April, '13] MORRILL: ENTOMOLOGICAL PIONEERING 191 



Valley, at elevation 1,100 to 1,300 feet the grape phylloxera is as yet 

 unknown. 



Among leaf hoppers the best known economic species are the sugar 

 beet leaf hopper {Eutettix tenella) occurring in the Salt River Valley 

 where it is apparently a native, and two grape leaf hoppers (Typhlocyha 

 comes), in the Gila Valley, and Dicraneura cockerelli in the Salt River 

 Valley. In view of the scarcity of representatives of the family Aley- 

 rodidse in arid regions, it is of interest to note that the larvae and pupae 

 of one apparently undescribed species of the genus Aleyrodes, fre- 

 quently nearly completely cover the under surfaces of the leaves of its 

 chief food plant, known as wild tobacco. 



The scale insects of Arizona are very interesting but can only be 

 touched upon in this paper. The San Jose scale was first recorded as 

 present in the Salt River Valley nearly twenty-five years ago. So far 

 as known this species is of no economic importance at present, since I 

 have never found it in orchards in the state, nor has a single in- 

 stance of injury by it been reported to my office. During the present 

 year it is planned to secure more definite information concerning the 

 status of this scale, and to determine if possible whether climatic con- 

 ditions or parasites are responsible for its apparent inability to main- 

 tain itself injuriously in the state. The soft brown scale {Lecanium 

 hesperidum) is notable in its occurrence in the Salt River Valley. Here 

 it seems dependent upon the oleander, a very common ornamental, 

 and rarely attacks the citrus, fig, china trees, pepper tree, rose or 

 other food plants except when such are located near to an infested 

 specimen of the preferred oleander. After the oleander is destroyed 

 the colony gradualh" weakens and disappears. On this food plant 

 the insect shows no preference for the shaded parts and in fact 

 the young appear to settle by choice upon the upper surfaces of 

 the leaves on the portions of the trees most exposed to the sun. In 

 Florida the soft scale thrives on young citrus trees to the full extent 

 permitted by its natural enemies, regardless of the existence of olean- 

 ders. During three years spent in Florida in white fly investigations 

 numerous instances of temporary injury to young citrus trees by the 

 soft scale were noted at Orlando and other points in that state, but 

 this insect was never so abundant upon oleanders as to attract my at- 

 tention. At my request, Mr. W. W. Yothers of the Bureau of Ento- 

 molog}^, stationed at Orlando, has recently made a special examination 

 of many oleanders in that city with the result that my impression con- 

 cerning this matter is verified. Prof. H. J. Quayle recently writes 

 that in California he has never observed any preference of the soft 

 brown scale for the oleander over other food plants. The California 

 red scale (Chrysomphalus aurantii) was discovered for the first time in 



