GARDEN PESTS IN NEW ZEALAND 



presence are to be found in stunted growth and yellowing leaves, failure 

 of flower development, reddish spots on bulb scales, or a softening of 

 the bulbs. All seriously-infested bulbs should be destroyed, and the 

 ground where they were grown treated with calcium cyanide. For the 

 treatment of bulbs, they should be immersed for ten minutes in a two 

 per cent, solution of formalin heated to 122 deg. Fahr., or simply in 

 water at a temperature of 131 deg. Fahr. 



Another group of mites of importance to the horticulturist is that 

 of the blister mites; they are so minute measuring about a hundred- 

 and-fiftieth of an inch long as to be invisible to the unaided eye. 

 Though so minute, however, their damage to foliage is characteristic 

 and conspicuous, so that their presence is easily detected. The most 

 important blister mite in New Zealand is the pear-leaf blister mite 

 (Eriopliyes pyri) ; it differs from the other mites described above in 

 having a long and cylindrical body, with only two pairs of legs crowded 

 at the head end, the elongate abdomen having the appearance of being 

 composed of innumerable segments (Fig. 13, 11). This mite lives in 

 colonies in blisters formed on the leaf, and sometimes on the leaf 

 petioles. In the spring the yellowish-green blisters will give the upper 

 surface of an infested leaf a spotted appearance, and as the season 

 advances these blisters become reddish and finally brown : in the case of 

 severe infestation, the blisters become so crowded as to merge into 

 masses. 



During the winter the mites lie in the shelter of the bud scales ; as 

 soon as the foliage begins to develop in the spring the over- wintering 

 mites attack the leaves, each mite forming a blister, in which it produces 

 a colony of young. The offspring then migrate from the parent blister 

 and form blisters for themselves, and this goes on until autumn, when 

 the last generation of mites migrates for the winter to the shelter of the 

 bud scales. 



Owing to the mites being protected within the leaf blisters, summer 

 sprays are not effective as a means of control, which can be effected, 

 however, by spraying with lime-sulphur in the autumn, when the mites 

 are taking up their winter quarters, and again at bud movement in the 

 spring. 



Woodlice. 



Woodlice are so well known, that but little description is necessary 

 here. However, the following features are of interest. Thev belong 

 to the group of animals known as the Cnistacea, which also includes the 

 crabs; these animals breathe by means of gills, and are usually aquatic. 

 but some forms, such as the woodlice, have become adapted to a life on 

 land. In outline (Fig. 13, 12) the woodlice are more or less oval, with 

 the upper surfaces somewhat arched, and the lower flat; the body i* 

 divided into several segments, which may enable the animals to curl 

 up in the form of a pill. There is a distinct head, bearing a pair of 

 antennae and the mouth-parts, followed by seven large thoracic searments. 

 to each of which a pair of legs is attached; finally, the remaining six 

 segments are more or less crowded together, and constitute the abdomen. 



Since woodlice are terrestrial gill-breathing animals, moisture is 

 essential for them, and it is in moist places that they abound. They 

 depend upon a mixed diet, being carnivorous, as well as herbivorous : 



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