376 AN INTRODUCTION TO ENTOMOLOGY 



yellow bug, marked with black. It measures about 8 mm. in length. 

 There are four longitudinal black lines which extend over the 

 prothoraxand the greater part of the hemelytra (Fig. 432). There is 

 in many individuals a black dot on the cuneus of each hemelytron; 

 and the membrane is also black. 



This insect infests various plants, but abounds most on the 

 leaves of currant, gooseberry, mint, parsnip, Weigela, Dahlia, and 

 rose. It punctures the young and tender leaves, causing small 

 brown spots; but these are sometimes so numerous and closely 

 placed that the leaves become completely withered. It is a widely 

 distributed species, its range extending from Canada to Georgia and 

 westward to the Rocky Moimtains. 



There is only one generation a year. The eggs are laid in the 

 terminal twigs of currant and other bushes in midsummer and hatch 

 the following spring. They are laid in clusters, each 

 containing six or eight eggs; these egg-clusters are 

 forced out of the stem somewhat by the growth of the 

 surrounding plant tissue; and as the projecting part of 

 the egg is white, they can be easily found. 



The methods of control are the pruning and burning 

 of twigs containing egg-clusters, and, early in the season, 

 fil'^^~t> the destruction of the nymphs by the use of kerosene 

 Uneatus. emulsion or some one of the tobacco extracts. 



The tarnished plant-bug, Lygus pratensis. — The 

 tarnished plant-bug is a very common species which is found through- 

 out the United States and in Canada. It is smaller than the preceding 

 species, measuring 5 mm. in length and 2.5 mm. in its greatest width. 

 It is exceedingly variable in color and markings ; its color varies from a 

 dull dark-brown to a greenish or dirty yellowish brown. In the more 

 typical forms the prothorax has a yellowish margin and several 

 longitudinal yellowish lines; there is a V-shaped yellowish mark on 

 the scutelliim; the distal end of the corium is dark; and the cuneus 

 is pale, with a black point at the apex. 



This pest is a very general feeder; it has been recorded as injuring 

 about fifty species of plants of economic value; its injuries to the 

 buds of Aster, Dahlia, and Chrysanthemum, and to the buds and 

 blossoms of orchard-trees, and to nursery stock, are well-known. 

 As yet no practical method of control of this pest has been found. 



The apple-redbug, Heterocordylus malinus. — This species and the 

 following one are sometimes a serious pest in apple orchards. They 

 cause spotting of the leaves; but, what is far more serious, they punc- 

 ture the young fruit, which results either in the dropping of the 

 fruit or in its becoming badly deformed so as to be unmarketable. 

 The eggs are inserted into the bark of the smaller branches late in 

 Jime or early in July; they hatch in the following spring soon after 

 the opening of the leaves of the fruit-buds. The n^inphs are tomato- 

 red in color. They first attack the tender leaves, but as soon as the 

 fruit sets they attack it. The young nymphs can be killed by an 



