Hoverflies, Beetles and Moths: India's Overlooked Crop Pollinators

Walk through a mustard field in Rajasthan in February and the hum you hear is not all honeybee. Look closer at the yellow flowers and you will find hoverflies, small, striped, and easy to mistake for bees, moving between florets with a speed and persistence that rivals anything Apis cerana manages. India has roughly 450 described hoverfly species, and their contribution to crop pollination has been systematically undercounted because most pollinator research begins and ends with bees.

Hoverflies belong to the family Syrphidae. Their yellow-and-black banding is a defence, not an identity, they carry no sting and produce no honey, but predators leave them alone because the resemblance is convincing enough. What they do carry is pollen, caught on the fine hairs of their bodies as they feed on nectar and pollen directly.

In mustard, coriander, sunflower, and mango, hoverflies have been recorded as the dominant non-bee visitor in multiple Indian field studies. A 2018 study published in the Journal of Apicultural Research found that in some Himalayan apple orchards, hoverflies accounted for more flower visits than honeybees during peak bloom. Their larvae, depending on species, eat aphids, decaying organic matter, or algae in water, meaning adult hoverflies arrive in fields already abundant with the food sources that support their young. They are not managed, not purchased, and not given credit on the label, but they are there.

Beetles were pollinating flowering plants before bees existed. The fossil record places beetle-flower interactions at roughly 200 million years ago, deep in the Mesozoic. Bees, by contrast, appear in the fossil record around 100 million years ago. Beetles got there first, and in certain plant families, they never handed the job over.

In India, beetle pollination is most significant in crops and wild plants with large, bowl-shaped flowers that hold pollen in quantity: custard apple, known locally as sitaphal, is the clearest example. The flowers of Annona squamosa open and close in a sequence that makes them almost inaccessible to bees but well-suited to the small beetles of the family Nitidulidae, which crawl inside, feed, and carry pollen from flower to flower as they move. Farmers who grow sitaphal in Maharashtra and Andhra Pradesh have long practised hand-pollination as a supplement, but the beetles doing ambient pollination in unmanaged orchards are rarely acknowledged as the baseline that hand-pollination is correcting for when it fails.

Beetles are also messy pollinators. They eat petals, chew anthers, and defecate inside flowers. This is not incidental damage, some plants have evolved to tolerate and even depend on this rough handling, because the pollen transfer that happens during the beetle's feeding is sufficient. The relationship is older than tidiness.

Pollination does not stop at dusk. In India's cotton-growing regions of Gujarat, Telangana, and Maharashtra, flowers that open in the evening or at night depend almost entirely on moths. Cotton itself is largely self-pollinating, but the wild relatives of crop plants, the weeds and hedgerow species that form the genetic reservoir agriculture draws on for breeding, are often moth-pollinated.

Hawk moths, family Sphingidae, are the most effective moth pollinators. They hover in front of flowers the way hoverflies hover in front of aphid colonies, and they carry pollen on their bodies and on the long proboscis they extend into tubular flowers. In the Western Ghats, hawk moths are documented pollinators of several endemic plant species, including some in the genus Impatiens, which grow along the edges of coffee and cardamom plantations and contribute to the forest cover that regulates the microclimate those crops need.

Light pollution is the primary threat to moth pollination that receives the least attention in Indian agricultural policy. Artificial light at night disrupts moth navigation, reduces the time moths spend foraging, and changes which plants they visit. A field surrounded by the sodium-vapour lights of a new highway or a poultry shed runs a measurable risk of losing its moth-pollination service without any pesticide being applied.

India's National Bee Board and its pollinator research funding are structured almost entirely around managed honeybee colonies. This is rational, honeybees are the most reliable, scalable, and economically legible pollinator. But it creates a blind spot. When a crop's yield drops and the managed hives look healthy, the investigation rarely turns to hoverfly habitat loss, beetle population decline from systemic insecticides, or moth disruption from light pollution, because those populations were never being tracked.

Research from the Indian Council of Agricultural Research has begun to map non-bee pollinator diversity in specific crop systems, but the work is patchy and underfunded relative to its agricultural significance. Countries with more complete pollinator monitoring, the UK's Pollinator Monitoring Scheme, for instance, have found that hoverfly abundance declined by 30 percent between 1980 and 2013 in surveyed regions, a figure that prompted direct policy changes. India has no equivalent long-term dataset for hoverflies, beetles, or moths.

The three groups are not interchangeable with each other or with bees. Each serves a different set of plants, at different times of day, in different microhabitats. Losing one does not mean another fills the gap. The mustard field in February and the sitaphal orchard in June and the coffee plantation edge at midnight are three different ecological contracts, and each one has a specialist that bees did not negotiate.