Some of the country's most widespread ladybird species have suffered significant declines in the past two decades, the first atlas of the well-loved bug has revealed.
The new publication maps all 47 different ladybirds in Britain and Ireland, and reveals that in the UK more than a fifth - 10 species - have been decreasing in the past 20 years, including the widespread 14-spot and 10-spot ladybirds, as well as rarer species such as the hieroglyphic ladybird.
And, since the arrival in the UK in 2004 of the invasive Asian harlequin ladybird which came from the continent where it was being used to control pests, the two-spot has also been in decline.
Harlequins compete for food and prey on the larvae of other, smaller species such as the two-spot and since its arrival, the species has racked up 25,676 records of its presence across the country. The figure puts it only second to the most commonly recorded species, the seven-spot ladybird, which has 27,000 records in Britain and Ireland in data stretching back over the last century.
Dr Helen Roy, from the Centre for Ecology and Hydrology (CEH) and one of the authors of the atlas, the result of a six-year research project, said: "What's quite striking is that in the same way as butterflies and moths have seen very common species going into decline, we're seeing the same happen with ladybirds."
But while butterflies feed on nectar from wildflowers, "ladybirds are predatory and carnivorous species" on the next level up the food chain, she said. "They are telling us there are changes going up through the food chain. Ladybirds can be used as indicators of wider changes in our environment."
Dr Roy said the atlas, which has information on the fortunes of all 47 species, shows five species were on the increase, with those such as the orange ladybird, which feeds on mildew, potentially benefiting from a warmer climate with hotter, wetter weather providing more of its food.
But she said it was not yet clear exactly what impact changes such as warming temperatures or the arrival of new species were having on the distribution of ladybirds, many of which favour urban areas.
The atlas is based on records originally gathered by experts but in the past few years receiving widespread contributions from the public through national surveys, with the enduring popularity of the beetle helping engage people in monitoring it.
The atlas author team also included Dr Peter Brown, from Anglia Ruskin University, Dr Remy Poland, from Clifton College, and ladybird recorder Robert Frost, and was supported by the Biological Records Centre.