2 i8 SCIENCE PROGRESS 



that these might be effectual in keeping it under control when 

 introduced into America. After much search and deliberation, 

 a species of ladybird indigenous to North-eastern China was 

 held to be best worth a trial for this purpose, and a number 

 were accordingly transported to the United States. In some 

 parts of the States the colonies of ladybirds thrived and did 

 vigorous execution on the scale-insects ; but parasites took 

 to preying upon them, while the use of washes as a means 

 of destroying the pest naturally led to partial or complete 

 starvation of the ladybirds. Attention has accordingly been 

 concentrated on obtaining the most effectual kind of wash, with 

 the result that a sheep-dip, into which lime and sulphur largely 

 enter, has been generally adopted. 



The use of this wash has brought the scale-insect to a great 

 extent under control ; and fears that fruit-growing would have 

 to be abandoned in many districts owing to its ravages may 

 be said to be practically at an end. Incidentally it has been 

 ascertained that the lime and sulphur wash has a most excellent 

 effect in destroying fungoid growths, so that its use is recom- 

 mended in the case of trees which show no signs of the scale. 

 Moreover, as in the above-mentioned instance of the cotton- 

 weevil, the presence of the pest has led to much greater care 

 on the part of growers in the matter of selecting, planting, 

 and tending fruit-trees, with the most satisfactory results as 

 regards the general condition of the orchards and the amount 

 of produce they yield. 



The third pest to which the Bureau has of late years directed 

 special attention is the gipsy-moth {Portketria dispar), also 

 an introduced species, whose native home is the European 

 continent. Unlike the cotton-weevil and the Chinese scale- 

 insect, the gipsy-moth has at present succeeded in invading 

 only a comparatively small tract of territory, being confined 

 to the eastern districts of Massachusetts, Rhode Island, southern 

 New Hampshire, and a few localities in Connecticut and Maine. 

 The invasion of this insect has raised the question whether 

 it is incumbent on States in which pests of this nature make their 

 appearance to bear all the cost of efforts made for their 

 extermination, or whether this should be shared by the supreme 

 Government at Washington. 



Although the gipsy-moth has an extensive range in the 

 Old World, inclusive of a large portion of Asia and North 



