m 



BUG VS. BUG. 



By JOHN ISAAC. 



A somewhat small and unpretentious exhibit was that made at the 

 St. Louis Exposition by the California State Commissioner of Horti- 

 culture, but it was one that attracted a great deal of attention, especially 

 among scientific men and the more intelligent class of orchardists and 

 farmers who visited that great exposition. This exhibit consisted of a 

 very complete and well-arranged collection of the various insect friends 

 to which California owes so much of her prosperity, and which are ever 

 and continuously working in our interest. Many of these insects are 

 exceedingly minute, so much so as to be practically out of the range of 

 the naked eye. To overcome this difficulty they were displayed behind 

 magnifying glasses of sufficient power to enable them to be seen, while 

 descriptions of them and the work they are doing for our State were 

 made in plain language. The result of this has been a great deal of 

 inquiry from Eastern sources as to our beneficial insects and our Cali- 

 fornia method of fighting bugs with bugs. To answer these inquiries, 

 as well as to give our own people a wider knowledge of what our insect 

 friends are doing for us, the following pages have been prepared. 



Below is a list of the different insects exhibited at the St. Louis 

 Exposition by this Commission : 



PREDACEOUS COCCINELLLDvE. 



Beneficial Insects. Host Insects. 



Vedalia cardinalis Cottony Cushion Scale (Icerya purchasi). 



Novius koebelei . ...Cottony Cushion Scale (Icerya purchasi). 



Novius bellus Cottony Cushion Scale (Icerya purchasi). 



Vedalia sp. (black). Cottony Cushion Scale (Icerya purchasi). 



Rhizobius ventralis Black Scale (Saisseta olere). 



Rhizobius ventralis, larvae. .Black Scale (Saisseta olese). 



Orcus australasia Black Scale (Saisseta olere). 



Orcus chalybeus Yellow Scale (Chrysomphalus [Aspidiotus] citrinus). 



Rhizobius toowoonibre. . .. San Jos£ Scale (Aspidiotus perniciosus). 



Scymnus vagans Red Spider (Tetranychus telarius). 



Rhizobius debilis ... Various scale insects. 



Cryptokemus montrouzieri ..Mealy Bugs (Pseudococcus [Dactylopius] sp.). 



Hyperaspis lateralis Cypress Mealy Bugs (Pseudococcus ryani). 



Exochomus pilatii Various scale insects. 



Chilocorus bivulnerus... San JosS Scale (Aspidiotus perniciosus), and others. 



Coccinella sanguinea Various scales and aphids. 



Coccinella californica Various aphids. 



Coccinella abdominalis. Various aphids. 



Coccinella oculata Various aphids. 



Hippodamia ambigua Various aphids. 



Hippodaniia convergens Various aphids. 



