THE NATURAL ENEMIES OF THE CITRUS MEALY BUG II 273 



numbers, however, that it will be but a few weeks until the whole orchard 

 will be clean. The upper orchard, where beetles were liberated at the end 

 of May last year, is practically free of scales, and from here the Rhizobius 

 have spread to the central orchard and can be found by hundreds upon every 

 tree. The beetles were seen in copulation everywhere, and on nearly every 

 branch the females were seen thrusting their eggs under the old scales. It 

 will be but a very short time until every tree is clean of scales, and no time 

 should be lost in collecting and distributing this valuable insect to all parts 

 of the State. . . . This beetle is one of the most common Coccinellids in 

 Australia, preying chiefly upon Briococcus, Rhhococcus, and various Lecaniini, 

 and upon these last it could always be found in New South Wales on my 

 last trip. On my first trip I forwarded this insect to Los Angeles from South 

 Australia and Victoria, where it was erroneously supposed to feed upon 

 Icerya. Within two years at the longest, I believe, that the various Lccanii 

 in California (and Florida) will have succumbed to the ferocity of this little 

 beetle."— Insect Life, Vol. VI., page 27, Nov., 1893. 



"The Pacific Rural Press of July 21, 1904, however, quotes a statement 

 made by ]\Ir. T. N. Snow in the Santa Barbara Press as to the progress 

 of this ladybird in the orchard of Mr. EUwood Cooper, at Ellwood, Cal. 

 According to this account a little more than two years ago 50 specimens of 

 Rhizobius ventralis were placed in this orchard, where they multiplied so 

 rapidly that in October, 1893, Quarantine Officer Alexander Craw was able 

 to secure there 500 colonies, numbering more than 10,000, for colonization 

 in various parts of the State. On June 27, 1894, Mr. Craw, it is reported, 

 again visited this orchard, and found not one black scale left of the army 

 which had been there, the Rhizobius having made a perfect clearance. Mr. 

 Craw is reported to have expressed to Mr. Snow his belief that by next 

 November there would not be a black scale remaining in Ellwood." — Insect 

 Life, Vol. VII, page 48, Sept., 1894. 



"Rhizobius ventralis (Black ladybird). This is also an Australian lady- 

 bird, introduced by the State Board of Horticulture through Mr. Koebele, 

 and is one of the natural enemies of the black scale (Saissetia [Lecanium] 

 oleac). This ladybird was introduced for black scale, and was generally dis- 

 tributed by the State Board of Horticulture wherever that pest was found. 

 It was one of the most promising of the many importations of beneficial in- 

 sects and took hold of its work with a vigor that gave promise of soon 

 extirpating one of the worst of the California scale insects. Wherever it 

 was introduced in the coast counties of the State, it increased with wonderful 

 rapidity and the scale as rapidly disappeared, and in those sections it still 

 continues to do good work, but eflforts to establish it in the interior counties 

 have not met with as good success, the heat probably being too intense for 

 the young larvae. This insect, however, is well established all over the State, 

 and in many sections is as abundant as any of our native species. Wherever 

 it is abundant, it is a chief factor in keeping in check the destructive black 

 scale." — John Isaac, in "Bug vs. Bug," page 10. Report of State Horticultural 

 Commission, 1906. 



