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1.
《Journal of Asia》2014,17(3):295-301
Proboscis sensilla are important for feeding biology in Lepidoptera, and are also valuable characters for species recognition and phylogenetic analysis. However, proboscis has not been satisfactorily explored in many groups in Lepidoptera so far. Here we examined the proboscis sensilla of the black cutworm Agrotis ypsilon (Rottemberg), a cosmopolitan agricultural pest of great economic significance, using scanning electron microscopy. Three types of sensilla were found on the proboscis: sensilla chaetica, sensilla basiconica, and sensilla styloconica. Sensilla chaetica occur only on the external surface of the proboscis and become shorter and more scattered toward the tip. Sensilla basiconica are arranged in longitudinal rows on the external proboscis and one longitudinal row in the inner food canal. Sensilla styloconica are the most characteristic sensilla on the proboscis, consisting of a single sensory cone inserted at the top of a stylus with six or seven longitudinal ribs, and are concentrated on the tip region, and are much longer and more numerous in females than in males. The role of proboscis sensilla in the feeding habit prediction is briefly discussed.  相似文献   

2.
Asclepiad pollinaria (including pollen masses) attach to diverse body parts of flower visitors in many ways. In this paper, we observed nocturnal moths (Lepidoptera: Pyralidae and Noctuidae) transporting the pollinaria of the Japanese species Metaplexis japonica (Thunb.) Makino (Apocynaceae: Asclepiadoideae) on the tip of the proboscis. Flowers of this species may induce nectar-feeding moths to pull out the proboscis along a guide rail (anther slit), thus clipping the pollinaria onto the tip of the proboscis and transferring the pollinaria to the next flower. The transfer of pollinaria on the unique vector of a moth proboscis tip is an interesting pollination mechanism among previously reported entomophiles.  相似文献   

3.
Proboscis length, the length of the tip, the number and length of the various sensilla throughout the proboscis, and the size and shape of the labial palpi were compared in 25 species of pollen-feeding and non-pollen-feeding Heliconiinae (Lepidoptera, Nymphalidae). The mouthparts of pollen-feeding species (all belonging to the genera Heliconius and Laparus) do not have structures exclusive to them. However, in comparison with non-pollen-feeding Heliconiiti, the pollen-feeding species have a significantly longer proboscis without elongation of the tip-region ; the bristle-shaped sensilla trichodea were found to be significantly more numerous and longer on the proximal and mid-region of the proboscis, while the sensilla of the tip-region are significantly shorter. In addition to these proboscis features, the labial palpi were shorter in the pollen-feeding species, which is likewise possibly associated with pollen-feeding behavior. The biological role of these features is discussed and the evolution of this unique feeding behavior among Lepidoptera is considered in the context of the phylogenetic relationships among genera of Heliconiini.  相似文献   

4.
 Morphology and distribution of the proboscis sensilla in Vanessa cardui have been investigated in order to contribute to the understanding of flower-probing behaviour in butterflies. The proboscis has a bend region approximately one-third of the length from the base. A short tip region is characterized by rows of intake slits leading into the food canal. Along the dorsal, lateral and ventral sides of the proboscis, sensilla trichodea, sensilla basiconica and sensilla styloconica are distributed in varying patterns depending on their distance from the b ase. The medial food canal bears one longitudinal row of sensilla basiconica only. The bristle-shaped sensilla trichodea are longer in the proximal region of the proboscis and become gradually shorter towards the tip. They are most frequent in number near to the bend region and near the beginning of the tip region. Sensilla basiconica arranged in longitudinal rows increase in number the more distal they are on the proboscis. The tip region is characterized by rows of sensilla styloconica on the dorsal side whereas the sensilla trichodea are mostly restricted to the ventral side. The ultrastructure suggests that the aporous sensilla trichodea function as mechanosensilla while the uniporous sensilla basiconica act as contact chemosensilla. The sensilla styloconica are regarded as bimodal contact chemo/mechanosensilla since their sensory cones are equipped with a single terminal pore and a tubular body at the base. The mouthpart sensilla appear to provide tactile cues on the positioning of the proboscis and on the degree of its insertion into a floral tube. Furthermore, they receive chemical stimuli on the availability of nectar and on the immersion status of the food canal. Accepted: 12 September 1997  相似文献   

