Polymorphism of the harlequin ladybird Harmonia axyridis (Coleoptera, Coccinellidae) Baikal population

The phenotypic composition of the Baikal population of the harlequin ladybird Harmonia axyridis (Pallas, 1773) was analyzed based on the material collected in Irkutsk Province in 2009–2010. Significant microgeographic phenotypic variation was revealed on the Baikal coast and in the city of Irkutsk. The morph axyridis, widespread in Siberia, was dominant (80–90%) but the light-colored morph succinea was also present with high frequencies (43–59%) in some samples. Some individuals possessed an elytral ridge, their frequency in the Baikal population being low (4–6%). An increase in the number of the morph succinea in Irkutsk Province is not related to hybridization between the populations from the Far East and Siberia.     

Mechanisms of prey finding in the aphidophagous ladybird beetle,Harmonia axyridis [Coleoptera: Coccinellidae]

The mechanism of prey finding in adultHarmonia axyridis was investigated by presenting beetles with small gauze or polyethylene bags containing either aphidinfested leaves or healthy leaves alone together with empty control bags. Beetles were attracted to bags by olfactory and visual cues suggesting the presence of aphids, including the odor of aphid-infested leaves, the odor of aphids, the odor of healthy leaves, and the sight of leaves. Particularly effective in prolonging beetles's stay on bags visited was the odor of aphid-infested leaves. It is suggested that adults ofH. axyridis use olfactory and visual cues to detect prey before actual contact occurs. Use of such cues seems more advantageous than random searching, as has been reported in many previous studies of coccinellid foraging.

---

Résumé Le mécanisme de découverte de la proie chez l'adulte d'Harmonia axyridis est étudié en donnant aux Coccinelles de petits sacs en gaze ou en polyéthylène contenant soit des feuilles infestées de pucerons, soit des feuilles saines seules, avec des sacs vides comme témoins. Les coccinelles sont attirées vers les sacs par des indicateurs olfactifs ou visuels suggérant la présence de pucerons, incluant l'odeur des feuilles infestées de pucerons, l'odeur des pucerons, l'odeur des feuilles saines et la vue des feuilles. L'odeur des feuilles infestées de pucerons est particulièrement efficace en prolongeant le séjour des Coccinelles sur le sac visité. Il est suggéré que les adultes d'H. axyridis utilisent des indicateurs olfactifs et visuels pour détecter leur proie avant que s'établisse le véritable contact. L'emploi de tels indicateurs semble plus avantageux que la recherche au hasard, comme cela a été indiqué dans de nombreuses études antérieures sur la quête alimentaire des Coccinelles.

     

Record of the invasive alien ladybird Harmonia axyridis (Coleoptera, Coccinellidae) from Kenya

The biological control agent and alien invasive ladybird Harmonia axyridis (Pallas, 1773) was recorded for the first time in Kenya, and in equatorial Africa, in 2010.     

Sex-dependent effects of sibling cannibalism on life history traits of the ladybird beetle Harmonia axyridis (Coleoptera: Coccinellidae)

To investigate the sex-dependent effects of sibling cannibalism on variations in life history traits, I analysed body size, weight and instar interval in relation to the occurrence of sibling cannibalism in the ladybird beetle Harmonia axyridis. Sibling cannibalism at the time of hatching significantly affected the body size and weight of adults. There was a 2.32% and 1.05% increase in the body size of males and females, respectively, and a 3.55% increase and a 2.30% decrease in their respective body weights. Sibling cannibalism also significantly shortened the total and larval instar intervals, by 4.24% in males and by 1.22% in females, mainly due to shortening of the first instar. These results suggest that the effects of sibling cannibalism on life history traits are sex-differentiated and are greater in males than in females. A simulation of aphid density indicated that shortening the instar interval affected larval survival; the aphid density when the larvae completed development was 39.71% and 10.52% larger for cannibalistic males and females, respectively, than for non-cannibals. These results suggest that sibling cannibalism promotes more rapid development and larger adult size, although the effect was more pronounced in males than in females. Faster development may be adaptive for resource tracking, and the large adult size may increase fecundity in females and mating success in males through female mate choice, both resulting in an increase in the fitness of cannibals.  © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 76 , 349–360.     

