13 



as they fully mature, and the latter soon after its formation, but mostly 

 after it has fully developed. 



This is a microscopical insect, and is not seen with the naked eye. If 

 a leaf or fruit be picked for examination, mites will seldom be found on 

 them, as all fly away instantly upon being disturbed. The glass must 

 be placed before the object in such a manner as not to disturb them while 

 engaged in feeding upon the leaf or fruit. 



NOTES UPON THE RED SCALE OF CALIFORNIA. 



There are two red scale insects in this State which confine their attacks 

 to citrus trees. Prior to 1880 Professor Comstock visited this State and 

 carried on a series of experiments upon the red scale in Los Angeles. 

 The scale upon which he conducted his experiments he identified as the 

 Aspidiotus aurantii of Maskell, and which is the same scale as that 

 found throughout the Santa Ana Valley. This scale was introduced 

 into Los Angeles County on some orange trees imported from Australia, 

 and which were planted at the old Kellar homestead, on Alameda Street. 

 It was introduced into the Santa Ana Valley on some orange trees also 

 imported from Australia, which were planted in the Huntington orchard 

 at Orange. From those trees this scale spread. In San Gabriel a scale 

 insect made its appearance on some trees that were also imported from 

 Australia and planted in the Rose orchard. At that time orange and 

 lemon trees were only imported from Australia. 



My attention was called to this latter scale after it began to make its 

 presence felt. Upon examination I concluded it was a different insect 

 from the Santa Ana Valley variety. In 1880 I communicated these 

 facts to Mr. Alexander Craw, of Los Angeles, a very careful entomologist, 

 who visited the orchard and fully agreed with me in my conclusions. 

 In 1881 the late Mr. Cooke, then Horticultural Officer, visited Los An- 

 geles, and I took him to San Gabriel, and after careful examination he 

 also pronounced it different from the Santa Ana Valley scale. 



It has been said that "there may be two forms of the same insect." 

 If this be true, why are their attacks on the tree so different? Mr. Klee, 

 in his report as Inspector of Fruit Pests (Biennial Reports State Board 

 of Horticulture, 1885-6 and 1887-8), mentions the fact that the two in- 

 sects are different, but described the one prevalent throughout the Santa 

 Ana Valley and Los Angeles City as an "Australian type," and the one 

 prevalent throughout the San Gabriel Valley as a " Japanese type." 

 The trees that arrive from Japan are generally infested by this latter 

 species, but previous to 1880 no orange trees were ever imported from 

 Japan. The trees upon which both of these scales came were imported 

 direct from Australia, and beyond this we know but little; but all indi- 

 cations point towards Australia as being the home of both these scales. 



In 1880 I had the management of a large orange grove in Orange, 

 where I carried on a series of experiments covering a period of three 

 years. In 1883 I moved to San Gabriel, where I carried on a series of 

 experiments covering a period of two years. I was thus able to notice 

 the difference between the two insects. 



