PORT ALLEN, La. — A virus has killed millions of crickets raised to feed pet reptiles and those kept in zoos.

msn.com | The cricket paralysis virus has disrupted supplies to pet shops across North America as a handful of operators have seen millions of their insects killed.

Some operations have gone bankrupt and others have closed indefinitely until they can rid their facilities of the virus.

Cricket farms started in the 1940s as a source of fish bait, but the bulk of sales now are to pet supply companies, reptile owners and zoos, although people also eat some.

Most U.S. farms are in the South, but suppliers from Pennsylvania to California also raise crickets.

The virus had swept through European cricket farms in 2002. It was first noticed in 2009 in the U.S. and Canada.

The virus marks the latest in a recent series of mass animal deaths.

Blackbirds fell out of the sky on New Year's Eve in Arkansas. In the days that followed, 2 million fish died in the Chesapeake Bay, 150 tons of red tilapia in Vietnam, 40,000 crabs in Britain and other places across the world.

However, biologists say these mass die-offs happen all the time and usually are unrelated.

Federal records show they happen on average every other day somewhere in North America