The Currant Plant-louse 335 



small, but easily recognized by the shining vermilion-red color oi 

 the body, marked by blackish spots on the thorax. The mature 

 insect is a bright orange-yellow colored bug, three-tenths of an 

 inch long, with four black stripes extending down the back. 



The eggs are laid in clusters in slits near the tips of twigs of the 

 present year's growth of currants, gooseberries, and other shrubs. 

 They are deposited late in June, and remain in this position until 

 the nymphs hatch the following spring. These undergo five moults 

 before reaching the adult form. The adults disappear early in July, 

 there being but one brood a year. 



Remedies. Since the insect feeds by sucking the sap of the plant 

 from the inner tissues of the leaf, the application of poisons like Paris 

 green can do no good. Kerosene emulsion, diluted with not more 

 than five parts of water, if very thoroughly applied while the insects 

 are still young, will prove effective. The egg clusters are not diffi- 

 cult to find, and since they remain over winter, trimming off and 

 burning five or six inches of infested twigs is a practicable remedy, 

 at least on a small scale. 

 Reference. 



Cornell Univ. Expt. Sta. Bull. 58. 



THE CURRANT PLANT-LOUSE 



Mysus ribis, Linn. 



This is a small, yellowish plant-louse, appearing on the under side 

 of currant leaves, causing them to curl and present a blistered and 

 generally reddish appearance on the upper surface. The shining 

 black, cucumber-shaped eggs are attached to the bark of the new 

 growth and hatch soon after the leaves open. The lice hatched 

 from these eggs are all females and are called stem-mothers. When 

 mature they give birth to living young. These in turn, and through- 

 out the summer, are all females and are born alive. Until food be- 

 comes scarce nearly all are wingless, after which winged females are 

 produced which migrate to other feeding grounds. As the lice become 

 abundant they often cover the entire under side of the leaves, causing 

 them to become very much curled and distorted. These leaves may 

 fall later, preventing the fruit from ripening as it should. The fruit 



