292 



STATE BOARD OF AGRICULTURE. 



AFFECTING THE FOLIAGE, 



The Apple-tree Plant-lice. (Aphis pomi, fitchii, and sorbi.)* 



Early in the spring, just as the buds commence to open, they are often attacked 

 by small green plant-lice. At least three species of insects are concerned in this 

 work, and of the three we have two and possibly three in Michigan. Aphis 

 pomi imali) the leaf-louse, comes on a little later in the season than the others, 

 and stays on the foliage all summer, passing through several forms but using the 

 apple and some other plants throughout the season for sustenance. It curls the 

 leaves badly. Aphis fitchii, the most common species with us, appears on the 

 buds as they open and stays through May, by which time winged forms wlil have 

 appeared and migrated to other hosts, among them orchard grass. This liisect 

 disappears from the apple before summer. The third species, sorbi, resr-r.'.il'-^s 

 the second in that it migrates to other hosts after a comparatively short tiuji' 

 on the apple. It also curls the leaves badly. All these lice secrete a sweetish 

 sticky liquid called honey-dew and on this honey-dew a black fungus appears, 

 which sometimes gives the trees a sooty appearance. 



The eggs of these plant-lice are oval in form, black and polished. They are 

 laid on the trunk, limbs and twigs of the tree, sometimes in very great numbers. 

 The interesting stages through which these Insects pass, have been described in 

 other bulletins of this station. 



REMEDIES. 



Unfortunately no sprays have as yet been discovered which will successfully 

 cope with these insects in the egg stage, but promptly applied sprays of kerosene- 

 emulsion or tobacco-water will kill the young lice, especially if applied just 

 after the eggs hatch. The "practice of scrubbing the trunk and larger limbs 

 with lye in the winter season, is of use in this connection though it is imprac- 

 ticable to reach the eggs on the twigs in this manner. 



The Ring-legged Tree Bug. {Brochymena annulata.) 



This insect is included in the present work not because it is likely ever to 

 become serious, but because it is likely to appear from time to time, and occa- 

 eionally to do some slight injury, if we may judge from the past history of this 

 insect in Michigan. The figure will give an idea of the appearance of the 

 creature. It may be killed by a spray of kerosene-emulsion. 



Fig. 8. — The ring-legged Tree-Bug, from Riley & Howard, Insect Life Dlv. of Entomology, U- S. 



Dept of Agr. 



♦The life histories of these lice were carefully worlccd out by Prof. Dwight M. Sander.son, then of 

 the Delaware Exp. Sta 



