J. Kennie 



133 



Weather. 



From the beginning of October to the middle of March it was 

 exceptionally wet and boisterous. There was practically no frost 

 and the temperature was normally mild. The Farm is worked on 

 the five shift system; the present tenant came to the farm in 1910, 

 and previous to this the farm had been much neglected, especially as 

 regards drainage and weeds. Oats were sown in the last days of March. 

 After sowing, the field was immediately harrowed — one single and two 

 double. It was not rolled till 23rd May. 



The oats "brairded" in about a fortnight from sowing time and 

 looked strong and healthy for a week. About 20th April the crop- 

 began to look sickly in parts and by the end of another week the 

 presence and activities of Tipula larvae became apparent. The 

 weather for some weeks after sowing was warm and sunny. 



The state of the crop was reported to the College authorities in May, 

 and on 24th May arrangements were made to treat the field experi- 

 mentally. At this time, it showed parts fair, parts very thin, and 

 fairly large tracts were quite blank. All over the field leather jackets 

 could be readily found, and on the bare parts they were present in very 

 large numbers; scores could be found near the surface in a square 

 foot of soil. A part of the field including the worst portions was 

 plotted as under: 



The manures were applied on the 6th of June, and two-thirds of 

 the total area rolled early the following morning. On the 14th June 

 one half of that part was rolled a second time. The other third was 

 not rolled. 



On June 26th the larvae were still to be seen, and active. Ten 

 trial counts were made on square foot samples taken at random. These 

 were dug to a depth of six inches and the larvae counted. The follow- 

 ing are the numbers found : 4, 5, 4, 4, 5, 4, 12, 14, 14, 13. No sample 



Ann. Biol, m 9 



