INSECTS INJURIOUS TO THE APPLE AND PEAR 567 



sometimes called jumping plant-lice, on account of the habit of 

 the adults of giving a quick jump and flying from the foliage 

 when disturbed. Like the plant-lice they reproduce very rapidly 

 and suck the juices from the foliage and fruit. Usually the first 

 indication of the pest is the prescence of large quantities of honey- 

 dew, secreted by the nymphs, with which the foliage becomes 

 covered, and which attracts numerous ants. When the psyllas 

 are numerous the leaves and fruit become coated with this sticky 

 substance and it even drops from them like rain and runs down 

 the trunk. A blackish fungus grows on the honey-dew and is 

 always a good indication of the presence of the psylla. 



Badly infested trees are so injured by loss of sap that they 

 shed their leaves in midsummer, the lower ones being the first 

 to turn yellow and drop. The young fruit also drops from badly 

 infested trees, which make but little growth, as the young shoots 

 are often attacked and wither early in the season. 



The adult psylla is about one-tenth inch long, of a reddish- 

 crimson color with brownish-black markings, bronzy eyes and 

 dark wing-veins, looking very much like a miniature cicada or 

 dog-day harvest-fly. 



Life History. The adults hibernate over winter in crevices 

 of the bark and there lay their eggs late in April or early May 

 on the twigs or around the buds. The egg is about one-eighteenth 

 inch long, hardly perceptible without a lens, and orange-yellow 

 in color. It is pear-shaped with the small end drawn out into 

 a long thread, and the larger end is attached to the bark by a 

 short stalk (Fig. 502). The later generations deposit the eggs 

 on the leaves often in rows or bunches. The eggs hatch in two 

 to three weeks and the young nymphs feed on the leaf petioles 

 in the axils of the leaves and later on the leaves, young fruit and 

 tender shoots, from which they suck the sap. The nymph is a 

 peculiar-looking little bug, broadly oval, flattened, of a yellowish 

 color, with crimson eyes, but later becomes reddish with black 

 markings and conspicuous black wing-pads, as shown in Fig. 502. 

 They move very slowly and are frequently quite covered by their 

 own honey-dew. After molting some four or five times, they 

 finally transform to adults in about a month. According to 

 Slingerland there are four generations in New York and probably 

 five in Maryland. 



