Examples of seasonal restrictions are those applied under the quarantines on account of the Japanese beetle and Mexican fruit fly. Under the Japanese beetle quarantine, certification of fruits and vegetables is required only during the summer or the period of heavy flight of the beetles.

The Mexican fruit fly quarantine provides for waiving certification during periods when no hazard of spread of the insect exists.

Certificates or permits are often issued to permit movement on the basis of annual or more frequent inspections, which determine apparent freedom from infestation of establishments growing nursery stock or shipping other regulated articles, or upon adherence by such establishments to specified practices that prevent the materials they wish to ship from becoming infested.

When inspectors cannot determine pest freedom in any other way, they must actually inspect the materials offered for shipment. It is usually a laborious and costly procedure, and other methods for assuring freedom from pests are used whenever possible. An example is the use of DDT in the soil used for growing nursery stock and other plants. DDT, worked into the soil at the rate of 25 to 50 pounds per acre, eliminates hazard of spread of white-fringed beetles and Japanese beetles in shipments of plants grown therein. Large amounts of nursery stock grown under specified conditions as to soil treatment with DDT thus may be certified for movement from regulated areas without further treatment as long as the DDT in the soil remains effective in killing the insects.

Sometimes it is necessary to move regulated products that may be infested to points within or outside the regulated areas for processing or other handling that will free them from infestation. When that is necessary, the movement may be allowed under a limited permit, which accompanies the shipment and is receipted for by an inspector at the point of destination.

Materials so moved are handled under specified conditions in transit to prevent any loss of the load en route that might spread infestation. At the processing plant necessary precautions are taken to keep the materials apart from those that originated in non-regulated areas and to handle them under conditions of sanitation that will prevent escape of infestation or contamination of other materials. Examples of regulated materials so handled are peanuts, stumpwood, and cottonseed in the white-fringed beetle regulated area and cotton products in the pink bollworm regulated area.

WHEN QUARANTINES are promulgated, amended, or revised, common carriers that operate within the regulated areas and postmasters at towns within such areas are notified of the quarantine and supplemental regulations. Information concerning them is also given as wide circulation as possible within the areas through newspapers. Known or potential commercial shippers of regulated materials are interviewed by Federal inspectors who explain the regulations to them and outline the conditions under which they may move their products. Most shippers and transportation agents thus become aware of the regulations and are willing to cooperate in preventing spread of insects or other plant pests. Occasionally through laxity, forgetfulness, or misunderstanding, shipments of regulated materials, which have not been certified as free of infestation, are accepted for transportation to distant points. It is seldom necessary, however, to institute legal proceedings against shippers or transportation agencies except in cases of flagrant violation of the quarantines.

There are always some individuals within regulated areas who are unaware of the regulations and of the hazard involved in making shipments of potential pest-carrying materials to other parts of the country. To ascertain compliance with quarantine measures, the Department of Agriculture maintains a transit-inspection service; inspectors are stationed at strategic transportation centers to inspect shipments that pass through such centers in moving from regulated to non-regulated areas. State quarantine enforcement officers assist in the work by reporting violations of Federal domestic plant quarantines that they find during their inspections of shipments to determine compliance with State plant quarantine regulations or that have been sent to them by the Post Office Department for inspection under provisions of the Terminal Inspection Act of 1915, as amended.

We believe that the few million dollars spent annually to suppress or prevent the introduction or spread of additional destructive plant pests are insurance for the future protection of the country's food supply and natural resources.

Public awareness of the importance to general welfare of quarantines and coordinated control and suppression programs has increased immeasurably since the first plant quarantines were put into effect.

HERBERT J. CONKLE is a graduate of Ohio State University. In 193o he began work with the Plant Quarantine and Control Administration of the Department of Agriculture in connection with enforcement of the Mediterranean fruit fly quarantine and since that time has had wide experience in transit inspection and other plant quarantine activities. In 1951 he became a member of the Washington headquarters staff of the division of plant quarantines.

Draeculacephala minerva, a leafhopper.