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daceous or parasitic insect acquires a taste for it, or its natural enemy is 

 carried across the ocean. Scale insects adhere firmly to the trees and 

 plants on which they live, and consequently are easily transported alive 

 from one country to another, while the ladybirds, their worst enemies, 

 naturally drop from the trees when disturbed, and are left at home when 

 the trees containing the scale are shipped to another country. This 

 State has twice tried the experiment of sending an expert entomologist 

 to the home of the scale to find the predaceous insects that keep them in 

 check in their native country, and each time the experiment was "emi- 

 nently successful."' The experiment will always be successful if the 

 entomologist sent is competent, and the insects are properly cared for on 

 their arrival in this country. When we consider the ratio at which 

 scale bugs increase when unmolested by predaceous or parasitic insects, 

 we can readily see, if they were allowed to keep on increasing at this 

 ratio for twenty years, they would not have standing room on the face of 

 the earth; therefore, every scale bug must have a natural enemy which 

 keeps it in check. 



It should not require a great amount of effort on our part to convince 

 the next Legislature that the money expended in searching for preda- 

 ceous insects was the most profitable investment ever made by the 

 State, and to persuade it to continue this very profitable business. 

 In Professor Koebele's report he mentions several ladybirds which 

 would be worth thousands of dollars to the State if successfully intro- 

 duced. On page 16 he says: "A large number of predaceous insects were 

 found preying upon the red scale in Australia, and one of the Rhizobiids, 

 Rhizobiux satellus, was always present in extremely large numbers.' 7 

 On page 12 he says: u Rhizobius satellus are the most numerous insects 

 preying upon the red scale in Australia; " and on page 34 he tells about 

 three wild lemon trees that were so badly infested with red scale, that 

 any fruit grower in California would have given them up for lost, when 

 Rhizobius satellus stepped in and completely cleaned the trees in about 

 six weeks. What further evidence do we need to be convinced that this 

 is the ladybird that is destined to clean out the red scale in California? 



In Ventura County the black ladybird (Rhizobius ventralis) is increas- 

 ing rapidly on orange, lemon, olive, and apricot trees infested with black 

 scale, and we have already distributed quite a number of colonies of 

 home-grown beetles. We are confident that this ladybird will clean out 

 our Lecaniums as effectually as the Vedalia cleaned out the Icerya. 



In Los Angeles County a small black Scymnus (Scymnus nanus) has 

 been found feeding on red spider. Mr. Scott says it breeds rapidly and 

 has done good work during the past season in cleaning out this pest. 



The woolly aphis has done extensive injury to the apple trees in Ven- 

 tura County, infesting all kinds except those grafted on pear roots. 

 If we can keep the aphis out of the ground by grafting on resistant roots, 

 it will not be very difficult to keep the trees clean by Mr. Cooper's plan 

 of placing the eggs of our common ladybirds in the trees near the aphis. 



The pernicious scale still thrives with us, although we have the twice- 

 stabbed and brown-necked ladybirds to feed on it; but so far I have not 

 been able to find the internal parasite, Aphelinus fuscipennis, and this 

 probably accounts for the fact that the scale is harder to keep down here 

 than it is in Santa Clara County. 



This business of collecting and distributing ladybirds and parasites 

 to all parts of the State where they are needed is getting to be such a 