5.
The structure of seven local bumblebee communities was studied in eastern Finland. The number of species in the study sites varied from 5 to 10, 11 being the number in the species pool. Most of the species (queens) had proboscis lengths of 8–11 mm. When floral resources were analysed on the basis of corolla tube depths, a group was found between 4 and 8 mm. In terms of flower utilization, species with similar proboscises had higher pairwise niche overlaps than species differing by their proboscis lengths.
Spacing between neighbouring species along the proboscis length dimension was not more uniform in the realized communities than what was expected on the basis of random draws from the local species pool. The results were the same for all species observed in the communities and for the abundant species only (frequency >5%), although competition among species in the latter group is expected to be more intense.
When the structure of bumblebee communities and of floral resources was expressed in terms of diversity of proboscis lengths and corolla tube depths, respectively, a positive correlation was found. Data suggest that species with similar proboscis tend to co-occur on fields with availability of appropriate corolla tubes.  相似文献   

6.
The form and function of the hesperiid feeding apparatus was studied in detail. The butterflies in the family Hesperiidae are of particular interest because the longest proboscis ever recorded in Papilionoidea was found in the Neotropical genus Damas. We focused on the functional morphology by comparing proboscis morphology as well as size and composition of both the stipes pump and the cibarial suction pump in skippers with short and extremely long proboscis. Results revealed that all studied Hesperiidae have the same proboscis micromorphology and sensilla endowment regardless of the proboscis length. However, the numbers of internal muscles of the proboscis, the morphology of the stipes pump as well as the pumping organs for nectar uptake are related to the proboscis length. We conclude that the low number of tip sensilla compared to proboscis length is responsible for remarkably longer manipulation times of long‐proboscid species during flower visits. The organs for proboscis movements and nectar uptake organs are well tuned to the respective proboscis length and are accordingly bigger in species with a proboscis that measures twice the body length.  相似文献   

7.
This study examined invertebrate floral visitor responses to floral richness, floral abundance, and distance between floral patches within a newly planted pollinator restoration habitat in an arid ecosystem in central Arizona, United States. We created a pollinator habitat experiment consisting of a large central garden (11‐m diameter) surrounded by concentric rings of smaller habitat patches (1‐m diameter), separated from one another by 1, 8, 13, and 21 m, respectively, and including four flowering species. We observed plant and visitor interactions via structured 10‐minute flower visitation observations over a 3‐month period. Key findings included: (1) each plant species interacted with a variety of flower visitors, but flower visitor groups differed only marginally among the plant species; (2) floral patches outside the central garden exhibited reduced quantities of floral structures; and (3) number of floral structures per patch, but not isolation of floral patches within the habitat, affected the number of visitors and visitor taxa richness. For practitioners and land managers looking to restore pollination systems in arid ecosystems with low establishment via seeding, the results of this study suggest that installing species‐rich and florally abundant patches of flowering plant species within a habitat could efficiently support plant‐pollinator interactions.  相似文献   

8.
Many angiosperms have arranged their flowers in inflorescences forming a distinct signalling unit to flower visitors. In some species, the flowers of inflorescences undergo a temporal colour change corresponding exactly to a change in the reward status. Based on information obtained from the spectral reflection curves of pre-change and postchage colours of flower corollas and/or floral guides, it was possible to demonstrate that the colour phase associated with reward closely corresponds to the visual stimuli which trigger behavioural responses of inexperienced flower visitors, and that the colour phase associated with less reward corresponds to visual stimuli less attractive to naïve flower visitors. Reciprocal colour changes were not observed. It is to be assumed that the unidirectionality of floral colour changes is an adaptation of angiosperms aimed at the guidance of first-time flower visitors. Signalling reward to inexperienced flower visitors is an additional function of floral colour changes. The main function of floral colour changes, however, is to provide cues with which the flower visitors can learn to associate one colour phase with reward.  相似文献   

