Three potentially dangerous insects for the agricultural industry have been discovered in Nogales since August, according to federal authorities.
Two of the pests - the weevil and shield bugs - have never been found before in the United States.
"The ramifications of something like this coming into the U.S. and having it infest here in the U.S. are quite extensive," said Brian Levin, spokesman for Customs and Border Protection. "It has a huge economic impact on the country as a whole."
Agriculture specialists working at the Mariposa cargo facility on Aug. 11 first detected an adult weevil, commonly found in southern Mexico and northern Central America, among pineapples and Persian limes from Mexico.
On Sept. 6, specialists discovered an adult Hemipteran insect among imported tomatoes from Mexico.
Tomatoes are considered to be low risk for pests; however, insects similar to the one found typically damage crops by piercing plant tissues and feeding on the juices.
Also on Sept. 6, two adult shield bugs were detected in a corn shipment from Mexico. Shield bugs have piercing mouthparts used to suck sap from plants and sometimes eat other insects.
Some pests are very specific in what they eat, but Levin says the insects feed on a wide variety of agricultural products.
It was the first time the weevil and shield bugs have been intercepted at a U.S. port of entry and the first time a Hemipteran insect has been intercepted at a port of entry from Mexico, Levin said. It was also detected at a Miami port on Aug. 20.
"It actually is pretty common to see pests and intercept pests (in Arizona)," Levin said. In Arizona alone, more than 5,000 pests were intercepted during the 2009 fiscal year."
Greg Rosenthal, spokesman for the U.S. Department of Agriculture, said the fact that the pests are unknown in the United States but are known to be feeding on plants makes their detection significant.
"There's really just not much known about them and their potential," Rosenthal said. "That's why we want to keep them out."