STATE HORTICULTURAL'' SOCIETY. 163 



APPLE BARK MCE. 



Usually known as Aspidiotas Harrisii and A-ij). Gonchiformis , are more despised, 

 especially the latter, by the horticulturists of this and other Northern States than any 

 or all other species of bark lice among us. The formei- 1 Iiavo known from my youth 

 up; it was pointed out to me when a small boy liy my father on the fruit trees, pear, 

 apple, etc., on the farm where I was raised, in Chester county, Pennsylvania, It was 

 somewhat abundant, and injurious on young trees, bit not to be compai-od with the 

 latter in Northern Illinois. This has been called the American or '■' Wldte Barh lov.se,'' ' 

 l^ecause of its l)road, flat, grey scale. This scale serves to protect a few purple eggs 

 during the winter. I do not find this any more numerous there now than lio or 30 

 years ago, and only on the young trees. On the old moss-covered trees that w^ere 

 planted long ago, some of them probably before the revolutionary war, I could find 

 no bark lice. Four years ago I saw there some of the imported or " Oyder-sJiell larlc 

 lice'' ' on young apple trees imported from New York State. When I again visited my 

 old home last May, I did not observe any increase in this insect on these same young 

 trees. I saw a few on an old tree in a neighbor's orchard, ami on a seedling l)y the 

 roadside, one-fourth of a mile from any other apple tree.^ Why this failure to 

 increased May it not be because the climate is too warm and damp? Our imported 

 oyster-shell bark louse has long been arranged under the coccus family. The coccids 

 are scale-Wke insects, either moralle or immoruUe, and the iars-uslvAa one joird ^r\(\one 

 claiv, according to the construction of the family, as arranged tor us by the old 

 authors. But after studying this bark louse in the most careful manner, I found that 

 it was not a scale-^«^-c insect any more than is a common meat-maggot, Ijut that it is a 

 scale-luilding insect. It lives inider its scale, which is its house of covering or pro- 

 tection, and there lays its eggs in autumn, and the same scale that had protected the 

 body of the mother during the sununer, protects the eggs during the wiulcr. the 

 mother having dried away to a small particle in the anterior part of the scale — the 

 eggs, occupying the greater part of the cavity beneath the scale. (Mr. Riley also 

 observed this fact simultaneously) . All previous authors believed that the scale-like 

 shield was the actual body of the mother, and liy studying dry specimens, coidd not 

 well come to any other conclusion. Therefore the eggs beneath the scale were sup- 

 posed yet to be in the body of the dead mother. If they had studied their specimens 

 in the living state as I did for the purposes of gaining practical and unmistakable 

 information, they long ago would have obtained the same results as I made public on 

 the first of November, 18G7. 



On studying the newly hatched young bark louse with a microscope, the only state 

 in which they are found with legs, I find the one-jointed tarsi without claws — witliout 

 even the trace of a claw. After such revelations, how could I retain it in the coccus 

 family where the insects are all declared to be scale-like and the tarsus has one clawJ' 



The Homoptera are arranged under three sections : 



1. Finera. — Tarsi 3-joiuted. 



2. Bimera. — Tarsi 2-jolnted. 



3. Monomera. — Tarsi 1-jointcd. — Westwood's Introduction, Vol. 2, p. 419, 



This last section {Monomera) heretofore has embraced only the Coccidae, Tarsi one- 

 claw. When I studied the vitifoliae insect on the grape leaf, and in connection, part 



