58 Indian Museum Notes. [Vol. W 



showing that, with this pest, leaving the ground uncropped for a time, would be of 

 no service in clearing the land of the infestation, as it is with various other of our 

 field attacks, The experiment with the castor-oil seed-cake, showing its harmless- 

 ness to wire-worm life, is also a valuable record, both as a scientific fact and also 

 as a reliable authority to turn to, which may save unnecessary outlay, and also 

 some disappointments in field experiments as to preventive treatment for wire- 

 worms." 



5. Pear Gnat Midoe. 



Genus Diplosis. 

 Prevention and remedy. 



"The Gnat or Midge, which causes the injury, is a very small two»winged flyV 

 gnat-like in appearance, and about the twelfth of an inch or rather more in 

 length. 



" Gathering and destroying infested fruit has had very good results, so has 

 removal of the infested surface, or digging it in ; and this stands in contrast to 

 conditions of trees on pasture land, whree, of course, the infested surface could not 

 be removed. 



" Kainite, so strongly recommended in United States of American Practice, has 

 answered well ; and there is a good note of successful use of woodashes. No 

 special benefit appears to have followed use of lime or of nitrate of soda. A few 

 notes are also given of kinds of Pears which are considered less or more subject 

 to infestation, with some remarks on what is conjectured to be the reason of this 

 circumstance. 



"The little maggot-infested Pears, should, if possible, be picked from the trees 

 before the maggots leave them to go down into the ground, and should be burned 

 or otherwise carefully destroyed. On no account merely thrown aside. 



" When the trees are not growing in grass, and the ground beneath them is 

 free of crop, and also the Pear roots not too near the surface, the plan of skimming 

 the surface and destroying the surface earth with its contained infestation, would 

 answer well. 



"Where digging is admissible, this, if properly carried out, is serviceable ; but 

 if the operation only consists in breaking up the surface, as in the common method 

 of digging, it is not likely to do much good. The infested earth should (as noted) 

 be carefully buried away. 



" The best application to use for dressing appears, both from the published 

 experiments of Professor J. B. Smith, and also from our own trials to be kainite. 

 With regard to amount given in an experiment on infested Pear orchard land in 

 New Brunswick, United States of America, a heavy top-dressing of kainite was 

 applied in late summer, and under the infested trees it was applied at the rate 

 of over half a ton an acre. The result was that in the following year scarcely any 

 of the fruit was found to be infested ; while in another orchard close adjoining, 

 in which the ground had not been treated, on close examination it was found that 



