异色瓢虫越冬聚集行为对其能量代谢的影响

异色瓢虫以成虫滞育越冬,越冬期间聚集行为尤为显著。为探讨异色瓢虫越冬聚集行为的适应意义,本研究利用便携式红外线CO2分析仪测定了6 种聚集度（分别用1头、2头、5头、10 头、20头和50头表示）下异色瓢虫越冬成虫的呼吸量,并通过呼吸量计算得到各聚集度下的呼吸速率（Respiration rate, Rr）和能量代谢速率（Metabolism rate, Rm）。结果表明: 不同聚集度间异色瓢虫越冬成虫的呼吸速率和能量代谢速率均存在显著性差异,相关性分析表明Rr和Rm值与聚集度之间呈显著负相关。即随着聚集度的增加,越冬成虫的呼吸速率和能量代谢速率呈逐渐降低的趋势。此外,利用“Y”形嗅觉仪测定了异色瓢虫实验种群和越冬种群成虫对不同味源的选择趋性,表明异色瓢虫均对各自的群体表现出趋性,而其越冬聚集行为的发生需要一种特殊的气味物质。本研究表明聚集行为可以有效降低异色瓢虫的新陈代谢速率,减少能量消耗,有利于其种群成功越冬,这对其越冬来说具有非常重要的意义。     

Is conspecific substrate marking a long‐term external memory of previously colonized overwintering sites in Harmonia axyridis?

The multicoloured Asian ladybeetle, Harmonia axyridis (Pallas), aggregates inside dwellings during winters to survive the cold. This beetle uses chemical cues coming from congeners to select an overwintering site. Recent research has shown that they preferentially gather at places where conspecifics previously laid a substrate marking made up of saturated and unsaturated hydrocarbons. Some authors have reported that H. axyridis colonizes the same overwintering sites from 1 year to another. Herein, the hypothesis that this substrate marking is used by H. axyridis to settle in the same aggregation sites from one winter to another was tested. To this aim, the temporal modification in the chemical profile of the hydrocarbon marking was studied by performing chromatographic analyses. After 1 year, the overall profile was modified qualitatively and quantitatively: the unsaturated hydrocarbons were no longer detected while some saturated hydrocarbons were still present in large quantities. In a behavioural assay conducted in the laboratory, the 12‐month‐old marking did not induce the aggregation of H. axyridis. This result indicates that the chemical markings left by conspecifics during a previous aggregation period in an overwintering site are not sufficient to induce the gathering of the newly arriving individuals.     

药剂处理有蚜烟叶对异色瓢虫选择行为的影响

【背景】植物挥发物的特性之一就是可变性,多种胁迫因子,如光照、干旱等,均可导致植物挥发物组分与含量发生改变,进而影响天敌搜索猎物的行为。【方法】本试验以杀虫剂作为影响植物挥发物的胁迫因子,利用“Y”形嗅觉仪观测8种杀虫剂处理有蚜烟叶后对异色瓢虫显明变种、显现变型和二斑变型选择行为的影响。【结果】异色瓢虫对健康无蚜烟叶无明显趋性;与洁净空气相比,异色瓢虫对无药剂处理有蚜烟叶的选择率为70％～74％。在氧乐果处理后,异色瓢虫显明变种、显现变型和二斑变型对有蚜烟叶的选择率分别为32％、36％和34％,氟虫腈·高氯处理后,其选择率分别为36％、38％和36％,多杀霉素处理后,其选择率分别为40％、42％和38％,异色瓢虫对这3种杀虫剂处理有蚜烟叶的趋性明显降低;吡虫啉处理后,其选择率分别为64％、62％和60％,啶虫脒处理后,其选择率分别为62％、68％和66％,这2种杀虫剂可略微降低瓢虫的趋性反应;氯氰菊酯处理后,其选择率分别为80％、82％和80％,氯氟氰菊酯处理后,其选择率均为78％,氟氯氰菊酯处理后,其选择率分别为76％、78％和76％,这3种杀虫剂可增强瓢虫的趋性反应。【结论与意义】杀虫剂可能会对烟草挥发物的组分和含量产生影响,但不同的杀虫剂影响效果不同。     

