Deceptive Species Research Articles

How Effective Is Environmental Protection for Ensuring the Vitality of Wild Orchid Species? A Case Study of a Protected Area in Italy.

Orchids are among the plants most threatened by anthropic impact and environmental changes. Therefore, all known orchid species are protected in several countries by regional, national and international legislation. Several studies have cast doubts on the effectiveness of legislation to ensure the protection of wild orchids. We assessed the vitality of four orchid populations in a coastal area in Northern Italy, by monitoring the vegetative and reproductive traits of the orchid populations growing both in the protected sites comprising the Natura 2000 network, and in non-protected sites. We also monitored the level of environmental threat to orchid vitality. The early-flowering deceptive species (Ophrys sphegodes and Anacamptis morio) exhibited high vegetative vitality and experienced similar levels of environmental threat in the protected and non-protected areas. However, their reproductive success was strongly jeopardized, probably by a failed pollination that impeded the fruit set. The late-flowering, partially or totally rewarding species (Anacamptis pyramidalis and Anacamptis coriophora) were more strongly impacted by spring mowing and ungulate herbivory and alien species. Only for A. coriophora were the herbivory and alien species invasions lower at the protected vs. non-protected sites, which ensured a higher population vitality at the protected sites. We conclude that the environmental protection in our study area is ineffective for preserving orchids without targeted actions against specific environmental threats.

Pollination strategies of deceptive orchids – a review

Orchids can be classified in terms of their pollination into rewarding species, which produce nectar in their flowers that serves as a reward for pollinators and deceptive species, whose flowers do not contain nectar and save energy for other purposes. This paper concentrates on the latter. Deceptive orchids attempt to deceive their pollinators by being similar to some non-orchid rewarding species, but not providing a reward. Each of these strategies has its advantages and disadvantages in terms of their effect on future fitness of a plant and/or population and subsequently its survival as a species. In summary, the literature indicates that deceptive strategies may lower reproductive success, but may be compensated for in that they cost less in terms of energy. This should be taken into consideration when developing management strategies for these species, which is often done by non-orchid specialists. This article is intended for such non-specialist audience and includes a description of the main types of deceptive strategies used by orchids, as well as examples of the most typical species.

Batesian mimicry or general food deception? An evolutionary game between plants for pollinator services

Floral food deception is a well-known phenomenon which is not thoroughly understood. Particularly, it is unclear what drives a plant towards Batesian mimicry or towards generalized food deception. We analysed the evolutionary game between a Model species with nectar-secreting flowers and a Deceiver species that provides no nectar who share pollinators for reproduction. We focused our analysis on the effect of similarity of floral signals between participating plants and on costs of nectar production. We defined payoffs in the game between Models and Deceivers as the stationary visitation frequencies to participating species with different signal similarities and nectar costs. Therefore, fitness payoff of each strategy was a product of complex interactions between plant species composing the community and the pollinators visiting them. Our model provides a unified framework in which consequences of Model species interaction with different deception modes can be compared. Our findings suggest that plant-pollinator systems, like other mutualistic systems, are prone to exploitation, and that exploitation may persist at a large range of conditions. We showed that floral similarity, and thus, pollinators’ ability to discriminate between Model and deceptive species, governs the stability of Batesian mimicry, while pollinator switching and sampling behaviour enables the persistence of general food deception.

Phenotype-fitness relationships and pollen-transfer efficiency of five orchid species with different pollination strategies.

Deceptive pollination, a fascinating mechanism that independently originated in several plant families for benefiting from pollinators without providing any reward, is particularly widespread among orchids. Pollination efficiency is crucial in orchids due to the aggregated pollen in a pollinarium, which facilitates pollen transfer and promotes cross-pollination as pollinators leave after being deceived. In this study, we compiled data on reproductive ecology from five orchid species with different pollination strategies: three deceptive-strategy species (shelter imitation, food deception, sexual deception), one nectar-rewarding species, and one shelter-imitation but spontaneously selfing species. We aimed to compare the reproductive success (female fitness: fruit set; male fitness: pollinarium removal) and pollination efficiency of species representing these strategies. We also investigated pollen limitation and inbreeding depression among the pollination strategies. Male and female fitness were strongly correlated in all species but the spontaneously selfing species, which had high fruit set and low pollinarium removal. As expected, pollination efficiency was highest for the rewarding species and the sexually deceptive species. Rewarding species had no pollen limitation but did have high cumulative inbreeding depression; deceptive species had high pollen limitation and moderate inbreeding depression; and spontaneously selfing species did not have pollen limitation or inbreeding depression. Pollinator response to deception is critical to maintain reproductive success and avoid inbreeding in orchid species with non-rewarding pollination strategies. Our findings contribute to a better understanding of the trade-offs associated with different pollination strategies in orchids and highlight the importance of pollination efficiency in orchids due to the pollinarium.

