INSECTS ATTACKING THE PEAR, AND THEIR CONTROL 1037 



a combination of treatments 3 and 4, or 3 and 5 should be suffi- 

 cient. Sonic ^rowers have entirely controlled the psylla with 

 treatment 3 alone, to kill the hibernating flies. Where adjacent 

 orchards are neglected, however, it may be necessary to make appli- 

 cations during the summer so as to control invaders from such 

 unsprayed plantations. In this event frequent and thorough 

 spraying with nicotine solution and soap is advised. 



The Pear Slug 



The larvae of this species, Eri&cwmpoides limacina Retz., are 

 small, shiny, dark green or almost black, sluglike creatures that 

 feed 011 the upper surface of the 

 leaves, leaving the skeleton of veins 

 and the lower epidermis that turn 

 brown and wither. There are two 

 broods during the year. This in- 

 sect appears in destructive numbers 

 only in occasional years. 



Trc/ihnaif. Apply arsenate of 

 lead, two pounds to fifty gallons of 

 water, as soon as the pests are de- 

 tected. Dusting of foliage with 

 freshly slaked lime also affords 

 efficient protection from the insect.* 



FIG. 317. THE PEAR SLUG: 



LARVA AND WORK ON LEAF 



(After Webster). 



The Blister Mite 



The blister mite, Eriophyes pyri (Pgst.) Nal., is responsible 

 for dark brown or blackish patches, or blisters, of various sizes 



FIG. 318. THE BLISTER MITE: ADULT (enlarged) 



that may cover much of the leaf and sometimes cause it to rupture 

 in one or more parts, especially along the margins. The mites 

 burrow into the leaves from below, and the irritation they cause 