Population field studies on the aphidophagous ladybird beetle Harmonia axyridis (Coleoptera: Coccinellidae): resource tracking and population characteristics

To clarify functional and numerical responses to temporal and spatial variations of resources (resource tracking), and the population characteristics of the ladybird beetle Harmonia axyridis, I analyzed the results of a 3-year field observation at 24 sites (seven plant species) on eight species of aphids. The seasonal changes in the number of beetles estimated by the Jolly–Seber method were significantly correlated with those of aphids in the total area. The estimated values of population parameters suggested frequent immigration and emigration of the H. axyridis population, although reproductive rates between spring and summer were rather stable all 3 years (1.87–3.49). The staying time and the daily number of adults and eggs at each site were influenced not only by a single factor but also by interactions among time and quantity and quality of the prey. The adult movement showed two patterns, which corresponded with the movement within and between the subpopulations when an assemblage of H. axyridis occurring on the plants of the same species or genus was regarded as a subpopulation. Adult movement intensely occurred within a subpopulation, although the beetles moving between subpopulations had a significantly greater chance to reach the habitat with a high aphid density. The habitats of H. axyridis could be categorized into a suitable habitat for survival and reproduction and a temporal refuge. The results obtained here suggest that H. axyridis, with high ability of prey searching and reproduction, maintains a stable population in heterogeneous and temporal habitats by its resource tracking mechanisms. Received: March 8, 1999 / Accepted: April 25, 2000     

Geographic variation of color polymorphism in two sibling ladybird species,Harmonia yedoensis and H. axyridis (Coleoptera: Coccinellidae)

Geographical variation of elytra color pattern in two sibling ladybird species, Harmonia yedoensis and H. axyridis (Coleoptera: Coccinellidae), was examined. The two species are distributed sympatrically in central Japan; however, only H. yedoensis and H. axyridis occur in the Ryukyu Islands (southern Japan) and Hokkaido island (northern Japan), respectively. The frequency of elytra color patterns was significantly different between the two species in all sympatric locations and our results were inconsistent with the classical theory on Müllerian mimicry. The most dominant pattern of H. axyridis was the least dominant of H. yedoensis in all sympatric populations. Furthermore, the frequency of the non‐melanic form (red ground color with or without black spots) increased towards the south in H. yedoensis. This tendency was in contrast to the known geographical cline in H. axyridis in which the melanic form (black ground color with red spots) was gradually displaced with the non‐melanic form northwards in the Japanese archipelago. We discuss possible selective factors including predator avoidance, thermal adaptation and reproductive character displacement, all of which might contribute to the maintenance of the color polymorphism in the two Harmonia species.     

Honeydew volatile emission acts as a kairomonal message for the Asian lady beetle Harmonia axyridis (Coleoptera: Coccinellidae)

Abstract The Asian lady beetle Harmonia axyridis Pallas is considered as an invasive species in most territories where it has been introduced. Because aphid honeydew acts as an attractant for many aphid predators and parasitoids, the objectives of this work were to collect and identify the volatile compounds released from the aphid excretory product to evaluate how these semiochemicals could affect the H. axyridis foraging behavior. Twelve volatile chemicals were identified from the Megoura viciae Buckton honeydew including four alcohols, three ketones, three aldehydes, a pyrazine and a monoterpene. The volatiles 3‐methyl‐1‐butanol and 3‐methyl‐butanal were highlighted as the two most abundant semiochemicals released from the M. viciae honeydew. Vicia faba L. plants treated with crude honeydew attracted more than 80% of the tested individuals with 40% of attracted beetles located on the plant. Four volatile compounds (3‐hydroxy‐2‐butanone, 3‐methyl‐butanal, 3‐methyl‐1‐butanol and limonene) were also highlighted to attract more than 75% of the coccinellids toward the odor source and to locate about 35% of them on the plants. Limonene was the most efficient attractant since 89% of the H. axyridis responded to this odor. The use of the identified semiochemicals as well as the composition of an artificial honeydew could certainly be helpful to control the dispersal of the Asian lady beetle H. axyridis.     

