COMMON COCKCHAFER. 207 



heaps of dung alternating with hiyers of earth, and enormous 

 numbers of hirvae may be reared in them and subsequently 

 destroyed. 



d. Traps of sticks or bark. In a swarm-year and the year 

 after it, at the beginning of the warm weather, fresh pieces of 

 bark or thin- barked, sappy branches 20 to 40 inches long are 

 placed horizontally, half covered with soil, in ground infested 

 with larvae. This may be done between the rows of plants in 

 nurseries, and aspen, sallow, ash, oak, and coniferous wood 

 can be used. These traps attract the larvae. This plan was 

 tried on a large scale in 150 forest ranges in Prussia in 1883 

 and 1884, but gave only poor results. In all the cases 

 (a to (/), the larvae must from time to time be collected and 

 destroyed, and the traps occasionally renewed. Oviposition 

 may be prevented by netting seed-beds, etc., in the spring. 



('. Trap-trenches one foot wide and one foot deep are 

 filled with moss. These are prepared in May and cleared 

 of larvae once a month up to late autumn, the moss being 

 replaced. 



/. "When a bed of seedlings or transplants has been seri- 

 ously injured, the remaining plants and all weeds should be 

 removed and fairly deep trenches dug round the bed. The 

 larvae in the beds will then be starved to death, or come 

 out into the trenches, when they should be killed. This is 

 practicable only with larvae not ready for pupation. 



V. Collection of the cockchafers in April and May is 

 probably the best remedial method to be followed. 



The chief points to be noted are : — The work should be 

 commenced early in the season before too many cockchafers 

 have emerged ; then only is it practicable to catch the $ before 

 they have laid their eggs. In order to ensure economy, 

 children and women should be employed, and the collection 

 made only in the morning or on cool days, when the insects 

 are sluggish in their movements. The workers are provided 

 with narrow-necked glazed vessels, or sacks in the opening of 

 which the broken neck of a beer bottle has been fastened, to 

 serve as a funnel through which the beetles may be dropped ; the 

 trees should be shaken over cloths, and payment should be by 

 quantity. Birch border trees round pine plantations, planted 



