142 PROTECTION OF PLANTS, 1916-17 



Family — Eriophyidae (Blister Mites) 



Pear-Leaf Blister-Mite. (Eriophyes pyri Pgst.) 



This mite is responsible for the reddish or yellowish blisters on the leaves 

 of pear and apple. These blisters turn brown later in the season, and badly 

 infested leaves drop. Nursery stock is often badly injured. 



The mites live in colonies beneath the epidermis, forming blister-like 

 galls. Within these galls the eggs are laid, hatched, and the young mites 

 grow to maturity. They then leave by a minute opening on the lower 

 surface and go to new leaves where new blisters are started. The winter 

 is passed as eggs beneath the bud scales. The adult mite is white, elongate, 

 four-legged, 1/ 125th inch long. 



Control. — Spray with lime sulphur wash before leaf buds open. 



Class Myriapoda 



Sub-Order — Diplopoda 



Millipedes 



Millipedes are often termed "thousand-legs," "galley -worms, "or "false 

 wireworms." They sometimes occur in rich garden soils containing much 

 refuse organic matter, and do considerable injury. They attack plants 

 grown from seed, and also gnaw holes in potatoes, strawberries and bulbs. 



The eggs are laid in holes in the soil in the spring, and it requires about 

 two years for the young forms to reach maturity. They are night-feeders. 

 The most common injurious forms belong to the Families Julidae and 

 Polydesmidae. Julus Canadensis is dark brown or black above with sides 

 spotted with yellow, and is from 1 to 2 inches long. Spiroholus is from 3 to 

 5 inches long. Polydesmus canadensis is a deep brown flattened form. 

 Julus virgatus injures lettuce and /. coeruleocinctus the fruit and roots of 

 strawberries. The young millipedes have only three pairs of legs. 



Control. — (1) Trap with slices of beet or potato; (2) Mix thoroughly 

 with the soil tobacco dust, gas lime (3 tons to acre in fall), or soot; (3) Give 

 the soil a thorough drenching with kerosene emulsion or two or three light 

 dressings of nitrate of soda (100 lbs. to acre). 



