358 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



birds of different although usually related species and genera. Some 

 of these cases can be explained by a circumpolar range and hence 

 possible contact of the hosts, but in most this explanation is unavail- 

 able. Indeed in most of these cases the host individuals of the dis- 

 tinct American and European species are absolutely restricted to their 

 Old World and New World habitats and never by any chance come 

 into contact with each other. But there is no question of the identity 

 of Mallophagan species found on these hosts. The speaker's solution 

 for this problem is that the parasite species of the different but related 

 host species has persisted unchanged from the common ancestor of the 

 two or more host kinds. 



The speaker pointed out that these problems of distribution of the 

 ecto-parasites, which always have been of large biologic interest and 

 importance, are now assuming, in the light of the discovery of the 

 disease-disseminating possiljilities of the parasites, a new interest. 



THE INSECTICIDE INDUSTRIES IN CALIFORNIA 



By C. W. WOODWORTH 



California stands foremost among the states in the use of insecti- 

 cides. Our annual bill for these materials amounts to somewhere in 

 the neighborhood of a quarter of a million dollars. More than half 

 of this money is sent out of the state but we possess a large and growing 

 insecticide industry which is reaching out for other markets and it is 

 likely that in the near future California will be exporting more insecti- 

 cides than are being imported. Indeed, I confidently expect to see 

 California take a leading place in the manufacture of insecticides. 



In this paper I do not propose to discuss either the technical or the 

 commercial aspects of this industry, interesting as these phases of the 

 subject might be, but rather the relation this industry bears to economic 

 entomologists. I am not sure we all appreciate the tremendous in- 

 fluence the manufacturers and dealers of insecticides are exerting. 

 They are in touch with a hundred growers where an Experiment Sta- 

 tion Entomologist reaches one. They have the last word when they 

 furnish the goods just as they are about to be applied. Their advice 

 will go far to confirm or to counteract our recommendations. 



The quality and uniformity of the insecticides are factors of highest 

 import and they are dependent solely on the care and honesty of the 

 manufacturer or dealer. 



The appreciation of the need of close co-operation is responsible 

 for one of the distinctive features of this association. While the 



