88 Plant- Lice and Scale-Insects. 



Our best-known representative of the Psyllidce, or jumping-plant-lice, is 

 the species causing what is called the pear-blight. They are distinguished 

 by long thread-like antennae of ten joints each, terminated by two setae, or 

 bristles, and their power of leaping many times their own length. When 

 examined under a low magnifying power, they curiously resemble a minia- 



ture cicada, or harvest-fly. At this date (June 15) they may be found in con- 

 siderable number upon the young leaves of the pear-tree, in both the pupa 

 and imago stages; and the result of their punctures is already making itself 

 manifest. Persistent syringing or showering the trees with soap-suds is an 

 infallible remedy. Fig. 2 represents the perfect insect or imago of Psylla 



Fig. 2. J 



pyri (Harris), magnified about ten diameters. The colors are light yellow 

 and black, or dark brown ; wings hyaline, save the stigma seen below at s, 

 which is yellowish, and the oblong blackish spot on the inner margin of 

 each wing : the antennae are light, excepting the apical joints ; and the feet 

 are varied with blackish. Fig. 3 represents the same insect with the wings 

 expanded ; and Fig. 4 the pupa, which is active, and readily distinguishable 

 from the larva by the wing-scales, w. 



The Coccidce, or scale-insects, sometimes called mealy-bugs, present some 

 anomalous features. As larvae, they are well formed, furnished with feet, 

 antennae, and sucker, with the segments of the abdomen well defined. As 

 they approach the adult state, these organs disappear, the distinction of 

 parts is lost, and the animal becomes a mere shapeless mass, finally dry- 



