every 20 minutes around the year. Most of these were found in travelers’ 
baggage. 
Evidence that all-out public help is neededtotighten the barrier is the 
fact that serious agricultural pests occasionally slip in. 
During the 1950's, people in the United States made unwilling 
acquaintance with five plant pests of other countries, each capable of 
costly destruction. The best measures known have been applied to eradi- 
cate or control each of the five, but some are still serious problems. 
These new troublemakers are: 
The khapra beetle. From its home in India, this beetle, known as one 
of the worst pests of stored grain, is now roving the world. It was identi- 
fied in stored grain on our West Coast in 1953, and since then more than 
600 storage buildings in the West and Southwest have been found to be 
infested. Eradicating the khapra beetle by fumigating entire buildings 
has cost more than $5 million. 
The spotted alfalfa aphid. This forage pest appeared in the Southwest 
in 1954 and--being light enough to ride the wind--it spread into 30 States 
in three years. In 1956, the spotted alfalfa aphid cost forage growers $42 
million. 
Witchweed. This harmless-looking weed from Africa and Asia sends 
out roots from its seed underground to feed on the roots of corn and other 
grass-family crops. When the strange weed was found growing in our 
Southeast in 1956, scientists soon warned that it must be fought as a worse 
threat to corn crops than the European corn borer. 
The soybean cyst nematode. This tiny eel-like wormfrom Asia multi- 
plies enormously in the soil and attacks soybean roots. It appeared first 
in North Carolina in 1954, and five years later had been found on 700 farms 
in eight soybean-growing States. 
Hoja blanca (Spanish for white leaf), A virus spread by a plant hopper 
causes this serious disease of rice plants. Hoja blanca has been of con- 
cern to rice growers in widening areas of Latin America since it was first 
found in the Western Hemisphere in 1952. Since the fall of 1957, hoja 
blanca has been discovered in three of our Southern States. 
The exact way in which these new pests entered the United States is 
not known. 
HOW THE PROTECTIVE SYSTEM WORKS 
The Agricultural Research Service of the U.S. Department of Agri- 
culture is the Federal agency responsible for protecting the Nation from 
foreign agricultural pests. This regulatory work is assigned to two divi- 
sions of the Research Service: the Plant Quarantine Division and the 
Animal Inspection and Quarantine Division. 
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