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JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



coming established within the control official's territory, and of pre- 

 venting insects already established within his territory from assuming 

 the character of serious pests. 



Preventing Injurious Insects and Diseases from Becoming 



Established 



Control officials afe in substantial agreement that for preventing 

 undesirable insects from becoming estabUshed it is necessary to close 

 the channels through which they naturally enter. Differences of 

 opinion and practice obtain relative to the methods of closing these 

 channels. Some officials require merely that all nursery stock shall 

 come in under a regular certificate of inspection, totally ignoring the 

 fact that the certificate may mean much or little. Others require the 

 certificate and attempt also to determine to some extent the character 

 of the person or firm shipping goods into the protected territory. 

 Others require the certificate, inspect a certain percentage of the stock 

 and do or do not examine the standing of the shipper. Still others 

 examine all stock shipped in. 



Examination of the various insect control laws shows conclusively 

 that the practice of depending on the certificate is considered unsafe 

 by many of the control officials. Indeed, the various discussions of 

 the nursery certificate, which consume a part of the time of this asso- 

 ciation practically every year, serve to show that dependence upon the 

 certificate as a means of preventing injurious insects and diseases from 

 entering the control official's territory is dangerous. Many attempts 

 have been made to better the certificate by making it state more 

 specifically what it means. 



Doubt exists in the mind of the writer whether the attempt to make 

 the certificate more specific is really worth while in view of the fact 

 that such action is almost certain to increase the length of that already 

 in use or multiply the kinds used. Certificates are already as long as 

 will readily go on a shipping tag of convenient size, and any increase 

 in length is for that reason undesirable. The multiplication in type 

 means confusion to the agents of the common carrier and, to some 

 extent, both to consignor and consignee. A certificate properly dated 

 and signed is a certificate to the common carrier's agent and, speaking 

 generally, to the consignee. Further addition to the burdens of the 

 carrier's agents is likely to bring about disregard for the control offi- 

 cial's requirements. Furthermore, the consignee takes the certificate 

 to mean that the stock is not only free from the specified San Jose 

 scale and black-rot canker but from all seriously injurious insects and 

 plant diseases. The control official cannot escape responsibility for 

 the other parasites a given shipment may have by specifying the 



