157 



Division of Entomology 



ANNUAL REPORT. 



Honolulu, May 2, 1918. 

 Board of Commissoiners of Agriculture and Forestry, Honolulu. 



Gentlemen : — I submit herewith in accordance with the law a 

 brief report of the work of the Division of Entomology for the 

 annual period 1917-1918. 



No new work has been undertaken since the organization of 

 the Division at the beginning of the biennial fiscal period, July 

 1, 1917, owing to the uncertainties of travel caused by the Euro- 

 pean War. The beneficial insects previously introduced have 

 been propagated and distributed without interruption, although 

 there is abundant proof of their establishment. It is considered 

 that this practice is beneficial, since there is a tendency, in isolated 

 localities, without great quantity of variety of fruit, for the insects 

 to diminish greatly or to disappear from time to time in the ab- 

 sence of their hosts. This is especially true of those species with 

 weak flight, like Tetrastichus and Paranagrus. The latter does 

 not seem to be able to maintain itself, on the lowlands, in suffi- 

 ciently large numbers to be serviceable, and the practice with it 

 has always been to stock new fields of corn when the plants are 

 about a foot high, or to use a "catch crop" to multiply the 

 parasite. 



The distribution of the different parasites since January 1, 

 1918 (the date of the last report), has been as follows: 



TABULATION SHOWING THE LIBERATION OF BENEFICIAL INSECTS, 



1917. 



o 



Fruit-Fly Parasites* : 



TetrasticMis gifardianus 7,913 



Diacliasma fuUawayi . . . 675 



DiacJiasma tryoni 1,758 



Dirhinus giffardi 1,800 



Opius humilis 475 



Galesus sUvestri 455 



Total 13,076 3,220 245 160 97 16,798 



Horn-Fly Parasite f : 

 SpJangia cameroni 60 60 



* Liberated at: — Oahu: Honolulu, Mokuleia, Waiauae, Pauoa. Hawaii: 

 Kohala. Maui: Hana, Paia, Wailuku. Kauai : Liliue, Homestea^l. Laxai: 

 Keomuku. 



t Liberated at: — Oahu: Honolulu. 



