Myophily is pollination carried out by flies, and it accounts for a surprisingly large share of the pollination happening in the world’s ecosystems. The term comes from the Greek words for “fly” and “love,” and it encompasses a wide range of interactions between flowering plants and the order Diptera, from tiny midges visiting cacao blossoms to large hoverflies working berry crops. While bees get most of the public attention, flies are the second most important group of pollinators globally, and in some environments they are the dominant one.
How Myophily Differs From Sapromyophily
Not all fly pollination works the same way. Researchers distinguish between myophily in the stricter sense and a related syndrome called sapromyophily, and the difference matters because the plants involved use completely different strategies to attract their pollinators. In myophily, flowers offer genuine rewards. They produce nectar, and the flies that visit them are coming to feed. The relationship is cooperative in the way most people imagine pollination to be: the plant gets pollen moved, the fly gets a meal.
Sapromyophily, by contrast, is a con job. Sapromyophilous flowers produce no nectar. Instead, they mimic rotting flesh, dung, or decaying organic matter to lure flies that normally lay their eggs on those substances. The flies arrive expecting a place to deposit eggs or a carcass to feed on, and they leave dusted with pollen but having gained nothing. Carrion flowers like those in the genus Rafflesia and the famous corpse flower (Amorphophallus titanum) are the best-known examples. The chemical mimicry involved is remarkably precise: gas chromatography has shown that the volatile compounds these flowers release closely match those produced by dead animals in early decomposition, particularly sulfur compounds like dimethyl disulfide and dimethyl trisulfide that originate from the breakdown of sulfur-containing amino acids in protein.1Current Biology. Carrion flowers Fly antennae are tuned to detect these compounds, and flies can be drawn to them even without any visual cues.
The distinction between the two syndromes shows up in the flowers’ physical anatomy, not just their chemistry. In orchids of the subtribe Pleurothallidinae, for example, myophilous species that offer nectar tend to have unicellular trichomes on the labellum (the “lip” of the orchid flower), while sapromyophilous species that rely on deception lack nectaries entirely and instead have specialized scent-producing glands called osmophores on their labellum.2PubMed. Floral glands in myophilous and sapromyophilous species of Pleurothallidinae (Epidendroideae, Orchidaceae)-osmophores, nectaries, and a unique sticky gland In evolutionary terms, the sticky-exudate glands found in sapromyophilous lineages appear to be a newer innovation compared to the nectar-producing structures in myophilous ones.3Flora. Floral gland diversity in Pleurothallidinae (Epidendroideae–Orchidaceae)
Which Flies Pollinate, and How Many
The sheer diversity of fly pollinators is one of the things that makes myophily so hard to generalize about. Diptera is an enormous order, and the flies involved in pollination range from large, conspicuous species that look and behave a bit like bees to tiny creatures barely visible to the naked eye. Among the more recognizable fly pollinators are hoverflies (Syrphidae), bee flies (Bombyliidae), blowflies (Calliphoridae), house fly relatives (Muscidae), tachinid flies (Tachinidae), and flower flies in the family Anthomyiidae. On the smaller end, midges in families like Ceratopogonidae, Chironomidae, and Mycetophilidae are important pollinators that most people would never notice.4Conservation Ecology. North American Dipteran Pollinators: Assessing Their Value and Conservation Status
These flies vary enormously in how effective they are as pollinators. Some carry large amounts of pollen and spend significant time foraging on flowers. Others are incidental visitors that pick up a few grains by accident. Proboscis length alone spans a huge range, from a couple of millimeters in many common flies up to about 70 mm in certain South African tangle-veined flies (family Nemestrinidae) that have coevolved with deep-tubed flowers.5Conservation Ecology. North American Dipteran Pollinators: Assessing Their Value and Conservation Status That range of mouthpart morphology means flies collectively can access nectar across a far wider spectrum of flower shapes than any single pollinator group.
