4 Eighteenth Report State Entomologist ok Minnesota — 1920 



Altho several minor diseases and insects were found this year, 

 none were of sufficient importance to necessitate withholding a cer- 

 tificate. Several interesting problems in the control of insects and 

 diseases have appeared. It is hoped that some time can be spent next 

 year in trying to solve the most important of these. Our efforts last 

 season in trying to stamp out the white pine blister rust were evidently 

 successful, for altho more time was spent this year than ever before 

 in hunting the disease, it was not found in a single nursery. 



The inspection of foreign shipments has been somewhat modified, 

 owing to the strict provisions of the new federal quarantine No. 1>7 , 

 dealing with the entry of foreign-grown nursery stock. As there ap- 

 pears to be a lack of proper inspection by European inspectors, it is 

 imperative that the small amount of material coming into the country 

 must be inspected more carefully than usual at the destination. The 

 value of state quarantines was emphasized this year when it was 

 learned that nine shipments of stock from an area in New Jersey 

 infested with the Gipsy Moth had been sent into this state in 1917. 

 Fortunately no trace of this dangerous insect was found in checking 

 uj) these shipments. 



In 1919 in examining a shipment of about three thousand Nar- 

 cissus bulbs from Holland, twenty per cent were found infested with 

 the Narcissus fly, Merodon cqiicstris Fab. In several bulbs there were 

 found, along with the narcissus fly. larvae which proved to be those of 

 the Lvmate onion fly, Eitiiients striyafiis Fall. This is a bad pest in 

 ]uu-t)pe and as it is possible that we were not able to intercept all the 

 infested bulbs, some may have escaped to become a new pest of onions 

 in Minnesota. 



The Minnesota quarantine against currants and gooseberries from 

 certain states on accovmt of the white pine blister rust was amended 

 on January 5. 1920. to allow entry of all species except the cultivated 

 black currant. The finding of much blister rust in Minnesota made 

 continuance of this quarantine unnecessary. A (|uarantine on corn, 

 except shelled corn or shelled corn products, from Massachusetts, New 

 Hampshire, and New York was established March 5. 1920, on account 

 of the presence of the European Corn Borer in those states. 



White i)ine blister rust. — In view of the general distribution of 

 blister rust infection in east central Minnesota as found in 1919, the 

 possibility of its comj^lete or partial eradication from the state was defi- 

 nitely abandoned and a permanent policy of local control adopted. 

 The United States Department of Agriculture, cooperating with us 

 in blister rust control, has foimd that the removal of all currant and 