Weak photoperiodic response facilitates the biological invasion of the harlequin ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)

Photoperiodic regulation of reproductive diapause in two invasive and two native populations of Harmonia axyridis and in one native population of Harmonia yedoensis was investigated in laboratory at 20°C, five photoperiods (day length of 10, 12, 14, 16 and 18 h) and two diets: (i) eggs of the Angoumois grain moth Sitotroga cerealella and (ii) the green peach aphid, Myzus persicae. Laboratory strains originated from native populations of H. axyridis from Irkutsk province of Siberia and H. yedoensis from South Korea showed a strong photoperiodic response: under short photoperiods (10–14 h and 10–12 h for H. axyridis and H. yedoensis, correspondingly), all females which fed on eggs and most of those fed on aphids did not start to lay eggs during 40 days after emergence, while under long photoperiods, all females fed on aphids and most of those fed on eggs oviposited. The photoperiodic response of H. axyridis from South Korea was less strong: on the both diets, the range of the photoperiodic response (the difference in the proportion of ovipositing females between the treatments with long and short days) was ca 40%. In the European (Czech Republic) and in the Caucasian (Sochi region, Russia) invasive populations of H. axyridis, the photoperiodic response was very weak: the proportion of females that started oviposition (when fed on aphids) or at least reproductive maturation (when fed on eggs) during 40 days after emergence was close to 100%, independently of the photoperiodic conditions. Obviously, instead of a rapid micro‐evolutionary adaptation of the critical day length to a new climate, the invasive populations of the harlequin ladybird decrease their dependence on photoperiod and thus the weak photoperiodic response of SE Asian population of H. axyridis can be considered as a pre‐adaptation further developed during the invasion.     

异色瓢虫不同色斑型成虫的耐寒性研究

【目的】研究异色瓢虫Harmonia axyridi不同色斑型成虫的耐寒能力,以明确其色斑型比例所呈现的季节性变化的适应意义。【方法】本文测定了异色瓢虫实验种群和自然种群不同色斑型成虫的过冷却点(Supercooling point,SCP)及低温存活率。【结果】同一发育温度下异色瓢虫实验种群不同色斑型成虫的SCP和低温存活率均没有显著性差异(P>0.05),但是低温暴露中饲养在25℃下成虫的存活率下降更为剧烈。异色瓢虫自然种群黑底型与黄底型成虫的SCP呈现出明显的季节性变化,其SCP在7月份最高,分别为﹣8.2℃和﹣7.5℃;在1月份达到最低,分别为﹣16.8℃和﹣18.2℃。越冬开始(11月)黑底型成虫的SCP低于黄底型成虫的,整个越冬期间黄底型成虫的SCP一直低于黑底型成虫的,但是异色瓢虫黑底型与黄底型越冬成虫的低温存活率却没有显著性差异(P>0.05)。【结论】越冬期间异色瓢虫黄底型成虫的SCP低于黑底型的,这样可以通过体液过冷却的方式来避免结冰造成的伤害,以增强其越冬种群的耐寒能力,这也可能是越冬期间异色瓢虫黄底型成虫数量显著上升的一个原因。     

The influence of aphids on the behaviour of adults of the ladybird beetle,Harmonia axyridis (Col.: Coccinellidae)

The mechanism of prey finding by adultHarmonia axyridis (Pallas) (Coleoptera, Coccinellidae) was investigated in the laboratory by offering beetles small gauze or polyethylene bags containing either aphid-infested leaves or uninfested leaves along with empty control bags. The beetles were attracted to bags containing aphid-infested leaves. It is suggested that adults ofH. axyridis use olfactory and visual cues to detect prey. Mate-searching by males and the mating receptivity of females were enhanced in the presence of an abundance of aphids. The presence of aphids, perceived by the sensory organs of the beetles, possibly influence behaviour other than prey-searching.     

Differences in biological and behavioural characteristics of Harmonia axyridis (Coleoptera: Coccinellidae) according to colour patterns of elytra

Samples of overwintering populations of Harmonia axyridis were classified into five colour patterns, succinea 1, succinea 2, conspicua, spectabilis and axyridis. Generally, the succinea 1 colour pattern was dominant at six collecting sites in Daejon and Chungnam provinces of Korea and their occurrence proportion was over 50%. Non‐melanic forms such as succinea 1 and 2 were noted in about 90% of collected individuals. On the other hand, conspicua and spectabilis as melanic forms were dominant in the laboratory. One hypothesis is that the difference between field and laboratory populations is related to non‐random mating and environmental conditions. Practically, in mate‐choice experiments, most colour pattern ladybirds seemed to mate with the melanic form, especially the conspicua form. The body size (length) of H. axyridis in colour patterns was slightly different, but in females, there was no significant difference among colour patterns. However, both lengths of males were significantly different among colour patterns. In reproductive ability (fecundity), there was no difference among colour patterns.     