Traps, Tricks, and Visual Lures
Some myophilous plants do not simply wait for flies to wander in. Certain species have evolved physical trapping mechanisms that temporarily detain their pollinators to maximize pollen transfer. Trap flowers in families like Aristolochiaceae and Araceae use inward-pointing trichomes (hair-like structures) to funnel flies into a chamber and prevent them from leaving until the flower’s pollen is ready. Features like a density gradient of trichomes toward the flower’s interior, unidirectional orientation of the hairs, and waxy coatings on surfaces all contribute to keeping the fly inside long enough for pollination to occur.6Functional Ecology. Sex, flies and flower trap: Trapping trichomes and their function in pollination The fly eventually escapes, often through a separate exit that forces it past pollen-bearing structures on its way out.
Visual cues also play a role. Sapromyophilous flowers often mimic the dark reds and purples of decaying meat, sometimes with translucent patches that create the illusion of depth or texture. But in straightforward myophily, flower color and shape work more like conventional advertising. Hoverflies, for instance, show clear color preferences. Naive hoverflies of the species Eristalis tenax strongly prefer yellow flowers, though this preference weakens and even reverses with experience, shifting toward white flowers after repeated foraging bouts.7Journal of Experimental Biology. Learning to be unfaithful – preferences and flower constancy of Eristalis tenax (Syrphidae) decrease with experience This flexibility means that fly-pollinated plants face a less predictable audience than bee-pollinated ones: flies are less “faithful” to a single flower type, which can be an advantage for plants growing in mixed communities where strict flower constancy by pollinators could leave some species unvisited.
The Carrion Flower Chemistry Up Close
The chemical side of sapromyophily deserves a closer look because it illustrates just how precisely natural selection can calibrate a deception. Rafflesia cantleyi, one of the giant parasitic flowers of Southeast Asia, produces a floral scent dominated by dimethyl disulfide and dimethyl trisulfide. In flight-tunnel experiments, only female blowflies of a specific species (Chrysomya chani) were attracted to these compounds, suggesting that the flower is selectively targeting flies that are looking for a place to lay eggs on carrion.8PubMed. Pollinator specialization in the enigmatic Rafflesia cantleyi: A true carrion flower with species-specific and sex-biased blow fly pollinators The relative ratios of the sulfur compounds appear to matter as much as their presence, meaning the flower is not just broadcasting a generic “rotting meat” signal but tuning the blend to attract a particular pollinator species and sex.
This level of specificity is unusual. Most fly-pollinated systems are relatively generalized, with many fly species visiting a given flower. The Rafflesia case is an extreme that shows how far the mimicry can be pushed when there is strong selective pressure for specialization.
Long Tongues and Deep Tubes
One of the most elegant examples of fly-plant coevolution involves long-proboscid flies in southern Africa. A tangle-veined fly, Prosoeca ganglbaueri, pollinates the plant Zaluzianskya microsiphon, and across both species’ geographic ranges, the length of the fly’s tongue and the depth of the flower’s corolla tube vary together from site to site. At locations where the flies have longer tongues, the flowers have deeper tubes, and vice versa. This correlation holds even when researchers account for altitude, latitude, and body size, and the match between tongue and tube length directly affects how well the plant reproduces.9Evolution. THE GEOGRAPHICAL MOSAIC OF COEVOLUTION IN A PLANT–POLLINATOR MUTUALISM
This is not just a curiosity of one pair. Entire guilds of fly-pollinated plants at the same site converge on similar flower depths that match the local fly’s tongue length. Plants that offer real nectar rewards seem to drive the coevolution with the fly, while rarer, non-rewarding species that do not provide nectar track the same tongue length through one-sided adaptation, essentially hitchhiking on the relationship between the fly and its primary food plants.10PubMed. Geographical covariation and local convergence of flower depth in a guild of fly-pollinated plants Modeling work suggests that competition for pollinators among plant species can be the trigger for this kind of escalation: when two plant species compete for the same pollinator, variability in tube depth can drive the pollinators to diverge in tongue length, and once the pollinators diverge, the plants follow.11PLoS ONE. Resource Competition Triggers the Co-Evolution of Long Tongues and Deep Corolla Tubes
Flies Take Over in Cold and High Places
The ecological importance of myophily becomes most obvious where bees struggle. In arctic tundra, high-altitude alpine meadows, and cool maritime climates, flies often become the primary or even the only pollinators available. This is partly because many fly species are more cold-tolerant than bees and can remain active at lower temperatures and in windier conditions.
