The tractor-trailer fell on its side about 6:10 p.m. on a curve on a ramp from Route 896 to Interstate 95, said state police spokesman Sgt. Paul Shavack.
The rig, traveling from Florida to Maine, carried 460 crated hives, or an estimated 16 million to 20 million honeybees.
The driver and two passengers were able to get out of the vehicle, but were stung 50 to 100 times each, troopers said. They also suffered minor injuries in the crash and were taken to Christiana Hospital.
Shavack said there were reports of passers-by being stung.
State police have had an official honeybee swarm removal plan for 14 years and this is the first time they used it, Shavack said.
Shavack says three on-call bee handlers were sent to the scene and they are working with firefighters to spray water on the insects, the crates and the truck.
"There's no rounding them up," Shavack said of the bees. "The water will disperse and calm the bee activity."
He said he hopes once the bee situation is mitigated, troopers will be able to right the truck, move it and reopen the ramp to traffic.