DEPARTMENT REPORTS. 129 



The climatic condidous seemed unusually favorable for the develop- 

 ment of the applc-ti'ce aphis and woolly apliis, but by ])ci'sistent sjjray- 

 inj;' with tobacco decoclioiis they were ]»r('ventcd from causing any 

 serious harm. The addition of one cake of hard soap, or a pint of whale- 

 oil soap to 50 gallons increased the efficiency of the spray. 



In most of the nurseries crown-gall was less troublesome than in 

 other years. Although it is not possible to make a very careful in- 

 spection before the trees are dug, all nurserymen are instructed to 

 destroy trees infested with this disease and to avoid using the same 

 land for growing two consecutive crops of trees of the same general 

 nature. 



FORKIGN NURSERY STOCK. 



In October, 1912, the U. S. Plant Quarantine act w^ent into effect and 

 in accordance with its terms importers of nursery stock are required 

 to take out a permit and duplicate notices of the arrival must be sent 

 to the Federal Horticultural Board and to the inspector of Nurseries 

 of the state to which the stock is consigned. Most of the stock brought 

 into Michigan is from France, Belgium and Holland. In the fall it 

 consists largely of azaleas and other shrubs for greenhouse forcing. 

 Later on, the bulk of the shipments are made up of apple, pear, plum 

 and cherrj' seedlings to be used as stocks hj nurserymen. Many thou- 

 sand maple and other shade trees, ev^ergTeeus and shrubs of small sizes 

 for growing in the nurseries are also imported. As spring comes on the 

 importations include hardy rhododendrons and box and bay trees for 

 porch decoration. 



The object of the U. S. Plant Quarantine law is to prevent the intro- 

 duction of dangerous insects and diseases, and an embargo has been 

 placed upon certain species of trees, etc., as for instance, the five- 

 needle pines, which are likely to be infected with the "white-pine rust," 

 but for the most part nursery stock is admitted provided it is accom- 

 ])anied by a certificate of inspection. Even then, however, the danger 

 from the introduction of certain insects is so great that the stock from 

 Western Europe is re-insj)ccted after it arrives in this country'. 



The gypsy moth and brown-tail moth are especially feared. In former 

 years, before the passage of the U. S. Plant Quarantine law, as many as 

 lO.OOO larvae of the brown-tail moth, contained in twenty-five nests, 

 were found upon the trees in a single box of nursery stock consigned 

 to a Michigan point. So far as is known neither of these insects has 

 been able to secure a foothold in Michigan, but eternal vigilance will 

 be needed to keep them out. For a number of years they have caused 

 immense losses in Eastern New England, where §1,000,000 annually is 

 spent in fighting them. A quarantine exists against that section to the 

 extent that all shipments of nursery stock have to pass a special in- 

 spection for the presence of these insects. 



During the fall, winter and spring montlis, the brown-tail moth is 

 in the form of small larvae, perhaps one-eighth of an inch long, which 

 are enclosed in silken nests attached to the branches. These closely 

 resemble the cocoons of some of the larger moths. 



At this same period the gypsy moth is in the egg stage. These will 

 be found in flattened patches an inch or a little more in diameter, upon 

 the stems and larger branches. The eggs resemble small pearls and 

 17 



