Protect caterpillars as UK’s moth population plummets, urge charities | Insects

As spring arrives and plants come to life, gardeners often fight a losing battle against caterpillars munching on their cabbages.

Traditionally, advice to gardeners regarding caterpillars has been about how to get rid of them and plug unsightly holes in plants. But the Royal Horticultural Society (RHS) and Wildlife Trusts are calling on Britons to take a relaxed attitude to the caterpillar carnage in order to support the moths many of them thrive on.

For particularly valuable plants, the RHS recommends a pesticide-free approach, including manual removal, physical barriers and pruning.

Moth populations are plummeting, charities have warned, and many of the UK’s 2,500 species are at risk, with their numbers having fallen by 33% since the 1960s. This is due to factors such as habitat loss, climate breakdown and pollution.

Helen Bostock, senior wildlife expert at the RHS, said: “Moths have long played second fiddle to butterflies in the garden, but understanding their value and needs, and those of their very hungry caterpillars, can support their recovery and help create a garden rich in biodiversity. »

They are not only important in their own right, but also provide an important food source for other imperiled garden wildlife, including birds, mammals and larger insects.

Some species of caterpillars roam the garden eating everything they see, while others are specialists. The RHS has encouraged gardeners to enjoy caterpillars in their garden. While some are large, green and easy to spot, others are camouflaged and look like twigs, bark or even bird droppings.

They transform into striking moths, including the pink and green elephant butterfly, the moon hornet butterfly disguised as a wasp and the contrasting red, cream and black Jersey tiger butterfly, which is becoming more common in the UK as the climate warms.

Caterpillars need a lot of energy to transform into a moth. The RHS has asked gardeners to “allow snacking on ornamental and vegetable crops”.

The charity also suggested planting native trees and shrubs favored by a wide range of caterpillars, including willow, honeysuckle, foxgloves, verbascum, comfrey, marjoram, bedstraw, sweet william, sweet rocket, tobacco plant, jasmine and campion.

Vicki Hird, insect expert at The Wildlife Trusts, said: “Moths have a stunning name and are beautiful in nature. The green, black and white day wonder appears to have been beautifully painted by an artist, and the white ermine appears to be causally draped in a black polka dot coat with a warm fur ruff.”

“It’s no wonder the French call moths “papillons de la nuit”. Even small brown butterflies can have wonderful, intricate markings. Making a simple butterfly trap is a wonderful way to appreciate these incredible creatures up close before releasing them into the wild.”

Caterpillar-friendly planting

• Digital: These pretty plants serve as food for many moths, including the small yellow underwings (Noctua arrives), moth (Phlogophora meticulosa) and the Hebrew character sebaceous (Xestia c-nigrum).

• Lady’s bedstraw: This native wildflower with foamy yellow flowers provides food for the hummingbird hawkmoth (Macroglossum stellatarum), the elephant butterfly (Deilephila elpenor) and the cleavers sphinx (Hyles Gallii).

• Mullein: These large, yellow, drought-resistant plants are favored by the brightly striped caterpillars of mullein (Cucullia verbasci).

• Mint: This provides food for the mint moth and the beautiful plume moth. It is also appreciated by bees.

• Hurdles: If you have space, a mixed native hedge planted with hawthorns (Crataegus monogyna), blackthorn (Prunus spinosa), hazel (Coryllus avellana) and rosehip (Canine Rosa) provides food for a multitude of caterpillars.