At first glance, it looked like an ordinary bag of rice — but close inspection by U.S. Customs and Border Protection officers at Dulles turned up the larvae of one of the world’s most destructive beetles.

Khapra beetle larva was found inside a rice-filled burlap bag packed inside one of three suitcases brought to the U.S. via Saudi Arabia. A second larva was found on the outside of the burlap bag. The beetle larva was positively identified by a U.S. Department of Agriculture entomologist.

The USDA considers Khapra beetles one of the most invasive species worldwide, officials said. The beetle is considered a ‘dirty feeder’ because it damages more grain than it consumes and because it contaminates grain with its body parts and hair, CPB officials said. Consumption of infected grain can cause stomach irritation and is especially serious in infants.