16 



THE TUUP SOFT SCALE. 



Lecanium tuUpifercB, Cook. 



The tulip, Liriodendron tulipiferm, is deservedly a popular shade 

 tree in many localities, and is, as a whole, fairly free from insect 

 injury. Plant lice attack it in some localities and this soft scale has 

 increased to such an extent as to seriously threaten the smaller trees. 

 The scale, as it appears in midsummer and later, is almost hemi- 

 spherical, nearly a quarter of an inch in diameter,. gray in color, slimy 

 to the touch and repulsive to the eye. It crushes easily when handled 

 and the body contents have a deep purplish color, with an odor that is 

 distinctly offensive. It is the largest of its tribe in New Jersey and 

 BO disagreeable that many persons have preferred to cut down their 

 trees rather than attempt to deal with the insect. 



The female scales grow until late August, and in early September 

 are mature and ready to reproduce; young then appear beneath the 

 body in great numbers. They are minute, black, somewhat flattened 

 above, oval in shape and have the body segments clearly marked. 

 Thousands of these larvse swarm in early September on and near the 

 infested branches, setting so close together that they conceal the 

 bark completely and give it their own dull, black tint. 



They begin feeding at once and make some growth before cold 

 weather sets in, being at that time almost one-sixteenth of an inch 

 in length, jet black and quite visible to the naked eye. The adults 

 dry up and many of them drop or are washed o3 during the winter, so 

 that most are gone when spring again comes around. At that time the 

 larvEe resume growth, and become large enough to attract attention 

 in June. Late in July the insects are sexually mature and the life 

 cycle is complete. 



This species is kept in check by a small caterpillar that feeds upon 

 the young. In September, when the female scales are reproducing, 

 we often find, under the scale, a little reddish caterpillar which lives 

 in a web and feeds greedily on -the larvje. Sometimes every scale on 

 a twig shelters one of these caterpillars, which make galleries from 

 one point to another, occasionally forming masses of silk that hold 

 together all the scales on one twig. Unfortunately, these caterpillars 

 cannot eat the larvae as fast as they are produced, and a considerable 

 number always escape to set upon the growing twigs. 



