62 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



city, is fairly common in sugar-cane fields. Additional material of 

 Rhizohius ventralis, too, seems to have been imported about this time. 

 This useful ladybird is still in evidence, especially during the winter 

 months of the year, upon trees infested with Pseudococcus nijxv Mask. 



Unfortunately, the entomological reports published by Mr. J. Mars- 

 den are of too vague a nature to give one an accurate idea of the 

 exact results of INIr. Koebele's importations. But in his roaming 

 style Mr. Koebele gives, in his report to the minister of the interior," 

 a mine of information on the injurious insects, native and introduced, 

 and their enemies found here. Over two years ( 1894-1 80G) seem to 

 have been consumed in that trip of exploration, the results of which 

 are no less a triumph than the original introduction of Vedalia car- 

 dinal In into California. 



The shade, citrus, and coffee trees cleaned of their worst scale 

 insects and plant lice, and the sugar-cane aphis materially checked 

 in its progress, the intrepid fighter and acute observer and collector 

 next turned his attention to Lantana and the hornfly {Ilannatobia 

 iserrata K.-D.), the two great impediments in the way of the cattle 

 ranchman. Mexico being the native home of the former, and the 

 latter being a common pest in the United States, Mr. Koebele turned 

 toward the American mainland in 1898. California, Arizona, 

 Mexico, and Peru were visited, and numerous insects shipped from 

 there, as related in the entomologist's report to the minister of the 

 interior for 1898, page 105. These comprised principally enemies of 

 cow-dung maggots and parasites of the cabbage butterfly {Pontia 

 rapoi Schrank). Some 20,000 specimens of Copidosoma truncatel- 

 lum Dalman were liberated with the hope that they would prey on 

 the larvge of the numerous lepidopterous enemies here. From Cali- 

 fornia a species of rock lizard {Gerrhonotus carinatus) was intro- 

 duced and liberated on Lihue plantation. 



In Morelos, Mexico, Lantana enemies were studied, but apparently 

 none were then introduced. The introduction of plant parasites is 

 always fraught with danger, and having been warned by authori- 

 ties against such an attempt, Mr. Koebele seems to have refrained 

 from the responsibility. 



It is interesting to note that in the report last referred to Mr. 

 Koebele devotes nearly two pages to remedial measures against the 

 hornfly {H. serrata). This brings us to an interesting point in the 

 activities of an economic entomologist in Hawaii. Granting that 

 most of our insect pests, consisting, as they do, of introduced species, 

 are most easily and as effectively kept in check by their natural 

 enemies, we must remember that these are not always to be had at the 

 entomologist's bidding. Repeated attempts to discover effective 



o Dec. 31, 1897, pp. 105-137. 



