CHERRY LOUSE 129 



bunches of branching spines, tipped with black. These spines are 

 capable of inflicting a painful wound on tender skin. 



The caterpillars feed not only upon cherry but also upon 

 apple, willow, elm, poplar, oak, currant, clover, etc. 



Control. If troublesome, the species may be easily controlled 

 by hand-picking. Gloves should be worn for this work. As 

 stated elsewhere, a spray of arsenate of lead controls all leaf- 

 eating forms of bisects without injury to the most tender tree. 



The Pear and Cherry Slug. This insect in its immature form 

 is a small, dark green, slimy slug (Eriocampoides limacina Ratz). 

 It later turns into a black, four-winged 

 insect known as a saw-fly (Fig. 151). 



Life History. The female lays eggs 

 in the tissues of the leaves, at inter- 

 vals during the summer, giving rise to 

 several broods of slugs. This slug, when 

 first hatched, is whitish. There are ap- 

 parently four moults . After the last moult 

 it loses its slimy appearance and becomes 

 yellowish hi color, crawling or falling to 

 the ground and forming a pupal chamber 

 three or four inches below the surface, FlG ' 151 -~ cherr y alu on leaf - 

 emerging as an adult, four-winged saw-fly in two or three weeks. 



Injury. This slug feeds on the upper side of the leaves of 

 cherry, plum, etc., causing the foliage to wither and appear 

 scorched as by fire. 



Control. Spraying with a weak solution of arsenate of lead 

 will prove effective. Use one pound to fifty gallons of water. Or 

 use white hellebore, one ounce to three gallons of water. Air- 

 slaked lime or even road dust thrown on this insect is fatal. Trees 

 protected from other insects by arsenical sprays would not be 

 injured by this pest. 



The Cherry Louse (Myzus cerasi Fabr.). -These are black, 

 shiny plant lice, working upon the young shoots and tender foliage 

 of cherry trees. 



Description and Life History. Like other plant lice, they 

 multiply with great rapidity, giving birth to living young during 

 the summer. Also, like other members of this group, they 

 secrete a sticky honey dew which attracts ants, wasps, and 

 two-winged flies. Winged generations appear during the summer. 

 The last generation in the fall usually produces winter eggs. 

 These, in turn, hatch into " stem-mothers," which, in the following 

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