9.
Although Chamaecrista Moench genus is a very important source of pollen to bees in the Cerrado, this relationship is almost unknown. Within flower visitors of Ch. debilis, we found hymenopterans (Apidae) as the most abundants, but Coleoptera (Buprestidae) and Lepidoptera (Noctuidae) were also collected. Bees of great size are pointed out as effective pollinators of Cassiinae. Only five out of seventeen species of floral visitors of Ch. debilis sampled in cerrado, are indicated as possible pollinators, from which four species were not previously indicated in other papers.  相似文献   

10.
Few species of true butterflies (Lepidoptera: Papilionoidea) have evolved a proboscis that greatly exceeds the length of the body. This study is the first to examine the morphology of an extremely long butterfly proboscis and to describe how it is used to obtain nectar from flowers with very deep corolla tubes. The proboscis of Eurybia lycisca (Riodinidae) is approximately twice as long as the body. It has a maximal length of 45.6?mm (mean length 36.5?mm?±?4.1?S.D., N?=?20) and is extremely thin, measuring only about 0.26?mm at its maximum diameter. The proboscis has a unique arrangement of short sensilla at the tip, and its musculature arrangement is derived. The flower handling times on the preferred nectar plant, Calathea crotalifera (Marantaceae), were exceptionally long (mean 54.5?sec?±?28.5?S.D., N?=?26). When feeding on the deep flowers remarkably few proboscis movements occur. The relationship between Eurybia lycisca and its preferred nectar plant and larval host plant, Calathea crotalifera, is not mutualistic since the butterfly exploits the flowers without contributing to their pollination. We hypothesize that the extraordinarily long proboscis of Eurybia lycisca is an adaptation for capitalizing on the pre-existing mutualistic interaction of the host plant with its pollinating long-tongued nectar feeding insects.  相似文献   

11.
1. The flower visitor community consists not only of pollinators but also of non‐pollinators, such as florivores, thieves and predators that attack flower visitors. Although there is increasing evidence that early‐season foliar herbivory influences pollinator visitation through changes in floral traits, few studies have explored indirect effects of foliar herbivory on community structure of the flower visitors. We examined how early‐season foliar herbivory influences the flower visitor community established in late season. 2. We conducted an inoculation experiment using a lacebug (Corythucha marmorata), which is a predominantly herbivorous insect attacking leaves of tall goldenrod (Solidago altissima) in Japan. 3. Flower abundance significantly decreased when damaged by the lacebug. The numbers of pollinators, florivores and thieves were positively correlated with flower abundance, whereas predators were not. In response to flower abundance, florivores decreased on damaged plants. On the other hand, thieves increased on damaged plants, and pollinators and predators did not differ between damaged and undamaged plants. 4. When effects of flower abundance were excluded, foliar herbivory still influenced florivores negatively and thieves positively. This implies that factors besides flower abundance may have affected the numbers of florivores and thieves. 5. Community composition of flower visitors on damaged plants significantly differed from undamaged plants, although overall abundance, taxonomic richness and taxonomic evenness were unaffected by foliar herbivory in the early season. It is important to recognise that only evaluating species diversity and overall abundance may fail to detect the significant consequence of early‐season herbivory on the flower visitor community.  相似文献   

12.
The main goal of the present study was to test if two sympatric species of Heliconia, Heliconia spathocircinata and Heliconia laneana var. flava, differ in their reproductive seasons and guilds of flower visitors. Twenty-four sampling sessions were conducted monthly between February 2001 and January 2003. Individuals of H. spathocircinata and of H. laneana var. flava were tagged within a transect of 4000×4 m. Reproductive phenophases (flowering, unripe, and ripe fruits) were recorded, and circular statistics were used to test for the regularity and frequency of phenophases. Flower visitors were observed during two flowering periods for each species. Both species had well-defined and synchronous reproductive periods, with a small overlap, suggesting a sequential flowering model. Biotic and abiotic factors seem to affect phenophases of both species. However, herbarium data suggest that the flowering period in H. spathocircinata varies less than in H. laneana, despite its wider geographic distribution. The hummingbird Phaethornis idaliae was the main floral visitor of both Heliconia species studied. H. laneana was also legitimately visited by another hummingbird species, Glaucis hirsuta, and by Lepidoptera. Some Lepidoptera, particularly the bee Trigona spinipes, were illegitimate visitors (‘nectar robbers’). We suggest that the flower of H. spathocircinata allowed a wider array of visitors, because it is bigger.  相似文献   

