PREVIOUS WORK WITH INSECT PARASITES. 35 



once introduced this same Cryptolsemus, which is an Australian 

 insect, with the result that the Pulvinaria was speedily reduced to a 

 condition of harmlessness. 



It may be incidentally stated that within the past year efforts have 

 been made by the Bureau of Entomology to send the Cryptolsemus to 

 Malaga, Spain, for the purpose of feeding upon a Pseudococcus. The 

 first attempt was unsuccessful, and the results of the last attempt 

 have not yet been learned. 



Another importation of Koebele's into Hawaii was the ladybird 

 Coccinella repanda Thunb. from Ceylon, Australia, and China, which 

 was successful in destroying plant lice upon sugar cane and other 

 crops. Writing in 1896, Mr. R. C. L. Perkins stated that Koebele 

 had already introduced eight other species which had become natu- 

 ralized and were reported as doing good work against certain scale 

 insects. Among other things he introduced Ohdlcis obscurata Walk, 

 from China and Japan, which multiplied enormously at the expense 

 of an injurious lepidopterous larva (Omiodes blaclcburni Butl.) which 

 had severely attacked banana and palm trees. 



Koebele's travels from 1894 to 1896 were through Australia, China, 

 Ceylon, and Japan. In 1899 he left for Australia and the Fiji Islands, 

 and sent many ladybirds and parasites to Hawaii, especially to attack 

 the scale Ceroplastes rubens Mask. The Hawaiian Sugar Planters' 

 Association, an organization which was responsible for Koebele's 

 appointment, subsequently employed Mr. R. C. L. Perkins, Mr. G. W. 

 Kirkaldy, Mr. F. W. Terry, Mr. O. H. Swezey, and Mr. F. Muir. By 

 the close of 1902 sugar planters were especially anxious concerning 

 the damage of an injurious leaf hopper on the sugar cane, Perkinsiella 

 saccharicida Kirk. This insect had been accidentally introduced 

 from Australia about 1897, had increased rapidly, and by 1902 had 

 become a serious pest. Koebele had made an effort to introduce 

 parasites of leafhoppers from the United States into Hawaii, with 

 unsatisfactory results, and consequently in the spring of 1904 Koe- 

 bele and Perkins visited Australia and collected all possible parasites 

 of different leafhoppers. Altogether they succeeded in rinding more 

 than 100 species. Of these the following hymenopterous parasites 

 are said to have become acclimated in Hawaii : Anagrus (two species), 

 Paranagrus optabilis Perk, and P. perforator Perk, and Ootetrastichus 

 beatus Perk. These species are all parasitic upon the eggs of the leaf- 

 hopper. By the end of 1906 observations upon a certain plantation 

 indicated the destruction of 86.3 per cent of the eggs by these para- 

 sites. In addition to these egg parasites certain proctotrypid 

 parasites of hatched leafhoppers have apparently become established, 

 namely, Haplogonatopus vitiensis Perk., Pseudogonatopus (two 

 species), and Ecthrodelphax faircMldii Perk. Three predatory 

 beetles, namely, Verania frenata Erichs., V. lineola Fab., and Calli- 

 neda testudinaria Muls., were also distributed in large numbers. 



