AND OTHER INJURIOUS INSECTS OF I907 AND I908. IO3 



THE COTTONY MAPLE SCALE, 



Piilvinaria inniimerabilis Rath. 



This pest, so common on Maples, and in some instances on Elms, 

 has been and is injuriously abundant. It has been thoroughly dis- 

 cussed in previous publications from this department, but as it figures 

 prominently as one of our Shade Tree Pests, we include here a short 

 account of it, and suggest certain treatment. This, with the accom- 

 panying illustrations, should give our readers a very good idea of its 

 appearance, and the methods by which it can be combated. 



Our illustration shows this insect, which has been extremely 

 abundant on Soft Maple. Maples and Elms as well as various vines 

 and shrubs in St. Paul, Minneapolis, St. Anthony Park and many 

 towns throughout the state, as well as trees in localities in South Da- 

 kota and elsewhere, have been more or less affected. 



The spreading from tree to tree could be affected, where trees 

 interlace, by the active young crawling from limb to limb, and further 

 by being carried on the feet of birds. In the opinion of the writer, 

 the English sparrow is, in a large measure, responsible for this, for 

 he is pre-eminently now tlic bird of the city and village streets. We 

 must not, however, overlook the agency of insects of various sorts, upon 

 whose bodies the young lice could be easily transported. Prof. Riley, 

 in the first IMissouri Entomological Report, comments on this and says, 

 "The copious secretion of honey dew attracts many honey loving in- 

 sects, such as bees, wasps and flies, and these without doubt carry 

 many of the restless young larvae from tree to tree." Spiders, also, 

 are said to assist in this work, and even the beneficial "Lady Bird" 

 beetles which prey upon the scale. The wind, too, in blowing infested 

 leaves or twigs from one place to another, also plays a part in dis- 

 tributing this insect. 



Ordinarily a strong, vigorous tree can withstand considerable 

 sapping of this sort without being appreciably weakened, but when 

 the pest is as abundant as it has been recently, their pernicious work is 

 bound to show, in the sickly appearance of some of the branches of 

 the maples. 



Remedies: // trees are triniined in Zi'iiiter or early spring^ and 

 the cuttings burned, the adult scales on the cuttings, zvith many thou- 

 sands of eggs, zvill he destroyed. The same result zvoidd he ohtained 

 hy pruning ami burning in the late summer and fall. Sprayings of 

 kerosene emulsion in the spring and early summer will kill the young 

 lice as they are crawling over branches and leaves, and strong caustic 

 sprays, sucli as lye, or lime and sulphur, applied in unntcr when the 