Substrate Marking by an Invasive Ladybeetle: Seasonal Changes in Hydrocarbon Composition and Behavioral Responses

The multicolored Asian ladybeetle, Harmonia axyridis (Pallas), aggregates inside dwellings during the winter to survive the cold. Recent published reports have highlighted that overwintering individuals use hydrocarbon markings deposited on surfaces by conspecifics to orient toward aggregation sites. In the current study, monthly GC-MS analyses revealed seasonal modifications in the chemical profile of substrate markings deposited by moving individuals. The markings of overwintering ladybeetles contained larger proportions of heptacosadiene, nonacosadiene, hentriacontadienes, and methyl-nonacosanes, along with a lower proportion of heptacosene and nonacosene. This finding suggests the importance of the unsaturated and/or branched hydrocarbons in the H. axyridis aggregation process. Subsequently, we conducted behavioral assays to test whether (1) there is seasonal variation in the behavioral response of H. axyridis individuals toward substrate markings deposited by conspecifics in the same physiological state and (2) the observed behavioral modification is due to a change in ladybeetle sensitivity and/or a change in the chemical composition of the substrate marking. The results indicate that overwintering individuals exhibit a stronger “following” response toward conspecific substrate markings. This behavior is linked to both the physiological state of ladybeetles and the specific chemical profile of the marking biomolecules deposited under overwintering conditions.     

Using species distribution models to locate animal aggregations: a case study with Hippodamia undecimnotata (Schneider) overwintering aggregation sites

1. The protection of animals' aggregation sites is increasingly seen as a key conservation strategy. However, to efficiently protect aggregation sites, they need to be accurately located. Species distribution models (SDMs) are an important tool in biological conservation to predict spatial distribution of species and they are used here to predict the distribution of the aggregation sites of a ladybird (Coleoptera: Coccinellidae) species. 2. Hippodamia undecimnotata forms spectacular overwintering aggregations at the same locations every year across southern and eastern Europe. In this study, an SDM was developed and its performance tested for H. undecimnotata aggregations in southwest France. Moreover, the study looked at how environmental variables correlate with ladybirds' abundance in the aggregation sites. 3. The occurrence of aggregations was best described by one model including isolated prominent object, pesticide risk, altitude and vegetation coverage. Furthermore, ladybird abundance at the aggregation sites is positively correlated with altitude. The SDM occurrence model performance was found to be high (area under the curve = 0.92 and true skill statistic = 0.78). 4. It is suggested that H. undecimnotata may be an umbrella species, because some aggregation sites were also used by other ladybird species. Therefore, the protection of the aggregation sites of this species may benefit several other species. 5. This study provides nature conservation stakeholders with a tool to locate overwintering aggregations, a first step towards the protection of these sites.     

Is Contact Between Conspecifics Involved in the Cohesion of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) Aggregations?

The multicolored Asian ladybeetle, Harmonia axyridis (Pallas), exhibits a gregarious behavior during unfavorable winter conditions. Although this behavior is currently described as a phenomenon occurring only during winter, H. axyridis aggregations can also be observed outside overwintering conditions. However, the substrate markings previously highlighted as being involved in the wintry aggregation of this exotic species do not seem to be used by non-overwintering individuals to aggregate. This fact suggests then that other cues are responsible for the induction of this behavior. In this work, we have tested the hypothesis that direct contact between non-overwintering individuals stimulates the establishment of clusters. Binary choice experiments highlighted the involvement of elytral cuticular compounds in this phenomenon. Chromatographic analyses showed that the active extracts contained mainly hydrocarbons, including saturated, mono-unsaturated, and di-unsaturated homologues. Physical contact also seems to be involved in the non-overwintering aggregative behavior of H. axyridis, but to a lesser extent than these natural compounds. These findings could eventually be used to develop new control methods of these pest populations and so, reduce the adverse impacts it causes on biodiversity.     

