GENERAL ACCUTXT OF WORK DONE IX AUSTRA- 

 LIA. I'lJ] AXD THE L'XrrED STATES. 



The material on wiiieli this I bulletin, entitled "Leaf-Hoppers 

 and Their Xatural Enemies,"' is based, has been derived from 

 various loealities and som-ces, which are herewith specified. 



(I). In u)03 Mr. Koebele made extensive observations on this 

 subject in Xorth .\merica, chiefly in the states of Ohio and 

 California, and sent a large amount of living material to the 

 Hawaiian Islands. 



(2). In 1904 Mr. Koebele accomi)anied by the writer visited 

 Australia and a still larger collection of leaf-hop])ers and their 

 enemies was made in that country. 



(3). Tn the early months of 1905, after f returned to these 

 islands, Mr. Koebele spent a short time in r*"iji. continuing Aus- 

 tralian studies. 



(4). For several years the sugar-cane and some other leaf- 

 ho])i)ers and their enemies have been under close observation in 

 the Haw^aiian Islands, and a collection of tliese has been made. 



I will now make some remarks on these various expeditions, 

 showing what was achieved in each case. 



KOEBEI.E'S MISSION TO THE UNITED STATES. 



Mr. Kocl)cle's researches in Ohio in 1903 were ])rimarily un- 

 dertaken on information kindlv given him bv Dr. L. O. How- 

 ard, of the Department of Agriculture. A short time previously 

 Mr. Otto H. Swezey had discovered that certain leaf-hoppers 

 in that State were attacked bv Hymenopterous parasites, and 

 Mr. Koebele was notified of this fact by the chief of the ento- 

 mological stafif at \\'ashington. ^Ir. Koebele's investigations 

 resulted in the discovery of many such parasites, belonging to 

 the family Dryinidae. The appearance of these parasites is well 

 exemplified by the 'T^airchild paras'ite" (EchtJirodcl/^ha.v fair- 

 cJiildii) of the cane leaf-hopi^er, now S(j familiar to most Ha- 

 waiian cane-planters. 



In addition to these Drvinidae. the little M\-mari(l egg-i)ara- 

 site of Liburnia (Aiiagnis coliiiiibi) was discovered, and also the 

 common presence of the minute Stylopids of the genus Elcnchus 



d others. Finally there was procured a single puparium of a 



an 