The potential impacts of the arrival of the harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), in Britain

Abstract.  1. The harlequin ladybird, Harmonia axyridis , has recently arrived in Britain.
2. This species has been introduced from Asia into many parts of the world for biological control purposes.
3. In many parts of North America it has become the predominant aphidophagous coccinellid in less than 20 years, and in north-western Europe it is spreading and increasing in number rapidly.
4. Since establishment in North America and continental Europe, reports of its effectiveness as a biological control agent of aphids and coccids have been accompanied by accounts of negative effects on other aphidophagous species and humans.
5. Here the potential impacts of the arrival of the harlequin ladybird in Britain are assessed.     

异色瓢虫卵黄蛋白单克隆抗体的制备及鉴定

【目的】为了能准确地追踪异色瓢虫Harmonia axyridis (Pallas)卵黄原蛋白（vitellogenin, Vg）的合成、转运途径和吸收方式,以及卵黄蛋白（vitellin, Vn）在卵母细胞内的积累及分布情况,本研究对异色瓢虫的Vn进行了单克隆抗体（monoclonal antibody, McAb）的制备。【方法】以异色瓢虫Vn免疫BLAB/C小鼠,应用杂交瘤技术,经过3次亚克隆筛选,制备能稳定分泌抗Vn的单克隆抗体。【结果】实验获得4株能够稳定分泌抗异色瓢虫Vn的单克隆抗体,即5E2, 5E11, 1E9和5H8。其中1E9, 5E11和5E2亚型均为IgG1,5H8亚型为IgM。Western blot免疫印迹分析显示,4株单克隆抗体可以特异性地识别Vn,而与雄虫血淋巴无反应。其中,5E2和1E9可以与异色瓢虫抗原的4个亚基发生较强的免疫反应,结合腹水制备前上清效价检测结果最终选取5E2制备单克隆抗体。5E2单克隆抗体的效价为1∶81 000,SDS-PAGE分析显示5E2重链和轻链的分子量分别为50和27 kD。【结论】本实验成功制备出一株能够稳定分泌抗异色瓢虫Vn的单克隆抗体,为建立酶联免疫吸附试验（ELISA）方法测定其动态变化奠定了基础。     

Individual variation in two host plants of the ladybird beetle,Epilachna pustulosa (Coleoptera: Coccinellidae)

Individual variation in two species of host plants (thistle,Cirsium kamtschaticum, and blue cohosh,Caulophyllum robustum) of the herbivorous ladybird beetleEpilachna pustulosa was examined under laboratory conditions for their acceptability to adult beetles as a food resource, for adult preference and for larval performance. When clones of these plants were subjected to non-choice tests using posthibernating female beetles, there was found to be significant intraspecific variation among clones in terms of their acceptability, but interspecific variation was not detected. Significant intraspecific as well as interspecific variation were frequently detected in the two host plants when clones of these plants were subjected to choice tests using posthibernating female beetles; the magnitude of interspecific plant variation for beetle preference is not necessarily larger than that of intraspecific plant variation. Individual variation across plant species with respect to beetle larval performance was also significant. A positive correlation between adult preference and larval performance is suggested across the two taxonomically remote host plant species, thistle and blue cohosh, although this needs further investigation.     

Isolation and characterization of microsatellites in the harlequin ladybird, Harmonia axyridis (Coleoptera, Coccinellidae), and cross-species amplification within the family Coccinellidae

A total of 18 microsatellite DNA loci were isolated and characterized from the harlequin ladybird, Harmonia axyridis (Coleoptera: Coccinellidae). We optimized a multiplex panel consisting of two polymerase chain reactions, allowing the genotyping of all loci. The number of alleles and heterozygosity observed at each locus ranged from 1 to 12 and from 0 to 100%, respectively. After Bonferroni correction for multiple tests, none of the loci deviated significantly from Hardy-Weinberg equilibrium and there was no indication of significant linkage disequilibrium among pairs of loci. Successful cross-species amplification was obtained for only three of the seven tested species of Coccinellidae.     

