New research is showing just how much plants and crops rely on a host of darkness-dwelling creepy crawlies.

Think pollination, and you will likely picture a butterfly or bee flitting between flowers. But while these are indeed important pollinators, both the natural world and our food supplies rely on a host of other creatures, some of them decidedly less appealing.

Most of the world's 350,000 species of flowering plants rely on animal pollinators for reproduction. Pollinators and their importance for ecosystems are increasingly in the spotlight in recent years due to the dramatic decline in their numbers. Birds, bats, bees, bumblebees and butterflies have all been affected, with some populations shrinking by 80% or more. The causes include habitat loss, pesticides and climate change.

And recent research has also shown that pollinator diversity is just as vital for ecosystems and cultivated plants as the sheer numbers of pollinators, and found that this diversity is on the decline for similar reasons.

Scientists estimate that 3-5% of fruit, vegetable and nut production is lost globally as a result of inadequate pollination, affecting the availability of healthy food and threatening human health.

From cockroaches and beetles to the tiny "bees of the seas", here are some of the most unexpected, and occasionally disconcerting, pollinators the world continues to rely on – even if we don't always see them.

Cockroaches are, in the words of one study, "among Earth's most despised creatures". But recent research suggests they play a beneficial and long overlooked role as plant pollinators – especially in the darker areas of forest often avoided by the world's more beloved bees and butterflies.

"Traditionally, pollination has been associated with bees, flies, moths and butterflies," says Kenji Suetsugu, a professor of biology at Kobe University in Japan. "However, emerging studies reveal that unexpected visitors such as cockroaches can play significant roles under certain conditions."

These "alternative pollinators", he adds, are often particularly important in environments where conventional pollinators are scarce, such as "in dense, shaded understories where light is limited and typical pollinators are infrequent".

In fact, a growing body of research suggests that cockroaches act as pollinators in a rich and varied range of ecosystems – a role that previously went mostly unnoticed by researchers, since the creatures are nocturnal and less obvious in their interactions with plants than bees. In recent years, cockroach pollination has been reported for plant species such as Clusia blattophila, which grows on rocky outcrops in French Guiana, and the rare and endangered Vincetoxicum hainanense in China, amongst others.

Suetsugu has studied the role of cockroaches in pollination in dense, evergreen forests on Yakushima Island, a lush, subtropical island off Japan. He was specifically interested in cockroach-assisted pollination of Balanophora tobiracola, a mushroom-shaped parasitic plant.

Since cockroaches are elusive and nocturnal, he used several tricks to better understand their interactions with this plant. For example, he set up a waterproof digital camera in front of one flowering plant which took photos of it in 50-second intervals from dusk till dawn for around three weeks. The resulting photographs – more than 34,000 shots – showed cockroaches visiting the flower at night. Suetsugu also captured cockroaches after they'd visited the plant to identify and count the pollen grains on their bodies.

To investigate how a single cockroach visit affected the plant's chance of setting fruit, he enclosed five of the plant's flowers with a fine mesh and opened it only for one visit by the Margattea satsumana cockroach (the most frequent cockroach visitor for this plant), then closed it again. He compared this with other treatments of the plant, such as covering the flowers with mesh for the entire flowering period, to exclude all pollinators.

The study, published in 2025, provides "the first direct evidence of effective cockroach pollination" in this type of plant, says Suetsugu. "In the case of a single visit [by a cockroach], nearly 40% of flowers developed pollen tubes, a strong indicator of successful pollination."

As soon as the first ever flowers unfurled from their buds in the early Cretaceous period, they were visited by pollinators. But those first soft landings on their petals weren't by bees or butterflies – instead, it's thought that the pioneers of pollination may have had six scuttling legs and tough, shiny shells. They were beetles.

Beetles remain important pollinators to this day, often visiting flowers with the most........

© BBC