Studies in the European Alps have found striking altitude-dependent shifts in pollinator communities. While bees, beetles, and butterflies all declined in both species richness and visitation frequency above about 1,400 meters, flies actually increased, peaking in diversity and abundance around 2,100 meters. Above roughly 1,500 meters elevation, flies became the dominant flower visitors at every study site.12PubMed Central. Altitudinal, temporal and trophic partitioning of flower-visitors in Alpine communities In many arctic and subarctic environments, flies are so dominant that their contribution is not just supplementary but essential for plant reproduction.13Conservation Ecology. North American Dipteran Pollinators: Assessing Their Value and Conservation Status
This has practical implications as climate change reshapes mountain ecosystems. If bee ranges shift upward and overlap more with fly-dominated zones, the dynamics of alpine plant pollination could change in ways that are hard to predict. The alpine data also suggests that anywhere bee populations are stressed or declining, flies represent a functional backstop that may already be doing more pollination work than we realize.
How Flies Carry Pollen Compared to Bees
One common assumption is that flies are sloppy, inefficient pollinators compared to bees. The reality is more nuanced. Bees generally carry larger pollen loads, which makes sense given that they are actively collecting pollen to feed their larvae. On oilseed rape, for example, bees in families like Andrenidae and bumblebees carried the heaviest median pollen loads. But several fly families carried substantial amounts too: dance flies (Empididae), march flies (Bibionidae), flesh flies (Sarcophagidae), and hoverflies (Syrphidae) all carried hundreds to over a thousand pollen grains per individual.14Basic and Applied Ecology. Shared traits make flies and bees effective pollinators of oilseed rape (Brassica napus L.)
Where flies sometimes outperform bees is in pollen transport distance. In a study that tracked how far different pollinator taxa moved pollen across a fragmented landscape, soldier flies (Stratiomyidae) and hoverflies carried pollen up to 400 meters from the source plant, farther than either of the bee families studied.15Diversity and Distributions. Pollen transport differs among bees and flies in a human‐modified landscape This long-distance movement matters for maintaining genetic connectivity between isolated plant populations, especially in agricultural landscapes where habitat patches are separated by fields and roads.
The reason flies tend to move pollen farther may relate to their foraging behavior. Bees, especially social species, tend to work patches intensively before moving on. Many flies are less systematic: they flit between plants more erratically, visiting a wider variety of species in a single foraging bout. This “unfaithfulness” is a disadvantage from the plant’s perspective when it comes to ensuring pollen lands on the right species, but it can be an advantage for gene flow across distance.
Cacao, Berries, and Mangoes
The agricultural significance of myophily is most obvious in cacao, the source of chocolate. Cacao flowers are tiny, complex, and accessible mainly to very small insects. Their primary pollinators are ceratopogonid midges, and the interaction is facilitated by the volatile scent blend the flowers release, which triggers a generalized attraction response across multiple midge species.16PubMed. Floral Odors and the Interaction between Pollinating Ceratopogonid Midges and Cacao Without these midges, cacao yields collapse. It is one of the clearest cases of a major global crop being entirely dependent on fly pollination.
