1904.] 



The Cockchafer and Forestry. 



559 



Larva, — The grubs are thick, fleshy, and dirty white, the tail 

 end of the body being swollen and darker in colour ; the head 

 is shining brown, the mouth being provided with strong 

 mandibles ; the legs are paler brown ; the joints of the body 

 are wrinkled and covered on the upper surface with bristles. 

 In the soil the grub lies curled on one side. 



Pupa. — The pupa is naked, lying in the soil. 



Lije History. 



The female beetle burrows into the earth and lays her yellow- 

 white eggs, some seventy in all, in little heaps of twelve to thirty, 

 and after four to six weeks the grubs hatch out. The adult 

 beetles are found in May and June. The grubs hatched, say, in 

 June and July of 1904, feed in the summer and autumn of this 

 year, and then during the late spring, summer and autumn of 

 the next two years, completing their feeding in June or July 

 of 1907, when pupation will take place in the soil. The period 

 of pupation is comparatively short, so that the beetles are ready- 

 by October or November, 1907, but they will not come above 

 ground until May or June of 1908. In the cold months of the 

 year the grubs cease feeding, and go deeper into the soil for 

 protection. While in our country a new generation of beetles 

 may be expected every four years, the development is shorter 

 by a year in warmer countries, and longer by a year in colder. 



Preventive and Protective Pleasures. 



{a) The beetles lay most willingly on light soil and on 

 places exposed to the sun, that is, on land not covered by a tali 

 crop ; it is therefore advisable to avoid a " clear cutting " on a 

 large area in a swarm year, or in the year before swarming. 



{b) Grass land is often infested with the grubs ; plantings 

 therefore of young conifers adjoining such should be separated 

 from the grass land by a narrow trench to prevent the passage 

 of the grubs into the nursery. 



(c) Ball planting with vigorous plants. 



(d) Collecting the grubs during the preparation and working 

 of the soil. The diligent collection of grubs on quite a small 

 area before and after planting resulted in a recent case in the 

 discovery and destruction of 3,000 grubs. 



