283 



scarce, and besides Icerya purchasi they attack Icenja seychellarum, 

 Mask., and Drosicha {Monophlebm) corpidenta, Kuw. Though the 

 CoccinelUd is rather active during the winter, in the field from 14 per 

 cent, to 22 per cent, of the larvae and from 33 per cent, to 67 per cent, 

 of the pupae, and in the breeding cages from 24 per cent, to 27 per cent, 

 larvae and 47 per cent, pupae, may die off. There are two fungi that 

 infest the larvae and kill them. 



In one area of 245 acres of infested orchard 670 CoccinelUd larvae 

 were liberated, and after two months the pest was nearly controlled. 

 As this Coccinellid is active from April to August, its introduction to 

 combat Icerya should be accomplished at this season. As it is 

 inactive in the A^anter, no effective result can then be expected from it. 

 It must also be remembered that the liberation of Novius cardutalis 

 even in large numbers cannot seriously check injurv' by Icerya purchasi 

 unless the conditions are suitable for the Coccinellids to breed and 

 increase. 



Icerya purchasi, Mask., has two or three generations a year, and is 

 mostly reproduced parthenogenetically. Though the newly hatched 

 larvae seem very active, they can travel only about 12 feet in an hour, 

 so that they cannot migrate to any appreciable extent unless aided 

 by birds or other insects. The dispersion of this scale must therefore 

 be chiefly caused by transportation of infested shoots or fruits. It 

 can withstand starvation to a considerable extent, and newly-hatched 

 larvae live 6 or 7 days, and adults 41 days on an average without food. 

 It is not only very injurious to the fruit by sucking the sap, but also 

 gives rise to a sooty mould on the foliage. Other natural enemies 

 that attack it are Noviu^ limbatus, Mots., and Chrysopa matsumurae, 

 Akamato, but they are less prolific and are of less practical value. 



ScHGYEN (T. H.). Om Skadeinsekter og Snyltesopp paa Skogstraerne i 

 1915. [Report on the Insect and Fungus Pests of Forest Trees 

 in Norwav in 1915.] — Saertryk av Skogdirektorens Irtberetniiig 

 for Kalenderaarel 1915, Chrisliania, 1917, pp. 154-159, 1 pi. 

 The larva of Dendrolimus pini was sent from Romsdals county, 

 and a full-grown larva of Lymantria monacha from near Christiania, 

 this being the third occasion that this moth has been found in Norway. 

 The author calls attention to the possibility of an outbreak of this 

 pest. Spruce cones attacked by Dioryctria (Phycis) abietella were 

 sent from near Christiania. Enarmonia {Grapholitha) nanaim and 

 Eucosma {G.) tedella, which were recorded as pests for the first time in 

 1913, were reported from north Trondhjem county. The larvae of 

 Cydia {Tortrix) coniferana and Dioryctria abietella were found in the 

 bark of pine trees on the sites of attack by the fungus, Da,syscypha 

 calycina. Myelophilus jiiniperda attacked pine trees that had pre- 

 viously been damaged bv sulphurous acid smoke from smelting works. 

 Anobium abietis was sent from Gjo\ak, where it was stated that for 

 some years the ground had been covered by cones attacked by this 

 insect. Lygaeonematus {Nemcitus) erichsoni was reported from one !^' 

 locality. Diprion [Lophyrus) pini was very numerous in the southern ]/ 

 part of the country, thousands of larvae being found on a single tree ; 

 young trees were preferably attacked. Chermes pini, which is the 

 most destructive pest of young pine trees in the western part of the 

 country, has been reported from several localities. Chermes abietis 



