72 



parasite has been introduced that would keep in perfect check widespread 

 pest and life destroyer of fruit and other trees, the black scale, Lecanium 

 (Saisettia) olece. It was about this time that JRhizobius ventralis and JR. 

 debilis, and E. toowoomlce or lopliantce were acquired. Those, with the aid 

 of Tomocera californica and Ghrysopa caltfbrnica, did some splendid work 

 along the coast. Indeed, they made such a good showing that orchardists in 

 the interior had great hopes that they would control the scale everywhere. 

 Hundreds of thousands of them were colonised in every section of the southern 

 orchards, but after repeated trials, and after waiting a number of years for 

 them to be acclimated to our drier and hotter interior climate, we were 

 forced to give them up, and again resort to fumigation and spraying to relieve 

 the orchards." 



Speaking further on of the olive scale parasite, Scutellista cyanea, intro- 

 duced from South Africa into California in 1901, he says : " They increased 

 so rapidly that it was commonly thought that, finally, we had the right enemy 

 for the black scale, and that the pest wtis doomed. In two years' time I saw 

 in our country orchards where at least 60 per cent, of the black scale was- 

 parasitized in the month of August, and 'I, with the rest, thought that our 

 troubles with the black scale were at an end. The following April I looked 

 for a colony, but could find not find one. The same results had to be recorded 

 for May. In June, I could find a very few, as also in July. In thejatter part 

 of August they were very numerous again ; but I looked further this time, and 

 I found that while in some instances 60 per cent, of the old scale was para- 

 sitised, still from 75 to 90 per cent, of the young scale had hatched out on 

 the leaves and limbs of the trees." 



Among the most praised ladybird beetles introduced from Australia, where 

 it is certainly one of our best mealy-bug destroyers, is Cryptolcemus mon- 

 trouzieri, which did good service in Honolulu ; yet, in the same report, Mr. 

 Pease says : " Mealy bugs (Pseudococcus cilri) bid fair to be a most serious 

 trouble. They have a number of enemies (Cryptcilo&mus montrouzieri), but 

 their control of the insect is only partial, and so' not satisfactory." 



Professor A. J. Cook, another Calif ornian authority on parasites, speaking 

 at the same fruit-growers' convention, says, after praising both good and 

 doubtful insects : " We must gas unless our friends are masters of the 

 situation. To wait for the Scutellista or golden chalcid until our groves are 

 ruined, or materially injured, by the black or yellow scale is the height of 

 folly. The wise course would seem to be to fight our pests by the best 

 method, unless our enemies are sufficient to keep them down ; and in case 

 we do not have efficient parasites or predaceous species, to hunt for them 

 with the keenest vision we can secure." 



