134 ACARINA OK MITES. 



mites. The adult has tridaotyle (aI) claws ; the larva and 

 nymph unidactyle claws (fii). The larva, like most mites, is at 

 first six-legged, but assumes four pairs before the sexual adult 

 stage. Miss Ormerod mentions another very abundant species 

 in her Eeport for 1897 — namely, Oribata lapidaria, which has 

 a similar life-history. These mites must not be confused with 

 the mites that are parasitic upon beetles and the Bdellidw or 

 Snout Mites that we find on other insects. 



Family Eriophyidse ^ or Gall Mites are minute mites which 

 live in the buds {Eriopliyes rihis, avellance, and taxi) and in the 

 leaves of plants {E. pyri). The former produce large swollen 

 buds which never produce fruit ; the latter gall-like patches 

 on the leaves. Only two pairs of legs are noticeable in these 

 minute acari, but the two posterior pairs may possibly be 

 represented by four bristles. The skin of the Eriophyidae is 

 always more or less wrinkled or striated, and may or may not 

 have a few scattered hairs. These acari stop the growth of the 

 plant by destroying the buds, sometimes, as in the Currant Gall 

 Mite [E. ribis), eventually killing the bush ; at others, as seen 

 in the Yew Mite {E. taxi), they produce stunted and deformed 

 trees. 



The Currant Gall Mite {E. rihis) (Hg. 60) is especially preva- 

 lent on the Black Currant, where its presence may be detected 

 in spring by the large swollen green buds which do not generally 

 burst into leaf or blossom : in winter these large buds may still 

 be seen, and many are brown in colour and dead. On examin- 

 ing the live buds in the winter we find all the acari safely 

 housed : here they live and breed. In the spring and summer 

 they come out and move over the bushes, taking up their 

 position in new buds, which they speedily deform. The ova 

 are laid in the buds, and soon hatch into mites very similar to 

 the adults. In form the Currant Gall JMite is elongated and 

 dirty-white in colour. This serious pest, which has spread at a 

 tremendous rate over Britain, has now appreciably been checked. 



' Formerly called Phytuptida', 



