Till. MONTH] V B1 I.LET1X. 



259 



The dark curranl fly 

 body is Mark, with four 



riff 



Km. 73. — Wins of the dark 

 fly, i RhagoU lis ribicola, 

 showing four crossbands. 

 Inal. i 



Description. 



is about half as large as the house fly. The 

 broad longitudinal white stripes on the thorax, 

 and a large yellow spot on the scutel- 

 hiin. The head is pale yellow, with 

 greenish eyes. A white stripe is pres- 

 ent on the second, third and fourth 

 abdominal segments. The legs are 

 pale yellow in color. The wings are 

 crossed with four brown bands, as 

 shown in the accompanying; figure. 



The following; notes on the life his- 

 tory, nature of injury and control are 

 taken from Piper and Doane's (3) 

 work on this pest in the state of 

 Washington. 



currant 

 Doane ) 



(Orig- 



Life History. 



These flies may be found around curranl and gooseberry bushes 

 from about June 15 to July 15. The female usually deposits a single 

 egg, sometimes two. beneath the peel of the berry. The egg- period was 

 qoI determined. As soon as the maggot hatches it cats its way toward 

 the center of the berry and feeds there, becoming full-grown in three 

 or four weeks. "When mature, the larva bores out of the fruit, enters 

 the soil a short distance, or conceals itself beneath leaves or rubbish, 

 and pupates. The rest of the summer and winter is passed in a brown 

 or black puparium. The fruit flies emerge during' the following spring. 



Nature of Injury. 



A word or two in regard to the nature and extent of injury may he 

 of interest. A (rw days after the egg is deposited a brown spot begins 

 to appear and increases in size until it is about the size of a pinhead. 

 The berry ripens prematurely. A large per cent of the infested berries 

 drop to the ground before the larva' are mature; some of the fruit. 

 however, remains on the bushes, the full-grown maggots make their 

 way through the peel ami drop to the ground. The amount of injury 

 varies from year to year, being much worse some seasons than others. 

 A few wormy berries in a crate, however, is enough to make the whole 

 lot unusable, for it is quite impracticable to separate the infested 

 berries from the sound ones. 



Distribution. 



Bhagoletis ribicola has been recorded from the state of Washington 



and northern Idaho. Aldrich I 1 I states that "it is a native species, as 

 1 collected an adult on a wild gooseberry at Pollock. Idaho, many miles 

 from a railroad; its original food was doubtless the wild species of 

 currant and gooseberry, so abundant in the Pacific Northwest." The 

 fact that our specimen was collected at an altitude of 7,500 feet indi- 

 cates that this pest lias not been introduced into California, but that 

 its Dative home also includes this state. 



