PREVIOUS WORK WITH INSECT PARASITES. 

 Other Introductions by Koebele into California. 



31 



Mr. Koebele took a second trip to Australia, New Zealand, and the 

 Fiji Islands while still an agent of the Department of Agriculture, 

 but at the expense of the California State Board of Horticulture, and 

 in 1893 he resigned from the United States Department of Agriculture 

 and was employed by the State Board of Horticulture of California 

 for still another trip to Australia and other Pacific islands. He sent 

 home a large number of beneficial insects, nearly all of them, however, 

 coccinellids. Several of these species were established in California, 

 and are still living in different parts of the State. The overwhelming 

 success of the importation of Novius cardinalis 

 was not repeated, but one of the insects 

 brought over at that time, namely, the ladybird 

 beetle Rhizobius ventralis Er. (fig. 5), an enemy 

 of the so-called black scale (Saissetia olese Bern.), 

 was colonized in various parts of California, and 

 in districts where the climatic conditions proved 

 favorable its work was very satisfactory, nota- 

 bly in the olive plantations of Mr. Ellwood 

 Cooper, near Santa Barbara. Hundreds of 

 thousands of the beetles were distributed in 

 California and in some localities kept the black 

 scale in check. Away from the moist coast re- 

 gions, however, they proved to be less effective. 



International Work with Enemies of the Black 

 Scale . 



It will here be convenient to drop the chrono- 

 logical sequence with which the subject in hand 

 has been treated and to refer to the introduction 

 of a very successful parasite of the black scale, 

 whose work against this destructive enemy to 

 olive and citrus culture in California for a time 

 seemed second only to the success of the Novius 

 against the Icerya. In 1859 Motchulsky described, under the name 

 Scutellista cyanea (fig. 6), a very curious little hymenopterous parasite 

 reared by Nietner from the coffee scale in Ceylon. Subsequently 

 this parasite became accidentally introduced into Italy and was sent 

 to the senior author for identification by Dr. Antonio Berlese as a 

 parasite of the wax scale, Ceroplastes rusci L. As there are wax 

 scales (Ceroplastes jioridensis Comst. and C. cirripediformis Comst.) 

 which are more or less injurious in Florida and the Gulf States, an 

 attempt was made, with Berlese 's assistance, to introduce this para- 

 site at a convenient location at Baton Rouge, La., with the further 



Fig. 5. — Rhizobius ventralis, 

 an imported enemy of the 

 black scale: a, Adult lady- 

 bird; 6, larva. Much, en- 

 larged. (From Marlatt.) 