Impact of fruit feeding on overwintering survival of the multicolored Asian lady beetle, and the ability of this insect and paper wasps to injure wine grape berries

The establishment of the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), in North America has resulted in negative impacts on fruit production. We investigated the overwintering survival of H. axyridis after feeding on four diets: injured wine grape berries, 25% sucrose solution, water, and a control containing no food or water. After being exposed to these diets for 6 days, live individuals were transferred to clean plastic Petri dishes, and held at 5 ± 1 °C in growth chambers throughout the winter. Survival was recorded every month. Adult lady beetles collected during the overwintering flight in mid-October had higher survival rates than beetles collected from soybean fields in mid-August. These results suggest that an adaptation period prior to diapause increases the chances of lady beetle survival over the winter. In addition, injured wine grape berries, sugar, and water decreased beetle mortality during the overwintering months. Our results also showed that under similar conditions, females have higher survival during the winter than males. The importance of sugar and water on winter survival may drive H. axyridis adults to vineyards for feeding on wine grapes. Finally, we tested if adults of H. axyridis and the European paper wasp, Polistes dominulus Christ (Hymenoptera: Vespidae), were able to break the grape skin. Harmonia axyridis adults and paper wasps were not able to cause the primary injury to berries of Frontenac grapes under laboratory conditions. These results suggest that control of paper wasps in vineyards may not affect H. axyridis aggregations, and that H. axyridis feeding on wine grapes depends on previous injury to grape berries.     

异色瓢虫对与本土蚜虫共存的外来扶桑绵粉蚧的搜寻和捕食行为

[目的]外来入侵物种作为猎物可能影响本土广谱捕食者的搜寻和捕食行为.本研究旨在揭示异色瓢虫Harmonia axyridis对与本土豌豆修尾蚜Megoura japonica混合发生的外来入侵扶桑绵粉蚧Phenacoccus solenopsis的搜寻和捕食行为.[方法]试验前对异色瓢虫设两个饲喂猎物种类处理:用扶桑绵...     

Winter survival of Harmonia axyridis in The Netherlands

Since the establishment of Harmonia axyridis in Europe, populations of native ladybirds have decreased. Overwintering survival is one of the aspects of the biology of H. axyridis that may contribute to its firm establishment in and invasion of a new area. In this study winter survival of five wild H. axyridis populations was assessed under natural and semi-natural conditions, with a focus on the potential influence of location and orientation on winter survival.Overwintering survival of H. axyridis in the Netherlands is high: 70.8-88.2%. When overwintering at one central site, populations sampled at five locations showed statistically significant different mortality rates. Furthermore, winter survival of H. axyridis at the sample sites was higher when beetles were hibernating at the southwestern sides of buildings, where most aggregations of ladybirds were found. Survival was higher at sheltered sites compared to exposed sites.Harmonia axyridis has a comparable or higher overwintering survival than most common native ladybird species. A high overwintering survival results in a large post-hibernation population in spring, leading to a rapid population build-up. Thus, the high winter survival probably contributes to the success of the exotic H. axyridis.     

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.     

Harmonia axyridis (Coleoptera: Coccinellidae) in buildings: relationship between body height and crevice size allowing entry

Although the introduced lady beetle Harmonia axyridis (Pallas) (Coleoptera: Coc-cinellidae) is an important predator of aphids in a variety of crop systems during the growing season, it is often a pest in fall and winter when it enters buildings seeking overwintering sites. One of the primary recommendations for managing this annual influx is to prevent beetle entry by caulking or otherwise filling potential entry points in buildings. The goal of this study was to determine how small a gap the beetles are able to enter in choice and no-choice studies by experimentally exploiting their behavioral tendency to seek dark shelters at cool temperatures. Within the size range of adults collected in central North Carolina in 2003 (1.99-3.29 mm body height), no beetles entered a 2-mm access during no-choice experiments. Most (83%) entered a 3-mm gap; those failing to cross the 3-mm threshold were significantly larger than those that traversed it. In choice experiments, 98.2% of beetles entered shelters. As in the previous study, no beetles entered shelters with 2-mm gaps. Significantly fewer were found in shelters with 3-mm entrances than in those with 4- or 5-mm access; beetles that entered 3-mm gaps were significantly smaller than the remainder of the test population. Although no H. axyridis crossed a 2-mm threshold in either experiment, a gap of this size may nonetheless allow admission if it has flexible borders (e.g., foam weather stripping); beetles were observed attempting forced entry into too-small crevices.     

