348 



Bulletin No. 112. 



[January, 



surfaces of the leaf, but most abundantly beneath, or else may locate 

 upon the twigs. At this season (Fig. 3) they present the appear- 

 ance of small, inconspicuous, waxy, elongate-oval scales, applied 

 closely to the leaf. They are usually motionless, but have never- 

 theless minute 

 legs still capable 

 of service, but in- 

 visible unless the 

 insect is turned 

 over. Inserting 

 their tiny beaks 

 into the tissue of 

 the leaf, they suck 

 out the sap, and 

 when the supply 

 of food is large 

 they give off the 

 excess in the form 

 of a sticky fluid, 

 the so-called 

 "honey dew," 

 which moistens 

 the surface of the 

 lower, leaves and 

 falls on the plants beneath the tree. Under this 

 large and constant withdrawal of sap the leaves 

 turn pale or yellowisb, and may fall off prema- 

 turely, with the effect sometimes to kill the larger 

 branches or even the entire tree. 



The male bark-lice beneath the scales on the 

 leaves reach maturity the same season, and trans- 

 form to tiny gnat-like insects (Fig. 4) with a 

 pair of delicate wings. They pair with the partly 

 grown females on the leaves, and die at the ap- 

 proach of winter. Before the fall of the leaf in 

 autumn the young females collect on the under 

 side of the smaller branches, where they spend 

 the winter in a more or less dormant condition 

 with their beaks inserted in the wood. They 

 complete their growth in spring (Fig. 5), and 

 in due time produce the so-called "cotton," within 



Fig. 4. Male of Cottony Maple Scale: a, adult; b, c, an an- 

 tenna and leg enlarged ; d, e, second stage of pupa and its cast 

 skin; /. g, true pupa and its cast skin. All greatly enlarged. 

 (Howard, D. S. Department of Agriculture.) 



Tig. S. The Cottony 

 Maple Scale: adult fe- 

 male in spring, just 

 before ) the formation 

 of the cottony egg-sac. 

 (Howard, U. S. De- 

 partment of Agricul- 

 ture.) 



which the eggs are imbedded. 



