Periodical Literature. 321 



In the year 1902 in certain provinces of 



Peculiarities Norway near the Swedish boundary the Pine 



of Moth (Lasiocampa pini L) suddenly ap- 



Pine Moth. peared in such great numbers as to be a 



serious pest, destroying considerable areas 



of pine forests, as reported by Mewes. 



Anticipating a spread of the pest across the boundary the Swed- 

 ish Department of Lands and Forests sent experts into Norwaj' to 

 familiarize themselves with the development of the insect and the 

 effective methods of combating it. At the same time colored charts 

 showing the insect in all stages of development and the n.iiiin 

 of the damage it does were distributed through such localiti-^s as 

 'were liable to attack. In two places the pest was found to con- 

 stitute a menace to the forest — one near the boundary and near 

 infested areas in Norway, and one isolated 30 miles distant. This 

 latter evidently stood in no relation to the area previously infested, 

 but had arisen independently. Search for pupae in the autumn of 

 1903 showed that this area was seriously threatened, while tlie 

 £rst mentioned required but little attention. 



About 290 ha. (755 acres) were involved, lying in a narrow strip 

 in the valley of the River Rottne. One-third of this area was cov- 

 ered with young growth (4-5 meters high), and observations in 

 Norway had indicated that stands of such age were not destroyed 

 the insects feeding here only early in the season, going later to 

 older trees, if such are to be found. 



During March and April, 1904, the large trees in tliis area were 

 painted with a narrow ring of birdlime. A. ring 2 cm. broad was 

 entirely sufficient, and not a single caterpillar was known to cross 

 and reach the crown. As anticipated, thickets and young polewood 

 stands were not seriously damaged, and the measures adopted were 

 thus effective in every respect. 



In Sweden the Pine Moth requires two years fov its development. 

 The parasitic Anomalon, living in its larva, however, keeps ihe life 

 period of one season normal to both insects in lower latitudes. Thus 

 it is clear why the Pine Moth so rarely does great damage in Sweden 

 and is so readily controlled. 



Der Kiefernspinner in Schweden, 190S und 1904. Zeitschrift 

 i'iir Forst und Jagdwesen. January, 1906. pp. 3.Q-43. 



