264 



proved satisfactory for reasons as yet unexplained. Infestation was 

 slight, and the growth of the plants was rapid. A tobacco spray 

 containing 0-14 per cent, nicotine proved more poisonous than any 

 other spray tried, and further investigation is advisable, as nicotine 

 appears to act as a respiration poison on these beetles. Lime-sulphur 

 dust, naphthaline dust and turpentine gave good results on a small 

 scale, but need further testing. Soot, ashes, sawdust, horse dung 

 and road dust are efficacious on small plots if used in abundance. 

 Their value seems to lie in hindering feeding. 



Dr. Grosser describes an apparatus consisting of two inclined 

 boards, each twelve feet long and covered with an adhesive, mounted 

 on three wheels and drawn by a horse. Almost all the beetles caught 

 with this were M. aeneus, and while the infestation by this species 

 was originally very alarming, the crop ultimately proved a fair one. 

 Spraying with arsenicals, including Urania green, do not appear to be 

 of use against M. aeneus. 



MoRSTATT (H.). Bibliographie der Pflanzenschutzliteratur. DieJahre 



1914-1919. [A Bibhography of the Plant Protection Literature, 

 1914-1919.] — Biol. Reichsanst. Land- u. Forstwirtsch., Berlin, 

 1921, viii + 463 pp. [Received 13th March 1922.] 



Though issued at a later date, this volume precedes chrono- 

 logically the one for 1920 already noticed [R. A.E., A, ix, 445]. 



Mangin (M.). Une grande Invasion de Nonne : Lymantria monacha 

 dans les Forets de Tch^co-Slovaquie. — Bull. Soc. Path. Veg. 

 France, Paris, viii, no. 4, October-December 1921, pp. 140-144. 

 [Received 13th March 1922.1 



A serious infestation of the nun moth, Liparis [Lymantria) monacha, 

 was recently observed in Czecho-Slovakia. In Moravia, invasions of 

 this moth seem to be confined to certain foci, where energetic measures, 

 generally consisting of isolating ditches roimd the infested spots, 

 succeed in localising the outbreaks. Slovakia is at present apparently 

 immune, but in Bohemia the ravages of the moth are very serious, 

 certain heavy forest stands being almost entirely exterminated. 

 Both leafy and coniferous trees are attacked, though the former can 

 often put out fresh foliage, and are therefore less severely injured. 

 The depredations of L. monacha are aggravated wherever German 

 methods of forest culture are adopted, that is, pure stands thickly 

 planted and badly ventilated ; in the mixed leafy and coniferous 

 woods, carefully ventilated and regenerated in the French fashion, 

 the effects are much less deadly and do not entail wholesale felling. 

 The exceptional drought of 1921 undoubtedly aggravated the nun 

 moth attacks, especially in stands of Norwegian pine or larch. 



The trees that suffer most from L. monacha are pines and other 

 native conifers, birch, oak, beech, hornbeam, alder and apple. Limes 

 and pear trees have also been found infested. In badly infested places, 

 ash, elm and Pseudotsuga douglasi have remained immune. The 

 depredations of the nun moth began three years ago in Bohemia, 

 and seem to have reached their maximum in 1921 ; it is hoped that the 

 numbers will speedily be reduced by the infectious polyhedral and 

 flacherie diseases. 



The only measures that can be considered successful are all expensive. 

 They include the isolation of large areas by means of a trench around 

 the points of attack, and the application of tanglefoot on the trunks. 



