410 



Apfelbece (V.). Biologische Forsehungen uber Borkenkafer in den 

 bosnisehen Nadelholzforsten 1916. [Biological Investigations on 

 Bark Beetles in Coniferous Forests in Bosnia in 1916.] — Centralbl. 

 f. d. gesamte Forstwesen, Vienna, xlii, 1916, pp. 429-439. (Abstract 

 in Zeitschr. f. Pflanzenkrankheiten, Stuttgart, xxviii, no. 1-2, 

 1st February 1918, pp. 91-92.) 



In consequence of the War large stacks of timber have accumulated 

 in the coniferous forests in East Bosnia and provided breeding places 

 for bark -beetles. In many districts Ips typographus does not live on 

 spruce but on Pinus sylvestris. In the spruce woods broken branches, 

 tops, fence timber, and many ringed trunks provide shelter for 

 Pityogenes chalcographus and Pityophthorus micrographus. As a 

 general rule the primary pest in older spruce and firs is Pityogenes 

 chalcographus, which attacks the crowns of strong, healthy trees and 

 opens the way for infestation by Ips typographus. In poles Pityoph- 

 thorus micrographus or Polygraphus poly/^raphus effect this. In black 

 pine, Pityogenes pilidens, and in white pine, P. chalcographus and 

 P. quadridens, appear to prepare the way for other bark -beetles, 

 such as Ips mannsfeldi and /. sexdentatus. These branch- and top- 

 breeders also attack young growi}h. 



Natural enemies include parasitic Hymenoptera ; the Cucujid, 

 Laeniophloeus alternans, in the mines of I. vorontzowi ; the Tenebrionid, 

 Hypophlocus linearis, in the mines of P. chalcographus ; the Histerid, 

 Plegaderus imlneratus, in the mines of 7. curvidens and Crypturgus ; 

 and some Staphylinids. The paper concludes with a systematic list 

 of the bark-beetles infesting conifers. 



Parst ( — ). Die Fichtegespinstblattwespe {Lyda hypotrophica, Htg.) 

 im Roggenburger Forst. [Cephaleia abietis {Lyda hypotrophica) 

 in the Roggenburg Forest.] — Zeitschr. angewandt. Entomologie, iii, 

 1916, pp. 75-96, 4 figs. 



ScHEiDTER (F.). Beitrage zur Biologie und Anatomie der Fichten- 

 gespinstblattwespe, L. /i.,Htg. {= Cephaleia abietis, h.), [Contribu- 

 tions to the Biology and Anatomy of Cephaleia abietis, L.] — Idem, 

 pp. 97-116, 4 figs, (Abstracts in Zeitschr. f. Pflanzenkrankheiten, 

 Stuttgart, xxviii, no. 1-2, 1st February 1918, pp. 93-94.) 



The Roggenburg Forest in Swabia is at an altitude of 1,600 feet 

 and consists chiefly of spruce. In 1911 defoliated tops and branches 

 were noticed in 119-year-old trees. The injury began to diminish 

 at the time it was observed and no cause could be fomid mitil the 

 sawfly, Cephaleia abietis, was seen in large numbers. All stands, 

 including quite yoimg ones, were infested, but the old ones — especially 

 those of 80 years — were chiefly involved. The number of larvae 

 in the soil varied even under one and the same tree from 480 to 2,073 

 per square metre. The defoliation is not injurious, because only 

 the previous year's leaves are eaten, so that complete defoliation is 

 followed in the spring by green leaves. Feeding occurred in June 

 and July chiefly. In August the larvae migrate to the soil and remain 

 there till the second following spring (20-21 months). They do not 

 spin a web. Pupation takes place 10-14 days before the change to 

 the adult stage, but the preparations for pupation begin in the preceding 



