100 PEAK. [1899 



If the diseased little fruits can be shaken down, this saves much 

 trouble ; but in this case it is desirable that they should be shaken 

 down on to some material spread below, so that Pears and maggots 

 may be gathered up together, and thrown into a deep hole (where they 

 can be safely buried away) or on to a fire. A sticky material is the 

 best for shaking down on, as the maggots have good leaping powers, 

 and, unless prevented, may get away. 



Where 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. The depths given 

 for presence of the cocoons are half an inch to two inches, and this 

 might (I believe) often be safely removed. Any time would be suit- 

 able for this operation between the time of the falling of the infested 

 Pears from the trees, and such a date in the following winter or spring 

 as would ensure that the cocoons should be skimmed off and destroyed 

 in the hifested earth before the season came (or rather, drew nigh) for 

 the appearance of the Gnat Midges, which takes place with that of the 

 Pear blossoms. 



Where digging is admissible, this, if properly carried out, is ser- 

 viceable (see p. 98) ; 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 Prof. J. B. Smith (see note, p. 94), and also 

 from our own trials, to be hiinite. With regard to amount given in 

 an experiment on infested Pear orchard land in New Brunswick, 

 U.S.A., 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 per acre. The result was that in the following year scarcely any 

 of the fruit was found to be infested ; whilst in another orchard close 

 adjoining, in which the ground had not been treated, on close ex- 

 amination it was found that of one kind especially grown, fifty per 

 cent, were " midged," and of the other kind named not one could be 

 found to have escaped. 



But in the case of sprinkling with a small quantity of kainite, in 

 laboratory experiment, only three per cent, of living larviB were found 

 in the cocoons examined ; and where double quantity was used, " not 

 one-third of the larvffi in the jar had ever formed cocoons, and those 

 that did seemed all of them to be dead." 



Also, in laboratory experiment, Prof. Smith found that where 

 nitrate of soda was sprinkled in quantity that would represent a fair 

 top-dressing in ordinary held use, on sand in which maggots had gone 



