. Annual report. Entomological Society of Ontario; Insect pests; Insects. SOCIETY OF ONTARIO 49 Claricincllae. o Cl tt) 60 crt so 2 40 s ^° CL May 1 1945 ^^^^^^^^^ November J 1944 J November I L ,U. 1 r 1 1 —I 1 1 1 1 1—•—1 p 1 Miles distant from liberation point The parasitism at different distances from the liberation point during the years 1944-1948 is shown in Fig. 1, which shows graphically the changes in density and dis- persal of the two species of parasites. It is evident from the figure that the casebearer infestation was controlled each year in a progressively larger area o
. Annual report. Entomological Society of Ontario; Insect pests; Insects. SOCIETY OF ONTARIO 49 Claricincllae. o Cl tt) 60 crt so 2 40 s ^° CL May 1 1945 ^^^^^^^^^ November J 1944 J November I L ,U. 1 r 1 1 —I 1 1 1 1 1—•—1 p 1 Miles distant from liberation point The parasitism at different distances from the liberation point during the years 1944-1948 is shown in Fig. 1, which shows graphically the changes in density and dis- persal of the two species of parasites. It is evident from the figure that the casebearer infestation was controlled each year in a progressively larger area of which the liberation point constituted the centre. This progressive movement of higher para- sitism from the centre, however, did not begin until the degree of parasitism by A. pumilis became very high at, or near, the liberation point. Thus, in 1944, when the dispersal of A. pumilis was first recorded, parasitism reached 90 per cent at the liberation point, whereas two miles distant it amounted to only one per cent. In 1945 the parasitism by A. pumilis, now 40 per cent at the liberation point, had increased to 19 per cent at a distance of 12 miles. At the same time, C. laricinellae began to appear at a point two miles distant, following the presence of A. pumilis at the same point in the previous Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Entomological Society of Ontario; Ontario. Dept. of Agriculture. Toronto, The Society
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectinsects, bookyear1872
