88 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



fumigate a mill is in the spring* or summer, nevertheless in any 

 season there are bound to be some larvae or pupa? secreted around the 

 crevices of the windows or in other situations where the gas does not 

 affect them. 



Out of the 77 nurseries in this State we have inspected, according 

 to law, 45. As you will see by looking at the Minnesota law, inspec- 

 tion of all nurseries is not obligatory. We found the nurseries for 

 the most part in excellent condition. A weak point in our law, how- 

 ever, has been brought to our attention. One or more nurseries evi- 

 dently buy trees from the South, from a region affected by the San 

 Jose scale, and sell to Minnesota patrons. It does not follow, neces- 

 sarily, that their trees are infested with this dread scale, because 

 those districts are fairly well controlled by inspectors, but it is not, 

 as we know from experience, a difficult matter for an infested tree 

 to be overlooked. The present law gives the entomologist no option ; 

 a man may own only a single acre of ground, or none at all; he may 

 have only a thousand trees or less, on rented ground, his entire busi- 

 ness consisting of buying and selling, yet the entomologist's cer- 

 tificate goes upon all trees handled by his agents, no matter from what 

 part of the country the trees may come. This is probably a matter 

 which can not be remedied here, and at any rate it would be more 

 properly discussed in a meeting of horticultural inspectors, and not 

 before this association. 



Experiments against the leaf -hopper (Empoasca mali Le B.) in 

 large nurseries have been continued during the past season. We have 

 used kero-water — 1 part kerosene to 15 parts of water — with consid- 

 erable success. We find, however, that, although we killed the young 

 hoppers, and the old ones also when well treated, nevertheless the 

 trees are again infested from sources outside of the sprayed portion. 

 The work will be continued another season. This pest has not ap- 

 parently been as troublesome this year as in preceding years. 



Our chief experimental work during this summer has been against 

 the cabbage maggot (Pegomya brassier Bouche), and a report de- 

 voted to this pest will be made later. As far as we have gone with 

 the work, Ave feel that the maggot can be controlled by the use of the 

 well-known carbolic emulsion. Tarred paper disks are not practicable 

 in Minnesota for many reasons. In the first place, cabbages are 

 undoubtedly raised in much larger numbers here than where the tarred 

 paper has been found successful. Secondly, the nature of the ground 

 where cabbages are for the most part planted is such that the paper 

 can not be so applied as to prevent the fly from ovipositing beneath 

 it. Further, in cultivation the earth is thrown over the paper, and 

 the men can not or will not keep the surface of the paper free from 

 earth. Finally, cabbages are for the most part set so deep in Minne- 

 sota as to make it impossible to put the paper around the root and 



