188 JOHN D. TOTHILL. 



Quebec, revealed mites. In twenty-one collections from trees in various places 

 in and around the city of Fredericton the mite was found to be present in seventeen 

 cases, in none abundant enough to be controlling the scale, but entirely absent only 

 in four cases. This fairly regular distribution, as at Fredericton, Moncton, and 

 Mount Koyal, seems to indicate the ability of the mite to spread readily from tree 

 to tree. The same ability was indicated by finding the mite on a young thorn bush 

 situated rather more than a hundred yards from the nearest possible source of 

 infestation. 



In New Brunswick scaly twigs were examined from Moncton, Nerepis, St. Stephen, 

 Woodstock, Kingsclear, Fredericton, Chipman and Chatham ; the mite was found 

 to be present at the first six places and absent at the last two. Its presence at 

 Moncton and absence at Chipman is interesting, because these places are a little less 

 than sixty miles apart. 



Finally, as to continental distribution, the mite is known to occur in Nova Scotia, 

 Prince Edward Island, New Brunswick, Quebec, Ontario, Massachusetts, Ohio, 

 Illinois, and Iowa. Efforts to secure the scale from the prairie provinces have met 

 with no success, and in those places — probably owing to the scarcity of suitable 

 food-plants— it is evidently exceedingly scarce, if not entirely absent. A number 

 of good collections of scale material have been examined from British Columbia, 

 but so far the mite has not been discovered west of the Eocky Mountains. Europe 

 seems to have been the original home of the mite. To what extent it has followed 

 the oyster-shell scale in its now almost world-wide distribution remains to be 

 determined. 



So far as I am aware, Hemisarcoptes has been recorded feeding only on oyster-shell 

 and San Jose scales, and my own observations are confined to its work on the former 

 in Canada. 



As soon as the eggs of the scale are deposited the mite begins to feed upon them. 

 By glueing scales to cover-glasses and placing them over cells it was possible to observe 

 the process of feeding. In one case a mite was noticed at 12.30 p.m. with the short 

 proboscis partly sunk into the side of an egg ; it was upside down and evidently 

 bent on a meal. During the extremely slow, and from the spectacular point of view 

 rather uninteresting, process of feeding the only movement noticed was a slight 

 working of the fore legs as though to insert its mouth-parts further. At the point 

 of contact the egg had caved in just a little. The mite disengaged itself at 2.30 p.m. 

 and did not seem to be in a gorged condition, although I have seen some that were 

 greatly distended after a meal. The only effect immediately noticeable on the 

 egg was the slightly caved-in area at one side and the tiny hole made by the chelicera, 

 but after a few days the egg began to turn brown and to collapse. In the case of a 

 larger mite the caving in at the point of feeding was much more marked, and as early 

 as the next day the egg had entirely collapsed. On 25th December a mite feeding 

 on an egg had swollen up so as to give the appearance of being as tight as an average 

 drum ; and the egg had collapsed in the neighbourhood of the chelicera. In these 

 laboratory experiments some of the mites would not feed at all and others seemed 

 to feed ravenously : in one case six mites ate twenty-four eggs in ten days ; in 

 another a large mite ate seven eggs in eight days. 



