UNITED STATES DEPARTMENT OF AGRICULTURE edeLollow 
WASHINGTON, D C. | 
PARASITISM OF THE MEDITERRANEAN FRUIT FLY 
IN HAWAII 1922-1924 
By H. F. Wrtarp, Senior Entomologist, in Charge of Hawaiian Inspections, 
Plant Quarantine ‘and Control Administration, and T. L. Bissmiu, Assistant 
Entomologist, Division of Deciduous Fruit Insects, Bureau of Entomology } 
CONTENTS 
Page Page 
Pteanugiont 6h: Set ee ee a Sec 1G GSOIMMAR Yrs seers es ea er Ee ey ee ee li 
RECOLGS Of intestalione. 422 ee ee Qo) ALLEL LUTE sCLbe Ces = 5 Seek Sak Nn) Midna See Rehan ane 12 
IPATASIDISMUTOCORGS 420 ek tsa) eed eee ods 4 
INTRODUCTION 
When the Mediterranean fruit fly (Ceratitis capitata Wiedemann) 
arrived in Hawaii, where it was discovered in 1910, it found itself in 
an almost ideal environment. Owing to a favorable climate, an 
abundance and variety of host fruits, and a lack of natural enemies it 
spread rapidly. The temperature range in littoral Hawaii is such 
that this fly can reproduce rapidly during the whole year. It has 
been shown by Back and Pemberton (3, p. 75)” that in the lower eleva- 
tions of the islands 16 generations may be produced annually. There 
have been recorded in Hawaii 73 different varieties of fruits and other 
plants in which the Mediterranean fruit fly may reproduce, and at 
all times during the year some of these varieties are in bearing and in 
the proper condition for infestation. The species of insect enemies in 
Hawai that attacked it when it arrived were so few and ineffective 
that they had very little influencein checkingits spread; consequently, 
within a short time after it was discovered there it had become 
established upon all the larger islands of the Hawaiian group. 
The use of introduced insect parasites has been found a more prom- 
ising control measure under the peculiar horticultural conditions of 
Hawaii (where the majority of host fruits are either inedible or not 
worth the cost of spraying) than are the artificial control methods of 
spraying and the destruction of infested fruits employed in commercial 
fruit-growing areas in certain other parts of the world. In 1913 and 
1914 the government of the Territory of Hawaii introduced and 
established four species of parasites which attack the larval stage of 
the fiy. Three of the species were braconids and one achalcid. Two 
braconids, Opius humilis Silvestri and Diachasma fullawayr Silvestri, 
and the chalcid Tetrastichus giffardianus Silvestri were imported from 
South Africa, and the braconid Diachasma tryoni Cameron was intro- 
1 At the time of the collecting of the information contained in this circular Mr. Willard was entomologist 
and Mr. Bissell was plant quarantine inspector, both in the Division of Tropical, Subtropical, and Orna- 
mental Plant Insects, Bureau of Entomology. 
2 Italic numbers in parentheses refer to Literature Cited, p. 12. 
90085—30 
CIRCULAR No. 109 MARCH, 1930 | ete 