The Floral Signals of the Inconspicuous Orchid Malaxis monophyllos: How to Lure Small Pollinators in an Abundant Environment.

Simple SummaryMalaxis monophyllos is an ephemeral orchid with very small, greenish flowers, whose pollination system remains vague. Therefore, the authors aimed to identify the flower’s features, including its anatomical micro and ultrastructure as well as scent biochemistry, which are involved in attracting pollinators. In this paper, the authors established the variety of emissions of M. monophyllos volatile compounds, with a high proportion of aldehydes and aliphatic alcohols, listed as chemicals that induce a pronounced reaction in Diptera. Second, the entire M. monophyllos labellum exhibits metabolic and secretory activity, which can be related to both emission of volatiles and visual attractants but also to the nutritional reward for pollinators. All these flower features indicated that its pollination system is dedicated to dipterans, with few signaling modalities corresponding to deceptive species (brood site and food decoy) but also referring to rewarding ones (nutritional secretion, fungus/microbe reward). This research reveals a few new issues in M. monophyllos pollination biology that provides new scientific areas for in-depth insights in the future.Many orchid species have evolved complex floral signals to ensure pollination efficiency. Here, the authors combined analyses of anatomical flower structure with analyses of the volatile composition and flower-visiting insects’ behaviour, as well as characterised features that can attract pollinators of the inconspicuous orchid Malaxis monophyllos. During field observations, the authors found that only small Diptera (e.g., mosquitos, drosophilids, fungus gnats) visit and are interested in the flowers of M. monophyllos, which was reflected in the characterised flower features that combine well with the pollination system, which engages dipterans. Analyses of the M. monophyllos floral scent revealed substantial concentrations of aliphatic compounds, e.g., 1-octen-3-ol and 1-octanol, which condition the mushroom-like scent and a substantial fraction of alkanes, some of which have been previously described as sex mimicry and aggregation pheromones in orchids’ deceptive systems. The labellum anatomical structure exhibits a highly diverse cell cuticle surface and pronounced metabolic and secretory activity of the epidermal and subepidermal cells from all parts of the labellum. Moreover, our study provides evidence for the subsequent decoys of M. monophyllos flowers, including visual signals, such as raphides located on the labellum margin and the rewarding ones connected with lipid secretion limited to the area behind the column. Taking an integrative approach to studying M. monophyllos pollination biology, the authors provide new insight into its previously vague pollination strategies and provide evidence for complex floral signal operation in luring potential pollinators. The synergistic effect of M. monophyllos flowers’ volatile and visual signals, together with additional rewarding for nectar/fungus/microbe-feeding pollinators, requires further detailed investigation that will be invaluable in explaining the evolution of Diptera-specific pollination systems in orchids.

Reproductive character displacement allows two sexually deceptive orchids to coexist and attract the same specific pollinator

An increased divergence in characters between species in secondary contact can be shaped by selection against competition for a common resource (ecological character displacement, ECD) or against maladapted hybridization (reproductive character displacement, RCD). These selective pressures can act between incipient species (reinforcement) or well-separated species that already completed the speciation process, but that can still hybridize and produce maladapted hybrids. Here, we investigated two well-separated sexually deceptive orchid species that, unusually, share their specific pollinator. Sympatric individuals of these species are more divergent than allopatric ones in floral characters involved in a mechanical isolating barrier, a pattern suggestive of RCD. To experimentally test this scenario, we built an artificial sympatric population with allopatric individuals. We measured flower characters, genotyped the offspring in natural and artificial sympatry and estimated fertility of hybrids. Different from naturally sympatric individuals, allopatric individuals in artificial sympatry hybridized widely. Hybrids showed lower pollination success and seed viability than parentals. Character displacement did not affect plant pollination success. These findings suggest that RCD evolved between these species to avoid hybridization and that selection on reinforcement may be very strong even in plants with highly specialized pollination.

