40 



THIRTY-FOURTH FRUIT-GROWERS ' CONVENTION. 



another parasite, Novius koehelei, was liberated in the orchards and 

 proved a good second for the Vedalia. Since that time growers have 

 hoped that equally good parasites would be discovered and brought to 

 our State to combat all of our insect foes. These hopes have been 

 crowned with varying degrees of success and failure. 



Probably the San Jose scale {Aspidiotus pernisciosus) was next in 

 importance to the white scale, as its presence and injury was widespread 

 and fatal to the deciduous fruit industry in many localities. Great 

 expense was incurred in combating this scale with salt, lime and 

 sulphur, kerosene emulsion, and other remedies for a good many years. 

 Persistent efforts were made to find the natural enemy of the "^scale, 

 and the effort was finally crowned with success. The San Jose scale 

 is kept in a satisfactory state of subjection by parasites — the Apheliniis 

 fuscipennis, Rhizohius lopliantae, Chilocorus hivuhierus, and others. 



A perfect parasite in one locality is not necessarily a perfect parasite 

 for the same scale in another locality. As an illustration, note the 

 trouble they are having with the San Jose scale in the Eastern States, 

 notwithstanding the efforts that have been made to introduce the 

 parasites there. The climate or other conditions seem to prevent the 

 perfect work that prevails here. This fact should teach us not to be 

 too hasty in declaring that we have a parasite for other scale pests as 

 soon as a supposed new parasite has been introduced into our State. 

 Every new parasite, no matter what its record or reported record in 

 some other country has been, must necessarily be tried out here and 

 should be given its just due and no more. We have too often had our 

 hopes raised by premature reports of perfect parasites being introduced 

 that after trial proved of no avail. 



The apricot scale, Eulecanium armeniacum, has never to my knowl- 

 edge been known south of the Tehachapi, but north of that has been a 

 serious pest. It is, however, now controlled by its parasite, Comys 

 fusca, which, like the parasite of the San. Jose scale, lays its eggs 

 beneath the scale, these eggs hatching in the proper season into larvae 

 which eat out the scale inside of its shell or house, pupates there, and 

 later the perfect fly emerges through a hole which it makes in the outer 

 covering of the scale. 



The soft brown scale (Coccus hesperidum) is also kept in perfect 

 check by its natural enemies, ehalcid flies and others. 



Aspidiotus liederae, A. camelliae repax, which are common feeders 

 upon oleander, English ivy, umbrella, privet, pittosporum, and other 

 varieties of plants, and which are sometimes found on the orange and 

 lemon, and then called lemon peel scale, are quite well controlled by 

 ehalcid flies, Rhizohiids, and Cliilocorus hivuhierus. 



Since 1893 we have had periodical reports that a perfect parasite 

 had been introduced that would keep in perfect check widespread 

 pest and life destroyer of fruit and other trees — the black scale 

 {Saisettia oleae). It was about this time that Rhizohius ventralis and 

 R. dehilis and R. toowoomhae or lopliantae were acquired. Those, with 

 the aid of Tomocera calif ornica and Chrijsopa calif or nica, did some 

 splendid work along the coast. Indeed, they made such a good showing 

 that orchardists in the interior had great hopes that they \M)uld control 

 the scale everywhere. Hundreds of thousands of them were colonized 

 in every section of the southern orchards ; but after repeated trials 



