April, '14] COOLEY: TWO NEW PESTS 193 



TWO NEW INSECT PESTS OF CURRANTS AND GOOSE- 

 BERRIES 



By R. A, CooLEY, Agricultural College, Bozeman, Montana 



The Montana Experiment Station is giving some attention to the 

 hfe history and means of controlling the currant fruit fly (Epochra can- 

 adensis Loew), and in this connection has found a small curculio, 

 Pseudanthonomus validus Dietz, destroying the fruit of the currant in 

 a mamier very similar to that employed by the dipteron mentioned. 

 The U-shaped larva of this beetle, feeding in the seeds, causes the fruit 

 to turn prematurely red and drop to the ground. The injury occurs 

 somewhat earlier in the development of the fruit, than in the case of 

 E. canadensis. No injury is done to other parts of the plant so far as 

 we* have observed. 



This species has been under observations in the college currant patch, 

 of about an acre, for three seasons. In 1911 and 1912, the injury was 

 severe, but no accurate estimate was made; in 1913 careful countings 

 and estimates showed a destruction of fully 40 per cent of the fruit 

 that set. Compared with the currant fruit fly in 1913, detailed count- 

 ings of each kind of larvse in four lots each of fifty injured currants, 

 gathered from both the bushes and the ground, showed the weevil to 

 be more abundant by three to one. From our experience, it is clear 

 that while in some years the fruit fly is more abundant, in others this 

 weevil is more destructive, and the two together in average years 

 destroy much of the crop. 



The adults appear in the spring by the time the young currants are 

 setting. Numerous punctures are made with the long beak on different 

 parts of the fruit, particularly around the point where the stems are 

 ■attached, and in the pits by the stem the eggs are laid. The larvse 

 hatching from the eggs pass to the center of the fruit and begin feeding 

 on the small seeds. They reach full size by about the time the cur- 

 rants are full grown. The injuries caused by the beetles close around 

 the stems result in a drying and weakening of the tissues at this point 

 and the currants are easily broken off. It is probable that a consider- 

 able portion of the feeding is done after the currants drop and we have 

 found the large larvae and fresh pupse in the shells of the fruit on the 

 ground. The pupal stage is passed in the destroyed fruit. From 

 the pupse, the adults emerge, are found for a short time on the bushes 

 and then burrow into the ground for hibernation. 



The periods required for the development of the various stages have 

 not been determined, but the approximate seasonal history is clear 

 and may be summarized as follows: The adult beetles pass the winter 

 in hibernation appearing in the spring and laying eggs on the young 



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