Around half of British ladybirds could be wiped out in the next 10 years by a bullying bug from other countries.
The Harlequin ladybird, originally from Asia, has already been spotted in small numbers and experts are worried more of them will be flying around this year.
The Harlequins are bigger and greedier than British ones and eat lots more of the bugs that ladybirds snack on.
And when they've run out of bugs they can turn to smaller British ladybirds, butterfly eggs and caterpillars.
Scientists want people to help them keep track of the Harlequins as they try and work out a way to stop them spreading.
What do Harlequins in Britain look like?
orange with between 15 and 20 spots
black with two orange or red spots
black with four orange or red spots
they all have a white plate with a big black M-shaped marking on it, just behind the head
They are worried that many of the 46 different ladybird species in the UK could be wiped out.
If you spot what looks like a Harlequin ladybird the scientists want you to let them know using a website, including where it was found, how many were there and a photo if possible.
Now that the weather is predicted to get better all types ladybirds are expected to start waking up and begin looking for mates.