But the agricultural story is expanding beyond cacao. Field trials on commercial berry farms in Australia have shown that managed hoverflies (Eristalis tenax) can produce fruit comparable in weight and marketability to fruit pollinated by honeybees or native stingless bees. In full-scale commercial polytunnels, hoverflies matched open (mainly bee) pollination during spring and actually outperformed it under the cooler, more variable conditions of winter.17Agriculture, Ecosystems & Environment. Managed fly pollinators ensure berry crop yields under variable weather conditions This climate resilience is a selling point: hoverflies keep working in weather that grounds bees.
In mango production under greenhouse conditions, deploying hoverflies (Eristalis aeneus) at medium to high densities improved yields and fruit quality compared to bumblebee pollination or no-insect controls. The economic gains ranged from modest to dramatic depending on the growing season.18Scientia Horticulturae. Hoverfly pollination enhances yield and fruit quality in mango under protected cultivation These results are prompting some growers to consider managed fly populations as a complement or even an alternative to managed bee colonies, especially in protected cropping systems where bee behavior can be unpredictable.
Why Flies Get Overlooked
Given all of this, it is reasonable to ask why myophily gets so little attention compared to bee pollination. Part of the answer is cultural. Bees are charismatic, familiar, and associated with honey and hard work. Flies are associated with garbage and disease. Conservation messaging has understandably leaned heavily on the “save the bees” narrative, which has been enormously successful at generating public concern but has left other pollinator groups in the shadows.
There are also genuine scientific gaps. Taxonomic expertise for many fly families is thin, meaning researchers often cannot identify the fly species visiting a flower, which makes it hard to study the interactions in detail. A review of pollinator conservation in urban settings noted that understanding the role and life cycles of fly pollinators is vital but that significant research gaps hinder efforts to use groups like hoverflies for their potential dual benefits as both pollinators and biological pest controllers.19Oxford Academic. Opportunities for and Impediments to Pollinator Conservation in Urban Settings: A Review Hoverfly larvae, for instance, include many species that feed on aphids, meaning the same insect could be delivering pollination services as an adult while providing pest control as a larva. But research on this dual role is sparse.
Flies in Cities
Urban landscapes might seem inhospitable to pollinators, but flies appear to respond differently to urbanization than bees do. An analysis of pollinator occurrence across urban landscapes found that native hoverfly diversity was positively associated with the amount of natural greenspace, meaning parks, remnant bushland, and other semi-natural habitats within the urban matrix.20PubMed Central. Urban landscapes with more natural greenspace support higher pollinator diversity Developed greenspace like manicured lawns and sports fields showed no such association for any pollinator group. For bumblebees, the picture was mixed: on average there was no association with natural greenspace, though several at-risk species did benefit from it.
The implication for urban planners is that preserving pockets of wilder, more natural vegetation in cities disproportionately benefits fly pollinators. Since many hoverfly species can tolerate conditions that stress bees, such as cooler temperatures, wind, and fragmented habitat, they may be among the more resilient pollinator groups in urban environments. But that resilience is not unlimited, and it depends on the availability of suitable habitat for breeding and larval development, not just adult foraging.
When Fly Pollination Beats Bee Pollination
There is no universal answer to whether flies or bees are “better” pollinators, because the question depends entirely on context. But there are several situations where myophily clearly wins. In cold, wet, or windy weather, many fly species remain active while bees stay in their nests. At high altitudes and in arctic regions, flies dominate simply because bees cannot sustain populations. In enclosed growing environments like greenhouses and polytunnels, flies can be easier to manage and less prone to the stress behaviors that bees sometimes exhibit under confinement. And for crops with small, complex flowers like cacao, flies are not just better, they are the only option.
The broader lesson is that pollination systems are more diverse and more redundant than the popular narrative suggests. When one pollinator group declines, others can sometimes compensate, and flies are the largest pool of backup pollinators available. Recognizing myophily as a major ecological force, rather than a footnote to bee biology, changes how we think about managing crops, conserving wild plants, and designing landscapes that support the full community of animals that keep flowering ecosystems running.