Insects Injurious to the Apple. 



155 



■often until the fruit is ripe or even the leaves are falling. Furley (6) 

 records that the dead leaves showing Psylla skins remain on the 

 trees up to Christmas, and in several orchards tliey were noticeable 

 up to March. 



This brown appearance has given rise to an idea that the blossom 

 has been struck by frost. That it is Psylla work we can tell by the 

 presence of the small insects in the trusses, and later by their dried 

 grey skins or exuviae which remain attached to the strigs and leaves 

 until the end of the season (Fig. 130). These are mostly pupal skins. 

 It is probable that some of the supposed damage by Sucker is due to 

 the Brown Eot Fungus. 



Not all varieties are similarly affected. The Ecklinville may be 

 pointed out as suffering more than any other, possibly owing to the 

 stalks of the blossom being so short. The Blenheim Orange, the 

 Wellington, Lord Grosvenor, Lane's Prince All)ert and Quarenden 

 we have seen quite ruined by this pest, but in all parts the Worcester 

 Pearmain appears to suffer least. 



LiFE-HlSTOKY AND HaBITS. 



The adult Psylla mail (Fig. 128) is winged in both sexes. They 

 •occur from the middle of May till the middle of November. The 

 colour is very variable. 



At first they are greenish-yellow to green, the legs paler and the 

 feet blackish ; later they 

 change, some become 

 brownish-yellow, others 

 show dark markings, 

 with even red and 

 yellow. The wings are 

 quite transparent and 

 have greenish or green- 

 ish - yellow veins, and 

 they fold over the body 

 in tectiform manner 

 when the insect is at 

 rest. 



In length they vary from -^^ to \ inch. The venation of the 

 wings is very characteristic and will at once separate this insect from 

 other fruit " Leaf Hoppers " with which they may be confused 

 owing to their jumping habits. At the least shock they skip off the 

 foliage and then frequently use their wings and may be seen taking 

 short flights under and about the trees. The males, according to the 



FIG. 128.— ADULT APPLE t<VCKYA\ (I'sylla mali). (Xl4.) 



