FELLESMERE, Fla. -

Charles Smith last saw his bees alive early last week.

When the Fellsmere beekeeper checked them Monday, his heart dropped as he saw the mounds of dead bees spilling out of all 400 of his hives off Babcock Street, about a half-mile south of Micco Road near the Indian River County line.

Another beekeeper about a mile south found a similar amount of his bees dead, around the same time, Smith said.

?This is a total wipeout,? Smith said as he opened the green wooden hives to show the destroyed honey. ?This is all no good. It?s been sprayed.?

He estimates he lost $150,000 in honey proceeds, the bees and their future generations.

The beekeepers aren?t accusing anyone, and Brevard County officials doubt recent mosquito control spraying in the area killed the bees.

But the die-off left behind the hallmarks of a pesticide kill, experts say, sparking a whodunit beehive mystery in South Brevard, Local 6 News partner Florida Today reported.

?Right now it?s too early to start pointing fingers at anybody,? said Bill Kern, an entomologist with the University of Florida?s Research and Education Center in Fort Lauderdale, who has been following the case. ?The fact that it was so widespread and so rapid, I think you can pretty much rule out disease. It happened essentially almost in one day. Usually diseases affect adults or the brood, you don?t have something that kills them both.?

State agriculture officials gathered dead and dying bees from both hives Thursday to test for pesticides. Results could take several weeks.

?Right now, we don?t know what pesticide, if any, was involved,? Kern said. ?If there?s a real high level, it?s going to be pretty obvious.?

Brevard County Mosquito Control sprayed the area ? just south of Deer Run subdivision ? by helicopter the night of Sept. 21, said Peter Taylor, an operations manger for the agency.

But that spraying of dibrom droplets wouldn?t have likely killed the bees, he said, because the pesticide only remains active about 30 minutes. They sprayed the area at about 9 p.m. that night, he estimates, when the bees would have been inside their hives.

?They?re still dying,? Taylor said Thursday, ?which indicates there is something that is more persistent than dibrom would be.?

Bees can carry granular pesticides back to hives, with deadly consequences, Kern said.

?There?s always the possibility that the bees could been in residential landscapes,? he said, ?that the bees could be picking up granular material, thinking it?s pollen and taking it back to the hive.?

Smith said no such granulars appear to be in any of the hives.

Bees also can transport pesticides from plants.

?That?s the biggest problem we have, is inappropriate application of an insecticide during a (plant) bloom,? Kern said.

Bees are crucial pollinators.

Farmers can raise avocado yields by 25 percent, for example, by using bees, according to the Florida Farm Bureau. They increase citrus yields, too, and squashes, melons, cucumbers. Cantaloupe can?t produce fruit without them.

Like canaries in a coal mine, bees also reflect the overall health of the environment. The nation has been undergoing a rapid loss of bees over the past few years that may signal a decline in the health of the planet, biologists say, and a symptom of a much larger environmental problem.

But experts say the recent South Brevard bee die-offs don?t fit the usual signs of so-called ?colony collapse disorder.? Usually, no dead bees are left behind in colony collapse.

Adult bees disappear from the hive, leaving behind the queen, boxes full of honey, pollen and a few other bees.

Scientists are studying multiple potential causes of colony collapse disorder, which some suspect may not even be a new phenomenon.

Inquiries have pointed to simple malnutrition, genetically modified crops, a mite that transmits viruses to bees, or some undiscovered pests or diseases.