The Raspberry Mite. (Phytoptua rubi.) 



(PLATE VI., Fig. 4.) 



A new pest has been discovered, which has already caused 

 much loss to growers of raspberries, and threatens to affect 

 their production most seriously. It will be reme'mbered that 

 in the last two seasons, and especially that of 1892, many 

 canes have died away. This was attributed in some cases to 

 frost and to the raspberry moth, Lampronia rubiella. But upon 

 careful examination of the canes in the spring, no traces of the 

 caterpillar of this moth could be found. In October last, while 

 examining some shoots of raspberry canes for Byturus pupae, 

 it was noticed that the buds in the axils of the falling leaves 

 were brown at their tips, and that the autumnal or sheathing 

 embryonic leaves, or scales, were brown. As seen with an 

 ordinary pocket magnifying glass, they appeared to be injured 

 by frost. Under the microscope, moving mites were seen in 

 these sheathing leaves or scales, and in the inner layers of 

 leaves ; they resembled the black currant mite, Phytoptus ribis, 

 but under a lens of high power they proved to be of a somewhat 

 pinkish colour, and differed in other respects, from that species. 



These mites, like the mites of the black currant, feed upon 

 the juices of the tender leaf- and blossom-buds of the raspberry 

 canes all the winter, and prevent them from putting forth 

 leaves and flowers. It appears that the lower buds are 

 attacked first, and the mites move on up the stems of the canes 

 from bud to bud. 



DESCRIPTION AND LIFE HISTORY. 



This mite is an undescribed, and, it is believed, a hitherto 

 undiscovered species of the Phytoptidse, or gall mites. It is 

 quite invisible to the naked eye, and seems only as a mere speck 

 of dust with a pocket magnifier.. It is of a light pink hue, with 

 four legs having six joints. (Fig. 4, Plate VI.) The end joint 

 terminates in a sort of claw, which is furnished with branching 

 arms looking like feathers. There are three long hairs on each 

 side of the body, and one pair of very long hairs at the extreme 

 end. There are bristles, also, at the tail-end of the body, 

 placed between the long hairs, which appear in some way to be 

 connected with the locomotion of the mite. In moving, its tail end 

 is bent round from side to side, apparently to help it along. 

 Specimens of the mite under observation traversed the field of 

 the microscope in less than one minute. 



Eggs were seen upon the scales and leaves of the buds, 

 glistening specks, more of a round than oval shape. Mites of 

 all stages of growth, as well as cast skins of mites, were also 

 noticed among the colonies between the scales and leaves. 



