GOOSEBERRY AND IVY RED SPIDER. 33 



to me as present in great quantities near Cirencester, by Prof. Allen 

 Harker, of tlie Royal Agricultural College ; and, passing on to the 

 most northerly locality reported from, it was present to a very notice- 

 able amount up to the early days of June in the neighbourhood of 

 Perth. 



Not being sufficiently well acquainted with the Acarina to be able 

 to identify these Mites trustworthily myself, I applied for help in the 

 matter to the well-skilled determination of Mr. Albert Michael, F.L.S., 

 who kindly examined the specimens for me, and sent me, on the 11th 

 of May, the following reply:— "They belong to the genus Bryobia, and 

 are the Bnjohia prcetiosa of C. L. Koch, but I very much doubt this 

 species being different from the Bryobia speciosa of the same author ; 

 you might really call them by either name ; but this variety is Koch's 

 ' prcBtiosa.' The creature swarms in millions on Ivy in gardens at this 

 time of the year. I do not think that it usually does very much harm 

 to garden produce, as it prefers the Ivy, but sometimes it does a good 

 deal of damage. If there be Ivy in the garden it comes from, the 

 owner may probably get rid of the Mites at the expense of the Ivy ; if 

 he does not do this, the evil is likely to be recurring. You will find 

 that Andrew Murray and Koch class Bryobia among the Trombidiidae, 

 but this is an error; clearly its nearest ally is Tetranychns, the common 

 Eed Spider."— (A. D. M.)* 



At the heading of this paper a magnified figure is given of B. 

 prcEtiosa (taken from life last season), together with a copy of Koch's 

 outline figure of the B. speciosa. These give the general form, and 

 especially the great length of the front pair of legs, which is a charac- 

 teristic of the Bryobia (Koch). The size is difficult to state for general 

 purposes, but amongst the specimens I examined, the thirty-second of 

 an inch, that is, the quarter of the eighth of an inch, would give a fair 

 idea of the average length. With regard to colour, — amongst the first 

 specimens which were sent me on the 17th of March, from Great 

 Eversden, by Mr. Francis Nixon, the larger number were brickred of 

 various shades from bright to ordinary brick colour, and some much 

 deeper and duller in tint. These were in some instances moving about 



* In Murray's 'Aptera' a short description of the main characteristics of the 

 genus Bryobia will be found at i>. 117, followed by a figure of B. sjieciosa, after Koch, 

 in which one peculiarly distinguishing point of the margin of the abdomen being 

 set round with short papillse is indicated. In a paper on "The Clover Mite" 

 (another species of Bryobia, namely, B. pratensis), by Prof. C. V. Eiley and C. L. 

 Marriatt, given in No. 2 of Vol. iii. of 'Insect Life' (Washington), observations will 

 also be found regarding this belonging to the family of vegetable-feeding Mites, the 

 Tetranychidfe. These points are desirable to bear in mind now that they have been 

 clearly defined, to prevent the errors on the one hand of placing this little Mite in a 

 separate division from its nearest allies, and on the other of mistaking it for the 

 only too prevalent Ked Spider of the Hop and of other plants. — Ed. 



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