Having invaded New York City’s bedrooms, retail stores, movie theaters and offices, bedbugs are now showing up with growing frequency in another place: public schools.

There were 1,019 confirmed cases of bedbugs in the 2009-10 school year — an 88 percent increase from the previous school year, according to Education Department records.

So far this month, the city’s 311 help line has received 22 calls about bedbugs in schools, its records show. It is unclear whether additional cases were reported by other means.

School officials declined to provide the full number of confirmed cases since classes started on Sept. 8. But the Education Department spokeswoman, Marge Feinberg, said there had been no instances of city schools being closed because of bedbugs.