YUBA CITY, Calif. (AP) — Authorities are investigating the theft of nearly 100 beehives from an orchard in northern California.

The beehives, which are used to pollinate almond orchards, were discovered missing on Friday, beekeeper Mike Potts said. He estimated that the theft of the 92 hives, about a third of his operation, would cost him about $44,000 in revenue.

“It’s hard enough keeping the bees alive without someone stealing them. It’s frustrating,” Potts told KCRA-TV.

Potts, who is based in Oregon, suspects that another beekeeper who lost bees could be responsible for the theft and may have stolen hives before. Given the weight of the hives in addition to the boxes that hold them, he thinks the thief may have used a flatbed truck to drive them away.