INSECT PESTS OF OHIO SHADE AND FOREST TREES 301 



effective but the miscible oils applied at the rate of 1 part to 15 

 parts of water are entirely satisfactory. The work should be done 

 just before the buds break in the spring, 



THE TULIP TBEE LECANIUM 



{Toumeyella Uriodcndri Gmel.) 



Deseription. — The tulip tree lecanium is one of the very largest 

 of the group of fleshy scales. When permitted to develop without 

 crowding, the adult female is hemispherical in shape, about one- 

 third of an inch in diameter and of a rich dark brown color. How- 

 ever, the scales usually are found in clustered, crowded masses, 

 whereupon they become very much distorted and misshapen. (See 

 Plate LIII, Fig. 2.) 



Life history and habits. — The small, flat, inconspicuous imma- 

 ture scales (See Plate LIII, Fig. 1) pass the winter securely attached 

 to the twigs of the host. Development is rapid after tree growth 

 starts in the spring and the young, as recorded by Professor Cook 

 in Michigan, appear in late August. There is but one brood 

 annually. 



Nature of work. — Many instances have come to the writer's 

 attention where entire trees were in a dying condition because of 

 the work of this insect and it is much more common to find dead 

 branches, particularly the lower ones dead from this cause. An 

 incidental form of damage is the choking of the stomata because 

 of the profuse discharge of honey-dew and the attending growth 

 of mold. Further this honey-dew falls upon sidewalks and the 

 moldy growth renders the walks particular untidy. Finally the 

 honey-dew attracts myriads of insects which contribute still further 

 to the discomfort of pedestrians and nearby residents. 



Food plants. — The tulip or yellow poplar {Liriodendron tulip- 

 fera) is the principal host of this species. The scale has been re- 

 corded, however, upon magnolia. 



Distribution. — The tulip tree lecanium is distributed through- 

 out Ohio, both as a city and forest pest. In some of the remote 

 woodlands of southern Ohio the writer has found it in severe in- 

 festations and has encountered it occasionally infesting forest 

 plantations. The tulip scale has been recorded also from Massa- 

 chusetts, Connecticut, New York, New Jersey, Tennessee, Western 

 States and Europe. 



Natural enemies. — But one parasite, Coccophagus flavoscutel- 

 lum, Ashm., has been recorded for this species. The lady-beetle, 

 Hyperespis signata binotala, was observed at Mineral, Ohio, July 

 12, 1916, associated with this scale. 



