India, Feb. 19 -- The U.S. Customs and Border Protection has returned a shipment containing leaf lettuce from Mexico after detecting the presence of a rare pest in the cargo.

CBP said in a press release that its agriculture specialists at the Calexico cargo facility intercepted an unusual insect within the red and green lettuce leaves while inspecting a cargo shipment on January 8.

After a detailed examination at the Department of Agriculture's Animal and Plant Health Inspection Service, the pest was identified as Campiglossa peregrina, which is part of the fruit fly family.

As a precautionary measures, CBP officials returned the shipment and its driver back to Mexico.

CBP said that it was for the first time that this species has been r...