253 



Rebel (— ). Nonnenvermehrung im Hofoldinger Forst 1899-1902. 



[An Outbreak of the Nun Moth in the Hofoldmger Forest in 1899- 

 1902."' — Zeitschr. angew. Ent.. Berlin, \\i, no. 2, February 1921, 

 pp. 311-333. 



The details of the outbreak of the nun moth [Liparis monacha] 

 here described were officially reported at the time, but have not 

 hitherto been made public. 



The best method of ascertaining the extent of infestation is by 

 means of caterpillar counts. One method consists in banding a group 

 of trees (covering 120-240 square yards) in all older stands, and 

 collecting the caterpillars below the bands on each second day, their 

 number, the weather, and parasitism by Tachinids being noted. In 

 another method two similar! \^ banded plots, each of 120 square yards, 

 are isolated by sticky barriers (smeared poles laid on the ground), and 

 Ihe caterpillars on the ground and on the trunks beneath the bands 

 are collected daily. The living soil covering is removed and the trunks 

 numbered, the daily catches and the Tachinid parasitism being recorded. 

 This method is the more accurate, and is preferable in every way. 

 At the end of the season the trees were climbed and the caterpillars 

 still remaining on the branches collected. In the Hofoldinger forest 

 1 per cent, of the area was examined. This is quite unnecessary, and 

 in the case of fairly extensive areas of a uniform character the second 

 method only requires to be applied to ^joW of the area involved. 



JVIoth collection, even in the most favourable circumstances, only 

 accounts for 10-13 per cent, of the individuals capable of injury. 

 Heavy rain, especially when nocturnal, combined with a low 

 temperature, destroys large numbers of them. 



Great attention must be paid to natural enemies, and if they are 

 likely to be present in insufficient numbers, banding must be applied 

 in the very first year of the outbreak. 



A large number of apparently healthy caterpillars and pupae were 

 placed in extemporised cages. The result was surprising, for 88 per 

 cent, failed to develop. Qf these, 13 per cent, were shrivelled or 

 otherwise destroyed ; 5 per cent, were infested by Ichneumon disparts 

 and Tragus flavatorius ; 30 per cent, by the Tachinid, Parasetigena 

 segregata ; and 40 per cent, were infested by what was probably 

 Sarcophaga pahidans, Fall., which is a pupal parasite. Some larvae 

 of Anthomyia processioneae (?) were seen, and Pimpla spp. destro\'ed 

 some pupae. 



Sedlaczek ( — ). Fangbaummethoden fiir die verschiedenen Borken- 



• kaferarten. [Tree-traps suitable for the various Species of Bark- 

 beetles.] — Zeitschr. angew. Ent., Berlin, vii, no. 2, Februarv 

 1921, pp. 334-339. 



The subject of the attractiveness of withering timber to bark-beetles 

 still requires a great deal of study. This paper only aims at recording 

 characteristic observations as a guide to an}' measures contemplated 

 against the more important species. 



Lack of sap is due to a variety of causes, and soon shows itself in 

 a fallen tree. In such cases, and especially after a summer drought 

 or in a windbreak, the following bark-beetles, all of which like dry 

 surroundings, are to be found : Ips ( Tomicus) typograpkus and /. ( T.) 

 >chalcographtts in spruce ; /. ( T.) curvidens and /. ( T.) vorontzowi in 