Phytophagous preferences of the multicolored Asian lady beetle (Coleoptera: Coccinellidae) for autumn-ripening fruit

The objective of this study was to assess the potential pest status of Harmonia axyridis (Pallas) on autumn-ripening fruit. In autumn, H. axyridis has been observed feeding on pumpkins, apples, grapes, and raspberries in Minnesota. To determine whether H. axyridis can inflict primary feeding damage to fruit (i.e., breaking the skin of the fruit), we conducted laboratory feeding experiments with undamaged pumpkins, apples, grapes, and raspberries. The only fruit that H. axyridis was able to damage directly was raspberry. Laboratory choice tests were conducted to determine whether H. axyridis exhibits a preference between damaged and undamaged fruit, between cultivars of fruit, and between sugar water and water alone. For all fruits tested, H. axyridis showed a preference for damaged fruits over undamaged fruits. H. axyridis also exhibited a strong preference for sugar water over water alone. However, few differences were exhibited in preference between cultivars of fruit. In autumn, it seems that H. axyridis is an opportunist, taking advantage of previously damaged fruit, caused by other agents.     

Susceptibility of a native and an exotic lady beetle (Coleoptera: Coccinellidae) to Beauveria bassiana

The exotic multicolored Asian lady beetle, Harmonia axyridis, became established and recently spread across much of North America and southern Canada. In a habitat now used by both the invading H. axyridis and a native lady beetle, Olla v-nigrum, we discovered that the native lady beetle was commonly infected by Beauveria bassiana; whereas, the exotic H. axyridis, was not. Laboratory assays revealed that B. bassiana isolates collected from naturally infected O. v-nigrum were pathogenic to adult O. v-nigrum but not to adult H. axyridis. In contrast, the GHA strain of B. bassiana was not significantly pathogenic to O. v-nigrum nor H. axyridis. Late-season field collections revealed significantly higher B. bassiana infection of O. v-nigrum than H. axyridis. Our results lead us to hypothesize that low susceptibility of H. axyridis to B. bassiana (found to infect O. v-nigrum) may provide an intraguild advantage to H. axyridis over O. v-nigrum; this may also occur with other species of native lady beetles and other endemic entomopathogens in different habitats and regions.     

Cuticular hydrocarbon profiles and aggregation in four Periplaneta species (Insecta: Dictyoptera)

Cuticular hydrocarbon (CH) profiles of four Periplaneta species were compared and their role in aggregation and interspecific recognition was evaluated. CH profiles are species specific and include from 19 to 25 hydrocarbons. P. brunnea, P. fuliginosa and P. australasiae have more CH components in common with one another than with P. americana. P. americana hydrocarbons include components from 24 to 43 carbon atoms but hydrocarbons for the three other species range from 21 to 41 atoms. The major compound in CH profiles in P. americana is 6,9-heptacosadiene that is absent from the three other species. The major compound in CH profiles of P. Brunnea and P. fuliginosa is 13-methyl pentacosane that is not found in the CH profile of P. americana. Major compounds in P. australasiae species are tricosene and 13-methyl pentacosane, respectively, in males and females. Binary choice tests demonstrated that specific CH extracts induced aggregation in the four species. High CH amounts were required to induce aggregation of P. americana and P. brunnea on conditioned sites, whereas low amounts were sufficient to induce aggregation of P. fuliginosa and P. australasiae. These results suggest that CHs are involved in aggregation and interspecific recognition.     

Long term changes in the communities of native ladybirds in Northern Italy: impact of the invasive species <Emphasis Type="Italic">Harmonia axyridis</Emphasis> (Pallas)

