FRUIT-FLY PARASITISM IN HAWAII DURING 1916 



By C. E. Pemberton, Assistant Entomologist, and H. F. Willard, Fruit-Fly Qtiar- 

 antine Inspector, Mediterranean Fruit-Fly Investigations, Bureau of Entomology, 

 United States Department of Agriculture 



Since the introduction of parasites of the Mediterranean fruit fly 

 {Ceratitis capitata Wiedemann) into the Territory of Hawaii in 191 3, by 

 the Territorial Board of Agriculture and Forestry, more or less continuous 

 notes have been kept, from month to month, indicating the extent of 

 parasitism exerted upon the larvae of the fruit fly by these parasites and 

 by other species subsequently brought in. Papers presenting sum- 

 maries of these records, separately for the years 1914^ and 1915,' have 

 already been published. Opportunity for special investigations of fruit- 

 fly parasites in Hawaii in 191 6 has made possible the accumulation of 

 much careful data on fruit-fly parasitism during this year, of much the 

 same nature as that given in the publications just cited, and it is the pur- 

 pose of this paper to give, possibly more in detail, some results of the work 

 in 1916. 



It is felt that a separate record of the conditions of parasitism as existing 

 in Hawaii in 191 6, three years after the first and probably the most 

 important of these introductions, will be of no little vaTue and interest to 

 entomologists, by way of comparison with the parasitism in 1914 and 

 1 91 5, for interesting developments in connection with the question of 

 general parasite introductions and as a necessary contribution to the history 

 of fruit-fly parasitism in Hawaii. 



The tabulation during most of the year of the exact degree of infesta- 

 tion of large quantities of host fruits of the fruit fly, from many localities, 

 has been an important part of this work (Tables I-III). All fruits col- 

 lected for parasitism records on their contained maggots have been 

 accurately counted and placed in separate boxes over sand. The fruit 

 is then kept in the boxes until practically all the contained fruit-fly 

 larvae have developed, emerged, and entered the sand below for pupation. 

 A record of the total number of larvae thus developing and pupating is 

 secured. The larvae quickly pupate after leaving the fruit. The pupae 

 are placed in vials and later carefully counted in determining the degree 

 to which they have been parasitized. The filuig of exact data of this 

 nature from year to year is necessarily the most reliable and positive 

 method of ascertaining the actual degree to which the parasites now 



' Back. E. A., and Pemberton, C. E. parasitism among the larv.E of the mediterranean fruit 

 FLY (c. capitata) IN HAWAU IN 1914. In Bien. Rpt. Bd. Comrs. Agr. and Forestry Hawaii. 1913/14. P- 

 ISJ-161. 1915. 



S parasitism among the I^ARViB op the mediterranean fruit fly (c. capitata) in HAWAU 



IN 1915. /n Jour. Econ. Ent.. V. 9. no. 3, p. 306-311. 1916. 



Journal of Agricultural Research, Vol. XII, No. a 



Washington, D. C. J*°- ■■*. 1918 



Is Key No. K— 59 



(103) 



