THE SUGAR-CANE LEAFHOPPER. 29 
More recently the species of beneficial insects which were already 
present in the islands when the leafhopper was introduced and 
which have sought the leafhopper in the cane fields have been reported 
upon in detail by the entomologists of the Hawaiian Sugar Planters’ 
Experiment Station.? 
SpEcIAL INTRODUCTIONS. 
In 1903 Mr. Albert Koebele, after consulting with Dr. L. O. How- 
ard, undertook extensive observations on the American parasites of 
leafhoppers. In Ohio Mr. Koebele had the assistance of Mr. Otto 
H. Swezey. A large quantity of living material was collected both 
in Ohio and in California and shipped to Doctor Perkins at Honolulu. 
-The American material consisted in the main of insects belonging 
to the hymenopterous family Dryinide. The Hawaiian parasite 
Ecthrodelphax fairchildu Perkins is also a member of this family 
and, at the time of Mr. Koebele’s American introductions, was 
being reared and distributed over the islands by Doctor Perkins. 
These introductions are discussed by Doctor Perkins in Part I of 
Bulletin 1, Division of Entomology, Hawaiian Sugar Planters’ 
Experiment Station, 1905.° 
Mr. Koebele also collected during his American investigations 
representatives of the order Strepsiptera (Stylopids) and a single 
species of an egg-parasite, Anagrus columbi Perk., belonging to the 
family Mymaride. ¢ 
In the spring of 1904 Messrs. Koebele and Perkins sailed for 
Australia to continue the search for parasites of the leafhopper. 
They reached Sydney in May and because of the cold weather which 
prevailed they proceeded to Brisbane. The results of the work in 
Australia are thus summarized by Doctor Perkins:4 
Early in June we arrived at Brisbane, and on the first cane that we saw, a few plants 
in the public gardens, we at once observed the presence of the cane leaf-hopper. A 
@ Leafhoppers and their natural enemies. <(Hawaiian Sugar Planters’ Exp. Sta., 
Div. Ent., Bul. 1. 
Perkins, R. C. L.—Part I, pp. 1-60, May, 1905. (£cthrodelphax fairchildit.) 
Perkins, R. C. L.—Part IV, pp. 113-157, pls. 5-7, September, 1905. (Pipunculide.) 
Terry, F. W.—Part V, pp. 159-181, pls. 8-10, November, 1905. (Forficulide, 
Syrphidz and Hemerobiide.) 
Swezey, O. H.—Part VII, pp. 207-238, pls. 14-16, December, 1905. (Orthoptera, 
Coleoptera, and Hemiptera.) 
6 Perkins, R. C. L.—Leafhoppers and their natural enemies. <Hawaiian Sugar 
Planters’ Exp. Sta., Div. Ent., Bul. 1, Part I, pp. 1-60, May, 1905. (Dryinide.) 
¢ PerKins, R. C. L.—Leathoppers and their natural enemies. <(Hawaiian Sugar 
Planters’ Exp. Sta., Div. Ent., Bul. 1, Pt. III, pp. 86-111, pls. 1-4, August, 1905. 
(Stylopide.) 
Perkins, R. C. L.—Leafhoppers and their natural enemies. <Hawaiian Sugar 
Planters’ Exp. Sta., Div. Ent., Bul. 1, Pt. VI, p. 198, November, 1905. (Anagrus 
columbi.) 
@ Perkins, R.C. L.—Leafhoppers and their natural enemies. < Hawaiian Sugar 
Planters’ Exp. Sta., Div. Ent., Bul. 1, introduction, pp. m1, 1v, May, 1906. 