Caladenia multiplex (Orchidaceae), a new, sexually deceptive species from the south-west of Western Australia

<i>Caladenia multiplex</i> (Orchidaceae), a new, sexually deceptive species from the south-west of Western Australia

What pollinators see does not match what they smell: Absence of color-fragrance association in the deceptive orchid Ionopsis utricularioides

Many deceptive orchids present variation in floral color and fragrance. This might be advantageous for the plant, as it can disturb the associative avoidance learning of pollinators, promoting more visits to the flowers. Some studies have shown that color and fragrance can be correlated in polymorphic deceptive orchids, but these studies employed color traits based on the human visual system and not the visual perception of pollinators. Thus, we investigated the composition of the floral fragrance of Ionopsis utricularioides (Sw.) Lindl., a polymorphic deceptive orchid, and analyzed possible correlations with the floral color as seen by bees, Apis mellifera L. and Melipona quadrifasciata Lepeletier, using the color hexagon model. We found high color and fragrance intraspecific variation, as expected for deceptive species. However, we found no color-fragrance association in individuals, either by comparing fragrance profiles with the color variable saturation or by comparing them with the placement of individuals in the color hexagon for both bee species. This lack of correlation contradicts the biochemical pathway hypothesis, which proposes that associations between floral color and scent in polymorphic flowers arise from shared biochemical pathways. However, a complete absence of correlation between floral signals is consistent with selection arising through pollinator cognitive ecology. Lack of correlation would increase the floral variability perceived by bees, given their multimodal learning, and this variability could disrupt avoidance learning of deceptive flowers, thus enhancing the efficacy of the plant's deceptive pollination mechanism.

Rotating Arrays of Orchid Flowers: A Simple and Effective Method for Studying Pollination in Food Deceptive Plants

Floral deception has been observed in several genera in angiosperms, but is most common in the Orchidaceae. Pollination mechanisms in food deceptive plants are often difficult to assess, as visitation frequency by insects requires numerous hours of field observations to ascertain. Here, for the first time, we describe in detail and validate a simple and effective method that extends previous approaches to increase the effectiveness of pollination studies of food deceptive orchids. We used an orchid of southwest Australia, Diuris brumalis (Orchidaceae), that visually mimics model plants belonging to the genus Daviesia (Faboideae). Arrays of orchid flowers were placed and moved systematically in proximity to model plants, resulting in rapid attraction of the pollinators of D. brumalis. We compared pollinaria removal (as an indicator of pollination success) in naturally growing orchids with pollinaria removal in arrays of orchid flowers in the same sites. We showed that the proposed method greatly enhances pollinator attractiveness in food deceptive systems with very low pollination rates, and we compared its efficiency with other similar methods. The approach can be used for observing pollinator behavioural patterns and confirming effective pollinators for food deceptive species with low insect visitation rates.

Modelling sexually deceptive orchid species distributions under future climates: the importance of plant\u2013pollinator interactions

Biotic interactions play an important role in species distribution models, whose ignorance may cause an overestimation of species' potential distributions. Species of the family Orchidaceae are almost totally dependent on mycorrhizal symbionts and pollinators, with sexually deceptive orchids being often highly specialized, and thus the interactions with their pollinators are expected to strongly affect distribution predictions. We used Maxent algorithm to explore the extent of current and future habitat suitability for two Greek endemic sexually deceptive orchids (Ophrys argolica and Ophrys delphinensis) in relation to the potential distribution of their unique pollinator (Anthophora plagiata). Twelve climate change scenarios were used to predict future distributions. Results indicated that the most important factors determining potential distribution were precipitation seasonality for O. argolica and geological substrate for O. delphinensis. The current potential distribution of the two orchids was almost of the same extent but spatially different, without accounting for their interaction with A. plagiata. When the interaction was included in the models, their potentially suitable area decreased for both species. Under future climatic conditions, the effects of the orchid-pollinator interaction were more intense. Specifically, O. argolica was restricted in specific areas of southern Greece, whereas O. delphinensis was expected to become extinct. Our findings highlighted the significant role of plant–pollinator interactions in species distribution models. Failing to study such interactions might expose plant species to serious conservation issues.

A specialised pollination system using nectar-seeking thynnine wasps in Caladenia nobilis (Orchidaceae).

