8 Hewitt, On a neiv PJiyiopJiagoiis Mite. 



fig. B a and b. Michael is doubtful whether the number of 

 spines is constant and Canestrini makes the number 

 different ; I have examined a number of specimens and 

 find that they are fairly, though not absolutely, constant in 

 number and position. The claws are stout and strongly 

 curved. The genital opening is situated between the 

 bases of the posterior pair of legs and the anus is more 

 posterior on the ventral side. 



This species was found on tulips, together with L. 

 insignis var. dissitnilis. The hyacinth and tulip are the 

 chief food plants of this mite ; bulbs of liliaceous plants 

 appear to be chiefly attacked, and it is popularly known 

 as the "bulb mite." It is also called the '' EucJiaris mite," 

 on account of its apparent preference for the bulbs of 

 that plant, but it is no doubt more frequently found on 

 Encliaris bulbs, on account of their greater value, which 

 results in greater care and examination of the bulbs. 

 Claparede (i86S) found it in hyacinth bulbs, and also on 

 dahlia and potato tubers ; in the one case he named the 

 species R. dujai-dini, and in the other he gave it the name 

 R. robini, not recognising that the male was dimorphic 

 in the character of the third pair of legs, which in some 

 specimens are very stout ; he mistook the thick-legged 

 form of the male for the female. It has been recorded on 

 the roots of the vine. As it is responsible for considerable 

 damage to such plants as hyacinths, tulips, onions, etc., 

 this mite is of economic importance. It is supposed by 

 some authors to follow decay, but I have found it attack- 

 ing fresh bulbs, and Michael finds that it usually prefers 

 these. I have not only found it between the scales, but 

 also beneath the epidermis, where it was attacking the 

 softer tissues. Apart from the damage for which it is 

 directly responsible, it provides entrance for fungal and 

 bacterial organisms, which produce further decay. 



