68 PEAK. [1000 



shaking and jarring thoroughly, many of the infested fruits, with their 

 maggot contents, will fall, and can be gathered together and burnt ; 

 but in all likelihood some may have previously fallen (or the maggots 

 out of them), and some may still remain on the trees. To meet this 

 difficulty no plan seems likely to answer (so far as shaking down is 

 concerned) excepting carrying this out from time to time : or more 

 especially keeping cloths smeared with grease or with tar in moist state 

 under the trees, which the maggots as they fell from above, or came 

 out from the fallen pears, would adhere to, and thus further mischief 

 be checked. 



Where, however, ijronnd beneath the trees is bare, probably all trouble 

 of gathering or shaking down might be saved by skimmimj off the 

 surface containing the maggots, or the cocoons in which they turn to 

 chrysalids, which lie from half an inch to two inches below the surface. 

 Small though they are, the maggots and also the silky cocoons are 

 large enough (see figure, p. 63) to be distinguished with the help of a 

 magnifier, especially by one of the orchard superintendents interested ; 

 and if removed and burnt in the skimmed-off soil any time before the 

 beginning of the following spring, when the Gnat Midges will come 

 out at the time of the appearance of the Pear blossom-buds, there 

 does not seem to be any reason for doubting that the plan would 

 act well. 



Where orchards are on yrass-iand the only treatment, excepting 

 shaking down or hand-picking to get rid of the maggots, appears to be 

 poisoning them or preventing their development to chrysalid condition 

 by the application of chemical dressings ; choosing, of course, such as 

 are also beneficial as stimulants to plant growth. 



Details of the different kinds of dressings found serviceable, and 

 amounts used, have been given in my two preceding Annual Keports ; 

 but usuaUy the best application to use for dressing appears, both from 

 the published experiments of Prof. J. B. Smith (see note *) 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, 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 examination 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. 



Nitrate of soda was also found, in the same series of experiments, 



* For valuable observations on this attack, see ' The Pear Midge {Diplom 

 pyrivora, Riley)." Bulletin 99 of New Jersey Agricultural College Experiment 

 Station, April 4th, 1894. 