Since the mid-2000s, the exotic coccinellid species Harmonia axyridis (Pallas) has established itself in Northern Italy, raising serious concerns about possible repercussions on native ladybirds. In this study we compared the ladybird assemblages in 2015–2016 with those sampled in 1995–1996, before the arrival of H. axyridis. Surveys were carried out in the same sites and with the same methods for both periods. Aphidophagous ladybirds were sampled in hedgerows and herbaceous habitats at field margins by mechanical knockdown and sweeping net, respectively. The changes in the structure of ladybird communities after the arrival of H. axyridis were significantly different between arboreal and herbaceous habitats. Harmonia axyridis is currently the dominant species in shrubs and trees, and all the native ladybird species taken together account for only approximately one third of the total individuals sampled in 2015–2016. On the other hand, the relative abundance of the exotic species in herbaceous habitats was low, and it has had a negligible relevance on the structure of ladybird communities on grasslands. Among native species, Adalia bipunctata (L.), whose ecological niche largely overlaps with that of H. axyridis, suffered the largest decline between 1995–1996 and 2015–2016. The co-occurrence of H. axyridis invasion and the regression of A. bipunctata suggest a direct impact of the exotic species, because no other major modifications occurred in the studied areas between sampling periods.     

Genotypic diversity of Wolbachia pipientis in native and invasive Harmonia axyridis Pall., 1773 (Coleoptera,Coccinellidae) populations

The distribution and variability of reproductive symbiotic Wolbachia pipientis bacteria were studied in seven native and six invasive H. axyridis populations. Wolbachia-infected individuals were found in two invasive and two native populations. We demonstrated for the first time an infection of invasive H. axyridis populations with Wolbachia. Two new molecular forms of Wolbachia were detected by a system of multilocus typing. The supergroup A Wolbachia was found for the first time in H. axyridis. The detected genotypic diversity of Wolbachia indicates repeated and independent infection events in the evolutionary past of H. axyridis.     

Vulnerability of larvae of two species of aphidophagous ladybirds, Adalia bipunctata Linnaeus and Harmonia axyridis Pallas, to cannibalism and intraguild predation

Vulnerability of larvae of two species of aphidophagous ladybirds, Adalia bipunctata Linnaeus and Harmonia axyridis Pallas, to cannibalism and intraguild predation was assessed in the laboratory. In the first experiment, a first instar of one of the two above species was kept with a fourth instar of the other species in a Petri dish. The number of times each first instar larva was encountered by the fourth instar larva and the fate of the first instar was determined over a period of 10 min. The fourth instar larvae captured and killed all the first instar larvae of their own species at the first encounter. However, when presented with fourth instar larvae of the other species the first instar larvae of A. bipunctata and H. axyridis were encountered 6.4 ± 1.3 ( n  = 10) and 19.4 ± 2.1 ( n  = 10), respectively. In this experiment no first instar larvae of H. axyridis , whereas all those of A. bipunctata , were killed.     

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。     

Divergence in cuticular hydrocarbons between parapatric subspecies of the meadow grasshopper, Chorthippus parallelus (Orthoptera, Acrididae)

Two subspecies of the grasshopper Chorthippus parallelus (Orthoptera; Acrididae) meet and form a hybrid zone in the Pyrenees. Here we investigate whether the subspecies differ in the blend of cuticular hydrocarbons. Such differences may function as chemical signals, being detected via contact chemoreception and used during mate choice as in other insects. Gas chromatography shows that the subspecies have diverged in the composition of their cuticular hydrocarbons. This difference between subspecies exists over and above variation in cuticular hydrocarbons among individual populations. The majority of the difference can be attributed to the relative amounts of a small group of compounds present in the cuticle. The possible consequences of this chemical divergence for mating encounters between the subspecies are discussed.     

Aggregation behavior of Harmonia axyridis under non‐wintering conditions

The invasive multicolored Asian ladybeetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), aggregates inside dwellings during winter to avoid cold weather. This adaptive behavior disturbs homeowners, because of the large numbers of individuals that aggregate, which induces allergic reactions. The migratory flight patterns of this species have been well documented, with individuals preferentially moving toward prominent and high color contrast elements. However, the factors involved in the selection of aggregation sites by this species have yet to be elucidated. Here, we evaluated the influence of (i) the density of individuals and (ii) the type of available shelters on decisions by H. axyridis to settle and aggregate under shelters. A dual choice bioassay conducted in the laboratory demonstrated the presence of mutual attraction to conspecifics. We also found that individuals preferentially settled under red covered shelters compared to transparent shelters, and that the type of shelter outweighed the effect of social interactions among conspecifics. Moreover, this experiment was performed under non‐wintering conditions, providing the first evidence that aggregative behavior in this species can also occur under those specific conditions.