161 



Wolff (M.). Ueber die Chalcidiergattung Chrysodmris, Forster 

 1856 (1861) (Hym.) und die erste aus Deutschland bekannt 

 gewordene Art Chr. kran.sse'L n. sp., sowie uber die Gattungen 

 der Derostenus-GiM^VQ Thomsons. [Notes on the Chalcid (Tienus 

 Chrysocharis, Forster, and the first Species known from Germany, 

 C. kraussei, sp. n., and on the Genera of the Derostemis Group 

 of Thomson.]~Entom. Miti., Berlin, v, no. 9-12, pp. 258-282, 

 9 figs., 1 plate. [Received r2th February 1920.] 



In 1915 a number of Chalcid pupae were received on a plane leaf, 

 grouped round a spot where their host, probably some Lepidopterous 

 larva, had died. The adults proved to be a new species here described 

 as Chrysocharis kraussei. In view of the lack of information available 

 on the genus Chrysocharis, Forster, this paper gives a key to the 

 various species and also to the genera of the Derostemus group. 



EosENFELD (W.). Schlupwespon und Borkenkafer. [Hymenopterous 

 Parasites and Bark-beetles.] — Entom. Mitt., Berlin, viii, no. 1-3, 

 8th February 1919, pp. 29-37, 9 figs. [Received 12th February 

 1920]. 



Very little information exists regarding the occurrence of 

 Hymenopterous parasites of bark -beetles. In 1916 damage by snow 

 anl wind to the forests in Austrian Silesia was followed by an 

 abun lance of bark-beetles that provided an opportunity for 

 studying their enemies. 



Most of the parasites observed in 1917 and 1918 were Chalcididae, 

 the majority belonging to the subfamily Pteromalinae. The 

 larger beetles, such as Ips typographus. L., and I. amitinus, Eich., 

 were attacked by the larger species, while the smaller ones, such as 

 I. chalcographus, were infested by the smaller parasites. The following 

 were identified : Braconids, Cosmophorus Jdugi, Ratz. ; Chalcidids, 

 Rhopalicus suspensus, Ratz., R. deniulus, Ratz., Rhophocerus eccopto- 

 gastri, Ratz. The presence of Hymenopterous parasites is betrayed 

 by their pupae in the mines of the beetles. From the end of April 

 to the beginning of May the adults emerge by cutting a hole in the 

 bark. Mating immediately follows and the females deposit their 

 eggs close to the beetle laivae or pupae beneath the bark. The beetle- 

 infested stumps in sunny, sheltered places in damaged spruce woods 

 are preferred for oviposition. On hatching the parasitic larvae attack 

 the adjacent larvae of the host which gradually decrease in size. 

 This process lasts 2 or 3 weeks and the parasitic larvae then pupate. 

 A larva that had finished feeding on 14th June 1918 pupated on 20th 

 June and the adult emerged on 7th July. In captivity the entire 

 life-cycle from oviposition to emergence lasted 38-45 clays. There 

 are therefore several annual generations. The number of parasites 

 is considerable. Two spruce stems, each 16 inches long by 5 inches 

 thick and strongly infested with /. typographns and /. amitinus, 

 yielded 80 Chalcidids from 20th August to 11th September. 



The conclusions reached are that an outbreak of bark-beetles is 

 always accompanied by a large increase of Hymenopterous parasites. 

 Dry weather not only favours the parasites but restricts the number 

 of breeding-places of the beetles by causing the desiccation of a 

 number of sites that otherwise would be used. The Hymenoptera 