13.
三种夜蛾成虫口器感器的超微形态   总被引:1,自引:0,他引:1  
为确定不同种类夜蛾口器及其感器在超微结构上的差异, 采用扫描电子显微镜对棉铃虫Helicoverpa armigera (Hübner)、 烟夜蛾H. assulta (Guenée)和银纹夜蛾Argyrogramma agnata (Staudinger)3种鳞翅目(Lepidoptera)夜蛾科(Noctuidae)重要农业害虫雌、 雄成虫口器感器的超微形态进行了观察和比较。结果表明: 3种夜蛾雌、 雄成虫口器感器类型均无明显差异。棉铃虫和烟夜蛾口器感器在类型和形状上十分类似, 均具有毛形、 锥形和栓锥形感器; 喙管末端的栓锥感器粗、 密, 棱纹明显。银纹夜蛾口器感器与两种铃夜蛾区别明显, 除上述3类感器外, 还具有腔锥形感器; 其喙管末端的栓锥感器细、 疏, 棱纹不明显。结果显示口器感器可用于夜蛾的分类及亲缘关系研究。  相似文献   

14.
As flower visitors, ants rarely benefit a plant. They are poor pollinators, and can also disrupt pollination by deterring other flower visitors, or by stealing nectar. Some plant species therefore possess floral ant-repelling traits. But why do particular species have such traits when others do not? In a dry forest in Costa Rica, of 49 plant species around a third were ant-repellent at very close proximity to a common generalist ant species, usually via repellent pollen. Repellence was positively correlated with the presence of large nectar volumes. Repellent traits affected ant species differently, some influencing the behaviour of just a few species and others producing more generalised ant-repellence. Our results suggest that ant-repellent floral traits may often not be pleiotropic, but instead could have been selected for as a defence against ant thieves in plant species that invest in large volumes of nectar. This conclusion highlights to the importance of research into the cost of nectar production in future studies into ant-flower interactions.  相似文献   

15.
Animal-pollinated angiosperms either depend on cross-pollination or may also reproduce after self-pollination—the former are thus obligately, the latter facultatively dependent on the service of animal-pollinators. Analogously, flower visitors either solely feed on floral resources or complement their diet with these, and are hence dependent or not on the flowers they visit. We assume that obligate flower visitors evolved abilities that enable them to effectively forage on flowers including mechanisms to bypass or tolerate floral defences such as morphological barriers and repellent/deterrent secondary metabolites. Facultative flower visitors, in contrast, are supposed to lack these adaptations and are often prevented to consume floral resources by defence mechanisms. In cases where obligate flower visitors are mutualists and facultative ones are antagonists, this dichotomy provides a solution for the plants'' dilemma to attract pollinators and simultaneously repel exploiters. In a meta-analysis, we recently supported this hypothesis: obligate flower visitors are attracted to floral scents, while facultative ones are repelled. Here, we add empirical evidence to these results: bumblebees and ants, obligate and facultative flower visitors, respectively, responded as predicted by the results of the meta-analysis to synthetic floral scent compounds.Key words: antagonists, exploitation, floral defences, mutualism, nectar, pollinationThe mutualism between flowers and their pollinators is often exploited by cheaters that consume floral rewards but do not contribute to or even reduce the reproductive success of plants.1 The classification into mutualistic and antagonistic flower visitors represents a phytocentric point of view and only considers the interaction''s net effect for the plant. However, the outcome of each plant-flower visitor interaction may be highly conditional and variable over time2 and thus constitutes a continuum between beneficial and detrimental, and it may not be unequivocally assigned to be either positive or negative. Furthermore, many flower visitor species that function as effective pollinators of some plant species represent severe antagonists to other plant species.3 Thus, except for highly specialised systems, it is difficult to predict whether an interaction is mutualistic, commensalistic or antagonistic. We proposed a different classification of flower visitors based on the animals'' interest in flower visits.4 Animals visit flowers primarily in search for food; pollination is just a secondary effect.5 For some taxa nectar and pollen are the sole nutrient supply, others only supplement their more generalistic diets with floral resources. These different dependencies on floral resources can often be unequivocally assigned to each animal species. Bees, for example, strongly depend on pollen and nectar and are thus obligate flower visitors. In contrast, ants are omnivores and thus facultative flower visitors that consume large amounts of floral nectar of some plant species but obtain most of the nutrients required by the colony from non-floral resources.6Optimal foraging theory predicts that animals evolve physiological and behavioral features that allow them to exploit their resources as effectively as possible.7,8 Therefore, a classification considering the animals'' dependencies on floral resources (obligate versus facultative) may be better suited to explain adaptations to flower visits than their effect on plants'' reproduction (mutualistic versus antagonistic). One very important adaptation to the consumption of floral resources is the ability to tolerate or overcome floral defences that are employed by the flowers to reduce the visitation frequency of detrimental flower visitors.9 Floral scents are innate attractants or reinforce floral visits due to associative learning but do also serve as effective repellents against antagonists.10 In a meta-analysis, we recently demonstrated that the dependency on floral resources determines the responses to floral scents.4 In the bioassay presented here, using bumblebees (Bombus terrestris) and ants (Lasius niger), we empirically tested the predictions deduced from the metaanalysis. We expected that bumblebees—as obligate flower visitors—are attracted to floral scent compounds, while ants—as facultative flower visitors—are repelled.  相似文献   