Caladenia is a diverse Australian genus that is exceptional among orchids in having both species pollinated by food-seeking and sexually deceived insects. Here, we investigated the pollination of Caladenia nobilis, a species predicted to be food-deceptive due to its large, cream-coloured and apparently nectarless flowers. Pollinator observations were made using experimental clumps of flowers. Measurements of floral colour were undertaken with a spectrometer, nectar was tested using GC-MS, and reproductive success was quantified for 2years. While C.nobilis attracted nine species of insect, only males of the thynnine wasp Rhagigaster discrepans exhibited the correct size and behaviour to remove and deposit pollen. Male R.discrepans attempted to feed from the surface of the labellum, often crawling to multiple flowers, but showed no evidence of sexual attraction. Most flowers produced little or no nectar, although some may provide enough sucrose to act as a meagre reward to pollinators. Floral colouration was similar to a related Caladenia species pollinated by sexual deception, although the sexually deceptive species had a dull-red labellum. Reproductive success was generally low and highly variable between sites and years. In addition to most visitors being of inappropriate size for pollinia removal, the lack of response to the orchid by several co-occurring species of thynnine wasp suggests filtering of potential pollinators at the attraction phase. Our discovery of a pollination strategy that may be intermediate between food deception and food reward raises the question, how many putatively rewardless orchids actually produce meagre amounts of nectar?

The demography of terrestrial orchids: life history, population dynamics and conservation

Abstract Terrestrial orchid life-cycles are complex and dependent on pollinators and mycorrhizal associates. Worldwide, orchid populations are declining because of urbanization, atmospheric nitrogen deposition and climate change. To advance understanding of the factors determining orchid population viability, we review knowledge about orchid demography, life histories and population dynamics. Orchids can produce thousands of seeds, although few survive to reach maturity, with mortality rates declining from juvenile to adult life states. Flowering and fruiting rates vary widely between years, and many populations, especially of deceptive species, are pollen- and seed-limited. Many species have long lifespans and periods of vegetative dormancy and exhibit costs associated with reproduction, sprouting, vegetative dormancy, growth and size. Population growth rates range from 0.50–2.92 (mean: 0.983 ± 0.026). Although vital rates can fluctuate widely between years and be strongly correlated, these correlations have little impact on population dynamics. Variation in spatial density of fungi and microsite quality, limited dispersal and competition generate density dependence in vital rates. Future research should elucidate the roles of biotic and abiotic factors on population dynamics to underpin effective management for conservation. Understanding the impact of idiosyncratic individual plant behaviour on population dynamics will also improve demographic parameter estimation, including population growth rate and net reproductive rate.

Do local conspecific density and floral display size influence fruit set via pollinator visitation in Orchis militaris?

Plant density varies naturally, from isolated plants to clumped individuals, and this can influence pollinator foraging behaviour and plant reproductive success. In addition, the effect of conspecific density on reproduction may depend on the pollination system, and deceptive species differ from rewarding ones in this regard, a high density being often associated with low fruit set in deceptive plants. In our study, we aimed to determine how local conspecific density and floral display size (i.e. number of flowers per plant) affect fruit set in a deceptive orchid (Orchis militaris) through changes in pollinator visitation. We measured fruit set in a natural population and recorded pollinator abundance and foraging behaviour within plots of different O. militaris densities. Detailed data were recorded for the most abundant potential pollinators of O. militaris, i.e. solitary bees. Floral display size was negatively correlated to fruit set in medium‐density plots, but uncorrelated in low‐ and high‐density plots. Plot density had no effect on solitary bee abundance and visitation, which may be due to low pollinator abundance within the study site. The proportion of visited flowers per inflorescence was negatively influenced by floral display size, which is in line with previous studies. In addition, solitary bees spent decreasing time in successive flowers within an inflorescence, and the time spent per flower was negatively affected by ambient temperature. Our results suggest that pollinator behaviour during visitation is poorly linked to pollen deposition and reproductive success in O. militaris.

Variability in space and time: contrasting fruit distribution patterns in the deceptive orchid Orchis militaris

In angiosperms, a decrease in fruit production towards the apex of individual inflorescences is usually observed. Orchids are thought to be primarily pollination-limited species, and non-uniform pollination could cause this decrease pattern in several species. Fruit production was investigated in relation to flower position and floral display size in Orchis militaris (Orchidaceae), a deceptive species. Over 2years, eight populations of O.militaris were studied and fruit position along the inflorescence was recorded. Generalised linear models were performed to examine the effect of population, year, flower position and floral display size on fruit production. The dominant pattern was characterised by a higher fruit set in the middle part of the inflorescence (parabolic pattern). A non-directional pattern of fruit production was also detected in some populations. Within a given population, patterns were generally consistent among years. In one of the two study years and in one of the eight populations specifically, the proximal-to-distal decrease in fruit production was dramatic in plants with a large floral display but weak or absent in small displays. Our study demonstrates the intraspecific diversity of fruit distribution patterns in O.militaris. Non-uniform pollination along the inflorescence is likely to be responsible for the parabolic pattern, while irregular visitation could explain the non-directional pattern of fruit production. Pattern variation among years and between populations could arise from spatiotemporal variation in pollinator assemblages. Resource competition effects could explain the interaction effect between display size and flower position.

