LOS ANGELES (CBS) — A wooden crate from Germany was seized by U.S. Customs and Border Protection agents because it was found to be infested with larva of the horntail wasp.

The crate was safeguarded and was sent back to be re-exported, authorities said.

“This interception is unique because CBP at LAX has only encountered this insect larva two other times, the last of which was over six years ago,” Todd Owen, LA director of field operations, said.

Horntail wasps are also referred to as wood wasps because the adult female lays her eggs inside of solid wood under the bark of dying, weakened or recently cut trees. The adult female drills holes with an organ that looks like a stinger, but doesn’t sting, and lays eggs into thick wood, which hatch into larvae in a couple of weeks.

Horntail larva resembles a milky white, legless caterpillar, according to the CBP.

The crates were found in an express air cargo facility at LAX and were labeled with compliant treatment marks.