298 



to be present in great numbers, though the whole of the damage could 

 not be attributed to them, as they were always accompanied by 

 larvae of other species, such as Amphimallus solstitialis, L., etc. 

 A simple way of distinguishing between living larvae of Meloloniha 

 and those of AmpJimmllus, Phyllopertha, Anomala, Serica, Anisoplia, 

 etc.. is to place them on a hard smooth surface, when the former are 

 unable to get on their feet and remain lying on their sides, while all 

 the others can move away. 



As a result of the author's investigations, the Forestry Department 

 decided to establish several experimental forestries in the governments 

 of Vladimir, Tambov, Kiev, Kazan and others for the proper study 

 of this pest and its control. Some reports on the work done have 

 already been dealt with [see this Review, Ser. A, ii, p. 11 ; iii, p. 728 ; 

 iv, p. 101]. Although much still remains to be done and the work 

 of the experimental forestries has been hampered for various reasons, 

 the results accomplished are of much importance. The digging 

 operations are conducted on definite lines, the holes made being 

 combined into groups, numbered and entered on a map and in a book : 

 a great number of them have already been dug and they will in time 

 cover the whole of the forests and thus afford means of ascertaining 

 the number of larvae present in the soil and the foci of infestation. 

 While in the government of Lublin in Poland the larvae of M. hippo- 

 castani concentrate in open and drier spots, they tend to seek the 

 cover of the Avoods in some of the southern governments. Their 

 distribution also depends on the topographical features and the 

 character of the soil, the larvae preferring low-lymg ground. The 

 larvae of Polyphylla fuUo, L., on the contrary, prefer open and elevated 

 ground. As regards Melolonfha melolontha, it has been ascertained 

 that in those places where it is present together with M. hippocastani, 

 its larvae occur in fields and along the boundaries of forests, while 

 the larvae of the latter are found in the forests. All these larvae 

 readily eat the leaves of birch, oak and other trees, which fact may 

 be of practical importance in using poisoned baits and also shows 

 that living larvae may be transported in leaves as well as in soil. 

 It is also probable that, m cases of scarcity of roots, the larvae, 

 particularly in spring, when they are near the surface of the soil, feed 

 on leaves of Potentilla, Verhascum and similar plants, the leaves of 

 which grow close to the ground. For purposes of oviposition the 

 females avoid sandy or ploughed ground, which has no lumps or 

 similar objects against w^hich they can press their heads, when digging 

 themselves in. This points to reploughing and cultivation as a means 

 of control. 



Both M. melolontha and M. hippocastani have a four years' cycle 

 m the government of liublin, the flying years having been : 1895, 1899, 

 1903, 1907, 1911 and 1915, the next' one being expected in 1919; 

 in Tambov, Vladimir and Kazan, M. hippocastani has a five years' 

 cycle, 1917 being a flying year. Experiments have shown that larvae 

 of Melolontha can live in water for 18 days and the adults 12 days, 

 the larvae of A. solstitialis for 15 days, and those of P.fullofor 11 days, 

 indicating that flooding is useless. The enemies of cockchafers 

 observed included the predaceous lai-vae of Asilidae, which devour 

 both the eggs and young larvae, and the parasitic larvae of Tiphiu, 

 Scolia, Dexia and Minlho praeceps, the percentage of infestation by 



