80 PROCEEDINGS OF NINETEENTH FRUIT GROWERS' CONVENTION. 



It is safe to say that many of the beetles were liberated in groves that 

 had not enough scale for them to live on, and consequently they had to 

 leave or starve. 



Last spring the weather was unusually damp and foggy with us, and 

 the conditions exceptionally favorable for all kinds of insects in our 

 orange groves. The kinds most numerous of all were the aphides, which 

 literally swarmed in millions, daubing the trees with their excretions, 

 furnishing a congenial soil for the spores of fungi, and gathering dust 

 from every passing wind. As a result of the accumulation of this filth, 

 and that of the black scale, many of the oranges had to be washed to 

 render them marketable. In due time the native ladybirds, and other 

 enemies of the aphides came and destroyed them, and we don't expect 

 another such visitation until we have a recurrence of like conditions. 



The presence of so much smut on the fruit was generally ascribed by 

 our growers to a phenomenal increase in the black scale, and many of 

 them took steps to secure large colonies of the Rhizobii for their groves. 

 Others applied to our city trustees to repeat the operations of last year, 

 and through both these means about 100,000 of the beetles were received 

 and colonized during the months of May, June, July, and August of 

 this year. These were placed in the groves by myself, and I was careful 

 to put them where they would find plenty of black scale to eat, and also 

 to put them in quite large colonies. Now in regard to the work which 

 these insects have done, I can state that some of the orchards which 

 were among the first to become badly infested in this valley, have been 

 completely cleaned, as a result of these and other predaceous insects. 



In this connection I will say there were nine or ten different species 

 of ladybirds, including Rhizobius and Scymnus, among the beetles we 

 got from Santa Barbara and Ventura Counties, and besides these the 

 " twice-stabbed" and " eyed" ladybirds have multiplied immensely in 

 our groves within the past year. In fact, we find very few trees with 

 any quantity of black scale, without rinding the mature beetles or 

 larvae and pupa cases of these ladybirds present too. 



I have found the mature beetles of the Rhizobius ventralis, "twice- 

 stabbed" and "eyed" ladybirds by the hundreds on some of our trees, 

 and with these were a good many " ashy-gray" and Rhizobius debelis, 

 and other species. On several occasions I have seen the trunks and 

 larger branches of both orange and olive trees literally covered with 

 these insects. It was very hot weather, and on some days the Rhizobius 

 ventralis came down and crawled into the ground, and I found them 

 under clods and in the soft dirt by the hundreds. This was about 

 September 25th last. Among others who were with me and saw the 

 same sight were Mr. Allum, of the "Riverside Press"; Messrs. Kingman 

 •and Bordweil, City Trustees, and Mr. L. C. Waite, a prominent orange- 

 grower. In view of the foregoing, it would be but natural to think the 

 people of Riverside would unanimously rely upon the beetles to destroy 

 their black scale; but not so. The question I am oftenest asked is: 

 Will the bugs eat up the black scale in my orchard so I won't have to 

 wash oranges next spring? I cannot give assurance that they .will, for 

 my experience has been that a year must elapse after colonizing with 

 Rhizobius before results can be seen, and when I tell them so, they 

 usually decide to have their trees sprayed. 



Our people have such a mortal hatred of scaly trees and smutty fruit, 

 that very few of them are willing to allow their trees to become sufti- 



