186 STATE HORTICULTURAL SOCIETY. 



Many evidences of seemingly miraculous escapes of plant life 

 from destruction during severe winters, when closely examined, have 

 strengthened me in my belief, and a few years hence I hope to be able 

 to present the results of experiments now being made in the line 

 indicated: Chas. Teubner. 



ENTOMOLOGICAL NOTES FOR 1892. 



The Wooly Aphis or Apple-root Louse (Schizoneura lanigera). 



Many complaints reached me during the past summer of the pre- 

 valence and destructiveness of this insect, especially to young orchards 

 where the soil or subsoil was of a loose or gravelly nature. Such soil 

 does not pach so closely about the roots of the trees, and naturally 

 forms the cavities and galleries which facilitate the development and 

 multiplication of the pest. On clay or any tenacious loam, wet weather 

 greatly reduces their number, or forces them to the surface, where they 

 are more easily treated, but on porous soils they are not injuriously 

 affected by moisture. 



This aphis is said to be of American origin, but as it occurs all 

 over Europe, and as there is no record of its discovery on the roots of 

 any wild apple or thorn, in unsettled regions, it is far more probable 

 that it is an immigrant. As is well known, it forms its colonies both 

 above and beneath the surface of the ground, those on the apple-roots 

 being by far more destructive and difficult to extirpate than those 

 occurring on the trunk and branches. The full-grown insect is one- 

 tenth inch long, flask-shaped, of a dull yellow or purplish color, and 

 chiefly characterized by the line, bluish-white " wool" or cottony fila- 

 ments, that more or less envelop it, and not only protect it from mois- 

 ture, but form a convenient nidus for the young. 



In common with most plant lice, this species multiplies agamically 

 — innumerable generations being born alive by a sort of budding pro- 

 cess without the intervention of the male element. The young are 

 produced at the rate of four or five a day and are all females, which in 

 the course of a week or ten begin themselves to add to the popula- 

 tion. When the tree attacked is so weakened that the supply of sap 

 begins to fail, a considerable proportion of the aphides acquire wings 

 to fit them for migration, and in this way they spread rapidly through 

 an orchard or district. The majority of these winged forms occur 

 from the aerial colonies, but some make their way out from the root- 

 feeding form. As a rule, the vitality of the species is renewed by an 

 annual brood of true males and females, the former of which are inva- 

 riably, and the latter usually, endowed with wings. These perfect 



