ACARINA OK MITES. 



117 



species in her Report for 1897 — ^ namely, Oribata lapidaria, 

 ■which has a similar life -history. These mites must not be 



Fio. 47. — Beetle Mite (OHbala orbieuMria). 



A, Adult ; B, immature form following the six-legged larval stage ; c, pseudo-stig- 

 matic organ ; Ai, ungues (claws) of adult ; Bi, ungues of B. 



confused with the mites that are parasitic upon beetles and the 

 BdellidcB or Snout Mites that we find on other insects. 



Family Phytoptidse or Gall Mites are minute mites which 

 live in the buds (Phyioptus ribis, avellanoB, and taxi) and in the 

 leaves of plants (P. pyri). The former produce large swollen 

 buds which never burst j the latter gall-like patches on the 

 leaves. Only two pairs of legs are noticeable in these minute 

 acari, but the two posterior pairs can possibly be identified as 

 four bristles. The skin of the Phytopti is always more or less 

 wrinkled, and may or may not be covered with a few scattered 

 hairs. These acari stop the growth of the plant by destroying 

 the buds, sometimes, as in the Currant Gall Mite (P. ribis), 

 quite killing the bush ; at others, as seen in the Yew Mite 

 (P. taxi), they produce stunted and deformed trees. 



The Currant Gall Mite is especially prevalent on the Black 

 Currant, where its presence may be detected in summer by the 

 large swollen green buds which do not generally burst into leaf 

 or blossom : in winter these large buds may still be seen, but 



