OYSTER SHELL BARK LOUSE. The Oyster shell bark louse, (Aspidiotusconchiformis,) is often destructive to young orchards if neglec ted, fastening themselves in countless numbers on the young bark of the twigs and smaller limbs, and thus sapping the life of the tree by sucking its juices. This is an imported species, not origi nally a native of America. The native bark louse (A. Harisu) does comparatively little dam age. The cut shows the manner in which the insect attaches itself to a limb at a, natural size; b, and c, show the insect highly magnified, the former a dorsal, and the latter a ventral view. Dr. Riley renamed this insect in 1873 Arytilaspis ponzicortis, retaining the popular name, although the case under which the insect lives is usually rnore of the form of the mussel than the oyster. Once the insects are firmly fixed to the bark under their covering, remedies,. except slowly scraping them away are of but little value. The proper time to attack them is in June, or at the time when the young hatch, and crawl forward to seek new quarters. Then any alkaline wash or strong soap suds readily kills them. They are active, however, but a few days, and should be closely watched. Fortunately they have
many parasitic enemies, so that with a little attention at the right season they are easily kept down, and once an orchard is cleared, it is gener ally for good, unless infested trees are planted in, for as is well known they are incapable of moving far, unless carried. Harris says the body of the female insect, which is covered and concealed by the outer case, as shown above, is minute, of an oval form, wrinkled at the sides, flattened above, and of a reddish color. By means of her beak, which is constantly thrust into the bark, she imbibes the sap, by which she is nourished; she undergoes no change, and never emerges from her habitation. The male becomes a chrysalis or pupa, and about the mid dle of July completes its transformations, makes its escape from its case, which it leaves at the hinder extremity, and the wings with which it is provided are reversed over its head during the operation, and are the last to be extricated. The perfect male is nearly as minute as a point, but