An experimental evaluation of traits that influence the sexual behaviour of pollinators in sexually deceptive orchids.

Pollination by sexual deception of male insects is perhaps one of the most remarkable cases of mimicry in the plant kingdom. However, understanding the influence of floral traits on pollinator behaviour in sexually deceptive plants is challenging, due to the risk of confounding changes in floral odour when manipulating morphology. Here, we investigated the floral traits influencing the sexual response of male Zaspilothynnus nigripes (Tiphiidae) wasps, a pollinator of two distantly related sexually deceptive orchids with contrasting floral architecture, Caladenia pectinata and Drakaea livida. In D.livida, the chemical sexual attractant is emitted from the labellum, whereas in C.pectinata, it is produced from the distal sepal tips, allowing manipulative experiments. When controlling for visual cues, there was no difference in long-distance attraction, although the floral odour of D.livida induced copulation more frequently than that of C.pectinata. The role of colour in pollinator sexual attraction was equivocal, indicating that colour may not be a strong constraint on the initial evolution of sexual deception. The frequency of wasp visitors landing on C.pectinata decreased when the amount of floral odour was reduced, but attempted copulation rates were enhanced when the source of floral odour was associated with the labellum. These latter variables may represent axes of selection that operate across many sexually deceptive species. Nonetheless, the observed variation in floral traits suggests flexibility among species in how sexual deception can be achieved.

Unidirectional transitions in nectar gain and loss suggest food deception is a stable evolutionary strategy in Epidendrum (Orchidaceae): insights from anatomical and molecular evidence

BackgroundNectar gain and loss are important flower transitions observed in angiosperms, and are particularly common in orchids. To understand such transitions, the availability of detailed anatomical data and species-level phylogenies are crucial. We investigated the evolution of food deception in Epidendrum, one of the largest orchid genera, using genus phylogeny to map transitions between nectar gain and loss among different clades. Associations between anatomical and histochemical changes and nectar gain and loss were examined using fresh material available from 27 species. The evolution of nectar presence/absence in Epidendrum species was investigated in a phylogenetic framework of 47 species, using one nuclear and five plastid DNA regions available from GenBank and sequenced in this study.ResultsThe presence or absence of nectar was strongly associated with changes in the inner epidermal tissues of nectaries. Nectar-secreting species have unornamented epidermal tissue, in contrast to the unicellular trichomes found on the epidermis of food deceptive species. Bayesian tests confirmed that transitions occurred preferentially from nectar presence to nectar absence across the Epidendrum phylogeny. In addition, independent nectar loss events were found across the phylogeny, suggesting a lack of constraint for these transitions.ConclusionsOrnamented nectaries may play an important role in the deceptive pollination strategy by secreting volatile organic compounds and providing tactile stimuli to pollinators. The recurrent and apparently irreversible pattern of nectar loss in Epidendrum suggests that food deception may constitute an alternative evolutionarily stable strategy, as observed in other orchid groups.

Incomplete synchrony of inflorescence scent and temperature patterns in Arum maculatum L. (Araceae)

In many Araceae both scent and heat production are known to temporally vary throughout anthesis, and in several species strong scents are released for pollinator attraction when thermogenesis is also strong. However, it is not known whether the temporal patterns of both scent emission and temperature are strictly synchronous and, for example, reach their maxima at the same time. We studied Arum maculatum, a brood-site deceptive species attracting its moth fly pollinators with strong fetid scents, to study temporal patterns in scent emission and temperature during anthesis. Inflorescence scents were collected and analysed by dynamic headspace and gas chromatography-mass spectrometry (GC-MS) or by proton-transfer-reaction-time-of-flight mass spectrometry (PTR-TOFMS), and the temperature of the appendix, which is the heating osmophore during pollinator attraction, was recorded by a thermocouple. We overall found that scent emission and temperature patterns were strongly correlated. However, in none of the seven studied individuals was the highest amount of scent released at times with the maximum temperature difference. Thus, patterns of scent emission and temperature are somewhat asynchronous suggesting that high scent emission rates and temporal scent patterns in plants with thermogenesis cannot be solely explained by temperature patterns. This calls for more in-depth studies to better understand the interplay between scent emission and thermogenesis.

