THE MONTHLY BULLETIN. 101 



met hods of control. AVorking upon the belief that the mealy bug was 

 attacking the roots of his orange trees, a grower in Ventura County 

 placed tanglefoot bands around the trees of an entire 100-acre block. 

 The orchard was closely watched for one and one half years by the 

 writer and nothing was observed that led to the belief that the mealy 

 bugs ever descended to or ascended from the roots. The roots of badly 

 infested trees were entirely exposed at various seasons, but without ever 

 finding the insects upon them. The tanglefoot did. however, catch 

 thousands of ladybird beetle larva? and adults, as well as other beneficial 

 insects, and were finallv removed because of this. These observations, 

 though they may hold true in only one locality for one and one half 

 years, do not necessarily prove such Avill be the case in other localities 

 or in the same locality for other years. 



ECONOMIC AND NON ECONOMIC SPECIES. 



The history of economic entomology shows that it is difficult for any 

 one to say whether an insect which is not an economic factor to-day 

 will not become so in the future, and while we may definitely state now 

 what species of meah' bugs are economic and what are not, it is not 

 our intention to predict that any of those listed as non-economic will 

 continue to remain so. In fact, in 1889, D. W. Cocj[uillett termed the 

 citrus species a "harmless mealy bug." The appearance of a native 

 species. Baker's mealy bug (Pseudococcns hakcri) in the citrus orchards 

 in a number of localities in southern California would indicate that 

 this native species might also in time become a pest of no little economic 

 importance. However, for the convenience of the growers, we desire 

 to list the species herein described as economic and non-economic. 

 Thase considered as non-economic have so far confined their attacks 

 only to native vegetation and have never proven a detriment to man- 

 kind. Those considered as economic may be considered under two 

 headings: those infesting only ornamental plants and those infesting 

 orchards and cultivated plants. 



Non-Economic : 



Pseudococcns aijrifolm Essig. 



Pseudococcus artemism Essig. 



Pseudococcns craivii (Coq.). 



Pseudococcns epliedrce (Coq.). 



Pseudococcus hymenoclece (Ckll.). 



Pseudococcns maritimus (Ehrh.). 



Pseudococcns qnercus (Ehrh.). 



Pseudococcus sali)ins (Ckll.). 



Pseudococcus seqnoke (Colm.). 



Pseudococcus yerha-santce E.ssig. 

 Of the foregoing Pseudococcus agnfolice, Pseudococcus quercus and 

 Pseudococcus scquoiee might be listed under those injuring ornamental 

 plants whenever the hosts are grown as such. 



