24 BULLETIN 134, U. S. DEPARTMENT OF AGRICULTURE. 



of little economic importance because of their natural enemies, or 

 for some other reason. But the lack of preventive measures in those 

 countries as compared with California and Florida is largely a ques- 

 tion of standards. 



The black scale is as serious a pest in Spain as it is in California. 

 A large share of the million dollars a year spent in California for the 

 control of citrus pests is counted against this insect. The black scale 

 is not, however, as serious a pest in Sicily as it is in California and 

 Spain. The purple scale injures trees and mars fruit in Spain and 

 Italy as it does in California and Florida. The long scale is more 

 injurious in Spain than it is in Florida, so far as the writer's observa- 

 tions have extended in Florida. This scale is not reported from 

 Italy. While it is recorded from one or two small sections in Cali- 

 fornia, it is of no consequence as a pest. Parlatoria zizyphus not 

 infrequently causes a heavy dropping of the leaves, and also attacks 

 the fruit both in Spain and Italy. It is not a general pest in the 

 groves of California or Florida. It is often taken, however, on lemons 

 in the markets of the eastern States, having been imported from 

 Italy. Aspidiotus liederae is a more serious pest on ripe lemons in Italy 

 than it is anywhere in the United States. The mealy bug, Pseudococcus 

 citri, ranks just as high, if not higher, as a pest in Spain and 

 Sicily than it does in California. The citrus white-fly, the most 

 serious of the Florida citrus pests, does not occur in the Mediter- 

 ranean region. 



Nothing in the way of artificial control is practiced against any 

 of the foregoing insects in any of the Mediterranean countries. One 

 or two cases were met with in Spain where the grower had tried 

 some patent concoctions on a few trees. Pruning, however, may come 

 in the category of control for insects in those countries more than it 

 does with us, as the following dialogue may illustrate : "What do you 

 do for the scales when they actually kill the twigs and branches as 

 seen on the trees before us V "We cut out the twigs and branches." 

 Cutting out dead twigs and branches is, of course, a part of the prun- 

 ing process, and not infrequently these dead parts are due to one of 

 the foregoing insects. If the fruit is infested with the sooty-mold 

 fungus, it is washed in sawdust, but the cause is not taken into con- 

 sideration. If scales are present on the fruit, such fruit is placed 

 in an inferior grade, or it is consigned to the by-product factory. 



In the case of ChrysompJialus dictyospermi, however, a start in 

 control work is really being made both in Spain and in Italy. This 

 is no doubt due to the fact that this scale causes more complete 

 injury to the trees — indeed, practically kills them. As before stated, 

 fumigation was seen practiced in Spain last year at Piaporto, Picafia, 

 and Piug in the Valencia section. Possibly it is practiced also in other 

 places, but evidence was not seen elsewhere at the time of the writer's 