Effects of plant and pollinator traits on the maintenance of a food deceptive species within a plant community

Model–mimic plant systems are well known. However, the conditions promoting the existence of such systems are still an enigma. We suggest that by focusing on floral similarity between model and mimic, reward levels offered by models, and pollinators’ ability to adjust foraging accordingly, the conditions can be better understood. Using spatially‐explicit modelling, we examined trait combinations that lead to the survival of deceptive species under a large range of mimic strategies, from Batesian mimicry to general food deception. Unlike previous models studying such systems, we examined model–mimic interactions in the presence of a third, dissimilar species, thus generating a more realistic scenario where pollinators may avoid the model–mimic system altogether. Results showed that overall survival and abundance of species in food deceptive systems depend on the relative reward provided by the participating species and the potential alternatives available. Specifically, the success of a mimic in a Batesian mimicry system depends on high levels of reward provided by its model species relative to potential alternatives in the flower community. On the other hand, the success of a mimic in a general food deception system was higher when the reward offered was lower. Our study suggests that the ability of pollinators to utilize their experience as part of decision‐making is highly relevant in promoting mimic survival, thus shedding light on the conditions under which food deception is expected.

When it pays to cheat: Examining how generalized food deception increases male and female fitness in a terrestrial orchid.

BackgroundExperimental manipulations of floral nectar in food deceptive species can reveal insights into the evolutionary consequences of the deceptive strategy. When coupled to pollen tracking, the effects of the deceptive pollination syndrome on both male and female reproductive success may be quantified. Attraction of pollinators in deceit-pollinated species often relies on producing a conspicuous floral display which may increase visibility to pollinators, but in-turn may increase within plant selfing.MethodologyTo understand the role of deception in Orchidaceae reproduction we studied Cypripedium candidum. All species of the Cypripedium genus employ a generalized food deceptive pollination strategy and have been suggested as a model system for the study of pollinator deception. We conducted a nectar addition experiment that randomly assigned the four plants closest to a transect point to receive one of four histochemical dyes. Two individuals selected for nectar addition in each of altogether 25 blocks received 2μl of 25% sucrose solution in the labellum of each flower, while two others received no artificial nectar. Number of fruits produced, fruit mass and fruit abortion were scored at the end of the four-month experiment.ResultsNectar addition increased (p<0.0001) self-pollination and pollen discounting by nearly 3x, while plants not receiving nectar had greater (p<0.0001) numbers of non-self pollinia deposited and lower rates of pollen discounting. There was a non-significant (p = 0.0645) trend for deceptive plants to set more fruit, while presence of nectar did not affect pollen export.ConclusionsThis study demonstrates the adaptive advantages of food deception by showing a concurrent reduction in particular male and female functions when a food reward is restored to a deceptive flower. We found generalized food deception to not only decrease inbreeding depression in the system, but concurrently have no effect on pollinator attraction and fruit set when compared with rewarding flowers.

Telipogon peruvianus (Orchidaceae) Flowers Elicit Pre-Mating Behaviour in Eudejeania (Tachinidae) Males for Pollination.

Several neotropical orchid genera have been proposed as being sexually deceptive; however, this has been carefully tested in only a few cases. The genus Telipogon has long been assumed to be pollinated by male tachinid flies during pseudocopulatory events but no detailed confirmatory reports are available. Here, we have used an array of methods to elucidate the pollination mechanism in Telipogon peruvianus. The species presents flowers that have a mean floral longevity of 33 days and that are self-compatible, although spontaneous self-pollination does not occur. The flowers attract males of four tachinid species but only the males of an undescribed Eudejeania (Eudejeania aff. browni; Tachinidae) species are specific pollinators. Males visit the flowers during the first few hours of the day and the pollination success is very high (42% in one patch) compared with other sexually deceptive species. Female-seeking males are attracted to the flowers but do not attempt copulation with the flowers, as is usually described in sexually deceptive species. Nevertheless, morphological analysis and behavioural tests have shown an imperfect mimicry between flowers and females suggesting that the attractant stimulus is not based only on visual cues, as long thought. Challenging previous conclusions, our chemical analysis has confirmed that flowers of Telipogon release volatile compounds; however, the role of these volatiles in pollinator behaviour remains to be established. Pollinator behaviour and histological analyses indicate that Telipogon flowers possess scent-producing structures throughout the corolla. Our study provides the first confirmed case of (i) a sexually deceptive species in the Onciidinae, (ii) pollination by pre-copulatory behaviour and (iii) pollination by sexual deception involving tachinid flies.