16.
Butterfly pollination in the tropics is considered somewhat effective or solely effective in a few plant species. In the present study, we tested the hypothesis that Mandevilla tenuifolia (Apocynaceae), which has floral attributes associated with psychophily, has strategies adapted to pollination by butterflies, restricting other floral visitors and making these insects act as efficient pollinators. We analysed the floral and reproductive biology of M. tenuifolia, as well as the frequency and efficiency of its flower visitors. M. tenuifolia is an herb whose flowers have strong herkogamy and secondary pollen presentation on the style head, which corresponds to 60.4% of pollen on the anthers. Flower longevity and the long period of receptivity of the stigmatic region associated with the large amount of pollen removed in the first visits suggest that flowers remain functionally female during part of anthesis. Butterflies, mainly of the families Nymphalidae and Pieridae, are the only pollinators of M. tenuifolia. Despite being self‐compatible, M. tenuifolia depends on biotic vectors for fruit production. A non‐significant difference in fruit set between controlled treatments and natural conditions suggests that the pollinators are efficient. The inclination resulting from the landing of butterflies on flowers, together with flower morphology, guiding the insect proboscis inside the floral tube, as well as the frequency and efficiency of butterfly visits, are evidence of the close relationship between butterflies and M. tenuifolia, and also of the efficiency of these insects as pollinators.  相似文献   

17.
Pollination networks are usually constructed and assessed by direct field observations which commonly assume that all flower visitors are true pollinators. However, this assumption is often invalid and the use of data based on mere visitors to flowers may lead to a misunderstanding of intrinsic pollination networks. Here, using a large dataset by both sampling floral visitors and analyzing their pollen loads, we constructed 32 networks pairs (visitation versus pollen transport) across one flowering season at four elevation sites in the Himalaya–Hengduan Mountains region. Pollen analysis was conducted to determine which flower visitors acted as potential pollinators (pollen vectors) or as cheaters (those not carrying pollen of the visited plants). We tested whether there were topological differences between visitation and pollen transport networks and whether different taxonomic groups of insect visitors differed in their ability to carry pollen of the visited plants. Our results indicated that there was a significantly higher degree of specialization at both the network and species levels in the pollen transport networks in contrast to the visitation networks. Modularity was lower but nestedness was higher in the visitation networks compared to the pollen transport networks. All the cheaters were identified as peripheral species and most of them contributed positively to the nested structure. This may explain in part the differences in modularity and nestedness between the two network types. Bees carried the highest proportion of pollen of the visited plants. This was followed by Coleoptera, other Hymenoptera and Diptera. Lepidoptera carried the lowest proportion of pollen of the visited plants. Our study shows that the construction of pollen transport networks could provide a more in‐depth understanding of plant–pollinator interactions. Moreover, it suggests that detecting and removing cheater interactions when studying the topology of other mutualistic networks might be also important.  相似文献   

18.
ABSTRACT

Background: Little information is available about life history of páramo plants such as phenology and plant-animal interactions.

