INJURIOUS INSECTS. 141 



-dark blotches, which have soinethnes appeared iu the handsome 

 foliage of the tulip trees, caused by larvae of a small, mosquito- 

 like fly {Cecidomyia liriodendri) . At the Arnold Arboretum and 

 other places, alders have been annually stripped of most of their 

 leaves by the larvte of a small sawfly {Fenusa varipes), which 

 have been so numerous as to completely clean out the interior of 

 the leaves, leaving only the dry skeletons and skins, which wither 

 and fall in midsummer. 



Pale colored lines, sometimes zigzagi and irregular — sometimes 

 following the margins or veins of the leaves, are often found on 

 cinerarias, enpatoriums, Paris daisies or marguerites, and similar 

 plants in the garden and greenhouse. These are caused by the 

 larva? of very small, dark gray flies, which live within the leaves. 

 Infested leaves should be removed and destroyed whenever seen, 

 or if the leaves are few and not badly injured, and it is desirable 

 to retain them, they may be held up to the light, when the little 

 larvae can be easily seen at the ends of their tunnels, and crushed. 



These pests have sometimes done much damage to the foliage 

 of cinerarias, enpatoriums, and other composite plants iu green- 

 houses iu this region. They are liable to affect chrysanthemum 

 leaves. Leaf-mining insects, being secure from insecticides, are 

 not easily dealt with. Hand-picking and burning of the infested 

 leaves is the usual remedy advised. 



The foliage eaters among insects probably attract the most 

 general attention. In this part of the country there are three or 

 four species better known than all others. These are within 

 fairly easy control and it is due to our own carelessness if we 

 allow them to increase to a very injurious degree. It would seem 

 as though their habits must be too w^ell known to require mention, 

 but numerous questionings show how little they are understood. 



The Tent Caterpillar (^Clisiocampa Americana)^ so common in 

 spring and early summer, may be easily located by the tent-like 

 web in w^hich the caterpillars live when not out feeding. They 

 may be found in then- webs in the early and late parts of the day, 

 and on cool cloudy days, and are then most easily destroyed. 

 During the warm part of the day they may be scattered on the 

 foliage ; then collecting them is more difficult and uncertain. 



In midsummer the moths deposit their rings of eggs on the small 

 twigs, upon which they remain until they hatch in the following 

 spring. These rings of eggs are fairly large, and sufficiently con- 



