20 CORN AND GRASS. 



imagine, thus be congenial to most forms of insect life. I could not 

 assign any other reason for their occurrence, except that we are almost 

 surrounded by woods of Scotch Fir." 



This might very possibly be from the grubs feeding at the Fir roots. 

 In 1882, I had notes of much harm being done to young seedling Firs 

 by Cockchafer grubs removing the bark in large patches from the main 

 root, and in the previous year " thousands of the Fir plants " at the 

 locality had been destroyed. Another note was also sent me of very 

 bad injury, at Eardiston, m Worcestershire, to a young Pine p»lantation, 

 mostly Scotch Fir, from grubs of the common Cockchafer devouring 

 the roots close to the collar. 



In its perfect state, that is, as the Cockchafer Beetle, it does not 

 appear to frequent the leafage of Conifera3 ; it is noted in the ' Forst 

 Zoologie ' (Insecten), of Dr. Bernard Altum, that it will attack the 

 Larches " not unwillingly," but spares the other kinds, with the 

 exception of the male blossoms of the Pine, or Scotch Fir {" Kiefer"). 

 For the most part the Cockchafers attack the leafage of the common 

 forest trees, as Oak, Beech, Elm, &c., but, failing other food, they have 

 been known to supply their needs from " vegetables." This would 

 account for the grub having been reported to Mr. Wilson as present in 

 Orkney, which, he observes, is "innocent of trees." 



On asking Mr. England Wilson for the lowest temperatures, about 

 the time when the Cockchafer grubs were turned out alive on the 

 surface, he supplied me with the following readings. These were taken 

 at the Duuecht Observatory Station (about four miles distance), at 

 9 a.m., from a minimum thermometer in a Louvre box about four feet 

 above the ground, and were the lowest readings of the season : — 



1890, Nov. 28th, 18-9° ; Nov. 29th, 16-9°. 



1891, Jan. 8th, 13-8^; Mar. 9th, 17-0°. 



This of course does not give the precise temperature, either on the 

 surface of the ground or at five to six inches below it, where the cater- 

 pillar was turned up from, but shows that they could stand a cold of 

 approximately 18° of frost without being killed by it, so long as they 

 were left in their own shelters ; but when turned up to the surface, a 

 fortnight or so after, then they had not vitality enough to make new 

 shelters again in the ground. 



Later on in the season, I had Cockchafer grubs and a surface 

 caterpillar sent me from near Dorchester, by Mr. Arthur Edmondson, 

 as examples of an attack which was then, the 23rd of September, doing 

 mischief in a piece of white Turnips. 



Such means of prevention and remedy as can be brought to bear 

 have been previously entered on, but almost the only practicable plan 

 for clearing the grubs appears to be ploughing, so as to turn them out 



