640 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



Michigan and Illinois, in which States it has done considerable 

 injury. The psyllas are' nearly related to the plant-lice and are 

 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 presence 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 



FIG. 495. The pear psylla (Psylla pyricola Foerst) : adult, full-grown nymph 

 and egg all greatly enlarged in different proportions. (After S'inger- 

 land.) 



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 drop 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. 



