30 



PACIFIC TREK AND V I N 



A Valuable Parasite 



By JOHN 



What, from preseiu appeaiances, 

 gives promise of being one of the 

 most valuable insect importations 

 ever made into this State, is that 

 made something over a year ago by 

 the State Board ot Horticulture 

 from South Africa— the Scutellista 

 cyanea. For many years the black 

 scale (Lecanium oleae), has been 

 one of the worst pests of onr olive, 

 lemon and orange orchards. Nor 

 did it confine its destructive work 

 to these orchards alone, but had a 

 very wide range of food plants, on 

 all of which it was terribly destruc- 

 tive. It was, however, especially 

 destructive to the olive, and we 

 have known large orchards which 

 after being nursed for years and 

 every known remedy used to get rid 

 of this scale, have been dug up and 

 burnt-d, as ii was impossible to get 

 any rt turns on account of the de- 

 structive work of the scale. Various 

 enemies of the pest have been intro- 

 duced and most have done good 

 work, but n')ne have proved capa- 

 ble of coping with it, and it has in- 

 creased and spread, to the disgust 

 and dam.ige of our fruit growers. 

 The new parasite, however, is un- 

 doubtedly doing the work, and the 

 formidable black scale is disappear- 

 ing before it. 



The Scutellista cyanea is a very 

 small black fly, so small that un- 

 less one's attention was called to it 

 it would pass unnoticed. It is ex- 

 ceedingly pctive, jumping like a 

 flea at the least disturbance, and is 

 therefore very difficult to find in 

 the orchard, and in fact can only be 

 readily detected in the grub state. 

 To find it, take a black scale off the 

 tree carefully, so as not to spill its 

 contents, and examine it with a 

 good lense. If the Scutellista is 

 established you will likely find 

 mixed up with the eggs a very 

 small white grub, which is the 

 larva of the .scutellista, or if the in- 

 ,sect is further advanced, a little 

 black pupa may roll out. In the 

 latter ca.se there will be "o eggs 



ISAAC 



left under the scale, for it will have 

 taken all of them to biing the para- 

 site to its perfect state. 



One great feature of this parasite 

 is its powers of reproduction. It 

 breeds continually, as long as there 

 is any food for it to live upon. With 

 the Comys fusca, thepara.site of the 

 brown apricot scale, we know of 

 but one brood a year. This comes 

 out all at once toward the end of 

 May or in June, according to the 

 condition of the weather, but the 

 scutelli-sta continues to breed the 

 year round, and passes through all 

 its stages from egg to mature insect 

 inside of two months, so there are 

 at least six broods a year. When 

 we consider that each female lays 

 between one and two hundred eggs 

 it will be seen that us powers of re- 

 production are encrmans, and that 

 it must very soon overtake its food 

 supply, which indeed, where it has 

 been established, it is rapidly do 

 ing. The writer recently had occa- 

 sion to examine some trees infested 

 with the black scale, on which this 

 parasite had been colonized, and 

 under every scale he found a little 

 wriggling maggot of the scutellista. 

 Mr. J. W. Jeffrey, one of the Hor- 

 ticultural Commissioners of Los 

 Angeles county, and who h is never 

 favored the parasite theory of light- 

 ing our insect enemies, writes of 

 this : "Mr. Strong visited an or- 

 chard in Pasadena, to which a col- 

 ony had been sent. He found at 

 least a dozen scutellista in the pupa 

 rium stage in a section of pepper 

 limb not two inches long. The 

 puparia have .since all become 

 tran-sformed into the liveliest flies I 

 ever saw. I am usually very con- 

 .servative, but I am inclined to 

 think confess to an iuclinalioii 

 verging to great exjieolancy. Never 

 was there a ciuestion of so much 

 importance to our citrus fruit 

 growers." 



In the short time we have had 

 this in.sect its work has been won 

 derful, and if it continues it will 



E 



prove as great a boon to our State 

 as was the introduction of the Ve- 

 dalia cardinalis to which we owe 

 the fact that California is an orange 

 shipping State today. No one can 

 place an estimate upon the value of 

 these beneficial insects. In the 

 case of the vedalia its value is the 

 value of our entire orange produc- 

 tion for all time, as we could not 

 grow oranges were it not for its 

 labors in keeping the cottony cush- 

 ion scale in check, and we believe 

 that in this new parasite we have 

 another beneficial insect that will 

 prove .second in value only to the 

 vedalia. One great advantage the 

 .scutellista enjoys is that, in the 

 most dangerous portion of its exis- 

 tence, it is protected by the shell of 

 its host , The egg is laid directly 

 under the scale and there it hatches 

 and remains until it has pas.sed 

 through all of its changes and has 

 acquired wings, when it emerges 

 able to fly from all danger and 

 ready to start a new generation. In 

 securing this parasite, the State 

 Board of Horticulture has done an- 

 other great work for our fruit 

 growers, and one which they will 

 appreciate. 



Fertilizer Depot has been opened 

 by N. Ohlandt & Co. of San Fran- 

 cisco in San Jose, where a large 

 stock of fertilizers is kept on hand 

 for immediate delivery. Mr. Fred 

 R. Cook has be in placed in charge 

 as agent, and the office is now busy 

 sending out the company's circulars 

 to the many residents of this valley. 

 This circular contains a very valu- 

 able "Spraying Calendar" that 

 should be in the hands of every 

 orchardist. Books 5.ent free on ap- 

 plication to Fred R. Cook, Agent, 

 2.^0 North First street, San Jose. 



The Ivlitor of the P.\CIFIC TrEE 

 AND ViNic wants to know how 

 many snb.scribers read tne adver- 

 tisements. If you will send your 

 name and address, mentioning the 

 ad on the la'-l cover of this number, 

 you will receive free, postpaid, a 

 beautiful souvenir. 



