454 Forestry Quarterly. 



pounds of chicle gum when from 8 to 10 years old and from 12 

 to 15 inches in diameter. In its wild state the tree is usually 

 found in groups, frequently growing to a height of from 40 to 50 

 feet; it is straight, and has a long, clear length, thus making it 

 most desirable for timber. While it grows well in a variety of 

 soils it seems to thrive best in a rich clay loam, with good drain- 

 age and an annual rainfall of about 90 inches. 



Chicle, the Basis of Chewing Gum. Bulletin of the International Union 

 of the American Republics. October, 19x19. 



The "Nun" (Lymantria monacha, L.) , a 

 Combatting close relative of the gypsy moth, is one of 



Insects. the most destructive insect pests in Europe, 



returning periodically. As a result of long 

 extended observations and investigations in library and field Dr. 

 Sedlaczek of the Austrian Experiment Station publishes a very 

 exhaustive article, the conclusions of which are of interest as ex- 

 hibiting biological habits that may apply more or less generally 

 to the family of spinners. 



As regards the origin of an invasion this appears to be autoch- 

 thonous. 



Eggs are deposited at varying heights according to site, 

 weather during the flight and other exterior influences, and in 

 the same stand can in different years be at different heights. 



Neither when young, nor in later life, do all caterpillars leave 

 the once chosen location. According to species, site and other in- 

 determinable influences sometimes a larger, sometimes a smaller 

 number descends. Pupation takes place at varying heights. Du- 

 ration and liveliness of flight depends on weather. The moths, 

 like the caterpillars come down out of the crowns only when 

 exterior influences force them. 



To be eaten clean, requires a predisposition of the stand. 



Precautionary revision consists in gathering moths by day in 

 not too high and too dense stands. Baiting by means of torches 

 is successful only in dark, warm, calm nights. Egg masses should 

 be determined carefully on felled trees, and not only the number 

 but the position in height should be noted. Providing means of 

 gathering excreta is commendable. Trial baiting with insect 

 lime is uncertain in results and lack of success does not assure 

 the absence of the pest. 



