reports by the honorary scientists. 2o9 



Life-History. 



The female beetle burrows into the earth and lays little heaps 

 of eggs, from which, after four to six weeks, grubs hatch. May 

 and June are the months for the adult beetle. The grubs 

 hatching in the summer, feed during the summer and autumn of 

 the year of hatching, and continue their feeding in spring, summer, 

 and autumn of the two following years. Pupation then takes 

 place in the soil, but the beetles do not appear above ground till 

 the next May or June, i.e., a new brood of beetles may be expected 

 every fifth year, the generation lasting four years. In the cold 

 part of the year the grubs go deeper into the soil for protection. 



Preventive and Protective Measures. 



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

 exposed to the sun, that is, on land not covered by a tall 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 grubs into the nursery. 



(f ) 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, 

 both before and after planting, resulted, in the infestation mentioned 

 by Mr Fred Moon in his paper in another part of the Transactions, 

 in the discovery and destruction of 3000 grubs. 



Destructive Measures. 



{a) Collecting the beetles, taking care to begin with the earliest 

 of the year's flight. The beetles, which fly in the evening, collect 

 in the early morning and daytime on trees, from which they can 

 be shaken or beaten down, with long poles, on to cloths spread 

 below. The beetles are easily killed by dropping them into a 

 little paraffin or into boiling water. 



(b) When the grubs have got to work, they can be dug up by a 

 trowel or small spade. In addition to the symptoms of attack 

 previously mentioned, where withering of the parts above ground 

 has not yet revealed itself, badly infested plants will be found to 

 come away in the hand, with gentle pulling, and the grubs will 

 VOL, xviii. o 



