Customs officials at Washington metropolitan region airports discovered the world's "most destructive pest," the Khapra beetle, in passenger luggage on two recent occasions, U.S. Customs and Border Protection announced Thursday.

The Department of Homeland Security's agriculture specialists at Baltimore Washington International Thurgood Marshall Airport found two live adult Khapra beetles, one dead immature larva, and several cast skins in two pounds of insect-infested cow peas during a standard inspection Feb. 23, which are prohibited from being brought into the country.

The passenger carrying the prohibited peas was a New York City resident who was traveling to BWI from Nigeria. An Agriculture Department's entomologist confirmed on March 6 that the suspected toxic beetles were, in fact, Trogoderma granarium.

On Jan. 24, agriculture specialists at Washington Dulles International Airport found four live Khapra beetle adults, 12 live larvae, and a few dead larvae and cast skins throughout a five-kilogram bag of prohibited basmati rice. The passenger was a Washington, D.C., resident who had attempted to bring the item from Saudi Arabia.

The rice was incinerated. The bugs tested positive by the entomologist for the poisonous pest at a later date.

The Khapra beetle is highly destructive when added to stored grains, cereals, and seeds. It's referred to by CBP as a "dirty feeder" because it ruins more grain than it eats. In addition, it contaminates grain simply by rubbing its hairs and body parts against it.

Consuming the bugs can cause gastrointestinal issues in adults and will make infants sick.

They cannot be killed with insecticides and fumigants and are the only insect that CBP will take regulatory action against, even in a dead state.

A potential outbreak would have "massive, long-term" negative effects on taxpayers, CBP warned. In 1953, a California outbreak forced officials to spend $11 million on clean-up efforts, which would be equivalent to $90 million if it happened today.