybird species in several places in the world.     

Dropping behaviour of larvae of aphidophagous ladybirds and its effects on incidence of intraguild predation: interactions between the intraguild prey, Adalia bipunctata (L.) and Coccinella septempunctata (L.), and the intraguild predator, Harmonia axyridis Pallas

Abstract.  1. Two experiments were performed in the laboratory to assess the behaviour of dropping from a host plant as a defence against intraguild predation in aphidophagous ladybird larvae.
2. In the first experiment, encounters were observed on bean plants between fourth instars of the intraguild predator species, Harmonia axyridis , and first instars of two other ladybird species, Adalia bipunctata (L.) and Coccinella septempunctata (L.). The percentages of first instars of the latter two species that dropped from the plant in response to attack differed dramatically, with 47.5% of C. septempunctata first instars dropping vs. 0% of A. bipunctata .
3. In the second experiment, first instars of A. bipunctata or C. septempunctata and a fourth instar of H. axyridis were allowed to forage together on bean plants for 3 h. During this time, 44.3% of C. septempunctata larvae dropped from the plant, but less than 2% of A. bipunctata larvae did so. In contrast, 95.0% of A. bipunctata larvae fell victim to intraguild predation by H. axyridis vs. only 54.5% of C. septempunctata larvae.
4. The significance of dropping behaviour of ladybird larvae as a defence against intraguild predation, and the relationship of dropping behaviour to species-specific habitat affinity of ladybirds, is discussed.