Aims: We analysed phenological patterns of flowering and characterised the structure of a plant-pollinator network in a Venezuelan páramo in order to identify key species in this ecosystem.

Methods: We counted the number of individuals with flowers of 76 native plant species and recorded their pollinators in 16 permanent plots between 3000 and 4200 m monthly for three years. We used this dataset to develop a plant-pollinator network, on which nine different metrics related to structural properties were calculated.

Results: The flowering of most species concentrated during the rainy season (between May and November), however some species have continuous flowering. The guild of floral visitors included hummingbirds, flower piercers, bumblebees, Diptera and Lepidoptera. The plant – flower visitor interaction network did not exhibit nestedness, but showed a significant specialization index (H2) and high values of functional complementarity.

Conclusions: Páramo plants have the capacity of maintaining a resident nectarivorus fauna (bumblebees and hummingbirds) because of continuous flower offer during the year. However, the plant – pollinator network identified could be very sensitive to the loss component species, owing to high levels of specialisation and functional complementarity.  相似文献   

19.
Floral nectary structure and nectar sugar composition were investigated in relation to other floral traits and flower visitors in contrasting species of Nyctaginaceae from southern South America, representing four tribes (Bougainvilleeae, Colignonieae, Nyctagineae, Pisoneae). Our comparative data will aid in the understanding of plant–pollinator interactions and in the development of hypotheses on the origin of floral and reproductive characters in this family. The nectaries are located on the inner side of the staminal tube. The nectariferous tissue is composed of an epidermis and three to ten layers of secretory parenchymal cells, supplied indirectly by the filament vascular bundles. Stomata appear to be associated with nectar secretion. For the first time in Nyctaginaceae, nectary ultrastructure is described in Boerhavia diffusa var. leiocarpa. Nectary parenchyma cells are densely cytoplasmic and contain numerous starch grains. Plasmodesmata connect the nectariferous cells. Flowers of Nyctaginaceae secrete a small volume of nectar of variable concentration (10–47%). Nectar is dominated by hexoses, but Mirabilis jalapa showed a balanced proportion of sucrose and hexoses. Hymenoptera are the most common visitors for most species; nocturnal Lepidoptera are the most common visitors for M. jalapa and Bougainvillea stipitata. We found relatively low variation in the nectary characteristics of Nyctaginaceae compared with broad variation in flower structure, shape, colour and nectar traits. © 2013 The Linnean Society of London  相似文献   

20.
Concerted changes in flower morphology and pollinators provide strong evidence on adaptive evolution. Schizanthus (Solanaceae) has zygomorphic flowers and consists of 12 species of annual or biennial herbs that are distributed mainly in Chile and characterized by bee-, hummingbird-, and moth-pollination syndromes. To infer whether flowers diversified in relation to pollinator shifts, we traced the evolutionary trajectory of flower traits and visitors onto a phylogeny based on sequence data from ITS, waxy, and trnF/ndhJ DNA. Maximum-likelihood ancestral reconstruction of floral traits suggests that ancestral Schizanthus had a bee-pollination syndrome. The hummingbird syndrome evolved in S. grahamii, a high elevation species in the Andes. The moth syndrome evolved in the ancestor of three species that inhabit the Atacama Desert. Results of mapping flower visitors onto the phylogeny show that the shift from bee to hummingbird pollination concurred with a shift in pollinators as predicted by the syndromes. However, the same pattern was not found for the moth syndrome. Visits by moths were observed only in one of the three moth-syndrome species, and at a very low rate. This mismatch suggests either anachronic floral characters or maintenance of rare, imperceptible moth pollination backed up by capacity for autonomous selfing. Overall, results suggest that diversification of flower traits in Schizanthus has occurred in relation to pollinator shifts.  相似文献   

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