The invasion history,distribution and colour pattern forms of the harlequin ladybird beetle Harmonia axyridis (Pall.) (Coleoptera,Coccinellidae) in Slovakia,Central Europe

The harlequin ladybird beetle Harmonia axyridis (Coleoptera, Coccinellidae) has invaded and established in Slovakia. Following unintentional introduction in 2008, the spread of the alien coccinellid was very fast. By the end of 2009, it was recorded across the whole country, and by the end of 2012 it was widely distributed and common in various habitats, particularly gardens, orchards and urban areas, where it was most frequent on trees. The rate of eastward spread was approximately 200 km year^-1, similar to the overall rate of spread in Europe. Between 2008 and 2012, the coccinellid was recorded in a total of 153 localities, in altitudes ranging from 98 to 1,250 m. Most records of this species were made in lowlands, hilly areas and valleys separating mountain ridges. However, it was only rarely documented in areas above 700 m a.s.l. The non-melanic colour form (f. succinea) was dominant along a longitudinal transect including eight urban areas across Slovakia, with the frequency of melanic forms (f. spectabilis and f. conspicua together) between 6.3 and 19.2% and a median equal to 10.5%. The invasion history and distribution of H. axyridis in Slovakia are discussed with regard to the time sequence of records, rate of spread, altitudinal distribution, anthropogenic dispersal, effective recording, proportion of melanic forms and other relevant aspects associated with the spread of this successful invader.     

异色瓢虫成虫耐寒能力的季节性变化

为研究异色瓢虫Harmonia axyridis自然种群耐寒能力的季节性变化,测定了其过冷却点、体内含水量及总脂肪含量和低温存活力。结果表明：异色瓢虫成虫低温存活力呈现出明显的季节性变化,越冬前成虫的耐寒性显著强于夏季成虫和越冬后成虫。冷驯化（5℃, 5 d）可以显著提高夏季成虫的低温存活力。雌雄成虫过冷却点和体内含水量随气温的降低而降低,升高而升高。过冷却点7月份最高,分别为−7.6℃和−8.0℃;越冬中期（2008-01-15）最低,分别为−18.1℃ 和−16.9℃。雌雄成虫体内含水量9月份最高,分别为66.87%和68.01%,10月份显著降低,越冬后期（2008-02-19）最低,分别为52.94%和51.53%。越冬期间过冷却点和体内含水量显著低于其他时期。而雌雄成虫体内总脂肪含量在越冬开始就达到最高,分别为50.07%和47.93%,随后又逐渐降低,越冬期间显著高于其他时期。由此可知异色瓢虫自然种群的耐寒性呈现出明显的季节性变化,文中还就异色瓢虫自然种群耐寒性影响因素及其越冬策略进行了讨论。     

环境颜色对异色瓢虫生长发育及繁殖能力的影响

在室内利用不同颜色的饲养容器,对异色瓢虫Harmonia axyridis (Pallas) 生长发育、体长体重变化及繁殖能力进行了比较研究。结果显示：不同环境颜色条件对异色瓢虫幼虫各龄历期均有显著影响; 尽管蛹期受不同颜色影响显著,但其总胚后发育期在各处理间差异不显著。异色瓢虫1龄和2龄幼虫体长增量在不同颜色处理间无显著差异,但3龄幼虫在红色条件下体长增量显著小于其余各处理。不同环境颜色条件下异色瓢虫各虫期体重增量均有显著差异,而4龄幼虫体重增量在各处理中均显著大于其余各虫期,并占总胚后发育期体重增量的50%以上。异色瓢虫成虫的交配持续时间在各处理间无显著差异,但其产卵前期在黄色及绿色条件下显著小于其余各处理。其首堆产卵量在各处理间无显著差异,但在红色及自然光下的48 h累计产卵量均显著小于其余处理。     

Habitat generalization of a predatory ladybird,Harmonia yedoensis (Coleoptera: Coccinellidae), in an allopatric area with respect to its sibling species Harmonia axyridis

In central Japan, Harmonia yedoensis is a specialist ladybird that is confined to pine tree habitats, whereas its sibling species Harmonia axyridis is a generalist that feeds on a wide range of aphid species in nature. Interestingly, H. axyridis is not distributed in the Ryukyu Archipelago, southern Japan. We hypothesized that the ecological niche of H. yedoensis should be wider in the Ryukyu Archipelago, where its competitor species in central Japan, H. axyridis, is absent. We undertook fieldwork and a survey of published works to examine habitat utilization by H. yedoensis in the Ryukyu Archipelago. We found that H. yedoensis adults in the Ryukyu Archipelago visited several kinds of deciduous trees, including wild tamarind, Chinese hibiscus, Taiwan cherry and Malayan banyan, as well as pine trees. These observations suggest that habitat generalization has occurred in H. yedoensis in the Ryukyu Archipelago, where it does not compete with H. axyridis.