52 THE REPORT OF THE No. 19 



1250 Aspidiotus Osborni, (Newell and Ckll.) — Quercus alba, Betula lutea — 



Guelph, Toronto. 

 1252 Aspidiotus ostreaeformis, (Curt.) — Apple, Pyrus, Maple, (Acer sacchari- 



num, Hawthorn, Ontario. 

 1256 Aspidiotus perniciosus, (Comst.) — Apple, Pear and many shade trees — 



Niagara district, London, Aylmer, Essex district. 

 1270 Aspidiotus ulmi, (Johnson) — Ulmus americana — Guelph^ Toronto. 

 1300 Chrysomphalus dictyospermi, (Morg.) — Cinnamon, greenhouse, Ottawa. 

 1305 Chrysomphalus obscurus, (Comst.) 

 1330 Targionia Dearnessi, (Ckll.) — Arcostaphylos uva-ursi, Bruce Peninsula, 



Shores of Lake Huron. 

 1377 Lepidosaphes Beckii, (Newm.) — imported oranges and lemons. 

 1431 Lepidosaphes ulmi, (Linn.) — many species of trees, Ontario. 

 1442 Parlatoria Pergandei, var. these, (Comst.) — lemon, O.A.C. greenhouse. 



The San Jose Scale, Aspidiotus perniciosus, (Comst.), figs. 10-14. 



Wherever it occurs the San Jose Scale is considered, and rightly so, the 

 most destructive insect that fruit growers have to combat. Fortunately for 

 us, however, in Ontario it is confined to the south-western portion of the pro- 

 vince. 



The mature female scale is small, circular, 1-2 mm. in diameter, only 

 slightly convex, grayish brown in color except the central part, which is often 

 of a lighter shade, being usually a light yellowish-brown color. The exuvise 

 or larval skin is centrally situated, or nearly so. The surface is fairly smooth. 

 Somelimes a sooty fungus {Furaago salicina) darkens the color of the scale. 



The male scale is much smaller and different in shape. It is oblong in- 

 stead of circular, and about twice as long as broad, but the total length is 

 only about half the diameter of the female. The exuvial part is not central, 

 but situated near one end. The color as a rule is considerably darker than 

 that of the adult female. 



The usual appearance of the wintering stage of the female scale is differ- 

 ent from the summer form, being very small, almost black and circular, with 

 exuvial part central. There is a distinct nipple with a ring or depression 

 around it. 



There are four other Aspidiotus scales found in Ontario which are very 

 difficult to distinguish from the San Jose scale. The particular points of 

 difference between each of these and Che San Jose scale will be discussed as 

 these scales are respectively taken up. It should be noted, however, that if 

 one takes his knife and cuts off a slice from a twig or branch affected with 

 San Jose scale the cambium and some of the sap-wood just beneath the bark 

 will be seen to be colored purple. This purplish color is very often seen 

 also on the surface of the bark, and on the fruit around where the scale is 

 situated. 



Though the scale insects are in all stages when winter comes on, yet by 

 far the majority of the females are of the type described above under the 

 heading of the wintering stage. In the spring, about the end of May, though 

 this year not until the middle of June, the winged males come forth and fer- 

 tilize these half-grown females. About a month after this, the latter begin 

 io give birth to living young. About eight or ten young are born in a day 

 as a rule, and a single female continues to reproduce at this rate for about 

 six weeks, when she dies. A young female takes about forty days to mature 

 and then in turn begins to produce living young. In Ihis way we find that 

 all stas-es of the insects are to be found all through the summer until the frost 

 stops the reproduction. So very prolific is the insect that it has been cal- 

 culated that if every scale were \o live and mature, 3,000,000,000 individuals 

 could be traced back to a single fertilized female in one summer. Hence H 



