60 



indigenous plant, Barringfonia racemosa, was neither this species nor 

 A. transparent. 



A leaf-miner heavily infested mustard leaves, on which numerous 

 small black flies were seen. 



Pax (F.). Beobachtungen iiber Beschadigungen von Bleikammern 

 durch Holzwespen. [Observations on Damage to Lead Chambers 

 by Wood Wasps.] — JahresJi. Ver. schles. Insektenk., Breslaii, 

 xiii, 16th December 1921, pp. 43-56, 1 plate. 

 The floors of the lead chambers in a new sulphuric acid factory, 

 built at a cost of 3^ million marks early in 1921, near Saarau, Silesia, 

 proved leaky when tested with water, owing to the presence of small, 

 circular holes, and examination in July and August showed that all 

 the constructional timber was infested with wood-wasps. In one 

 instance no less than 15 holes were found in 32 inches of a wooden 

 pillar. Timbers that were split open revealed many larval mines, 

 pupae and adults. Some of the perforations in the lead floor-plates 

 led back to the underlying wood flooring, and some dead wasps were 

 found half in the wood and half in the lead. Only the floor-plates, 

 which were in contact with the wood flooring, were perforated. The 

 lead sides were separated from the wood casing, so that in this case 

 the insects could emerge without working through the lead. Sirex 

 gigas, L., was the species principally concerned, but 5. [Paiiritriis) 

 juvencus, L., and S. (P.) nodilio, F., were also present. It is probable 

 that all three are equally injurious. 



Replacement of the infested timber was not feasible on account 

 of the enormous cost, nor was it possible to wait until all the adults 

 had emerged before repairing the lead chambers. The infestation 

 may possibly last until the end of September 1923. Fumigation with 

 hydrocyanic acid gas, or the employment of heat to destroy the insects, 

 is not practicable owing to the size of the buildings. Oviposition 

 may be prevented by painting with carbolineum, but existing infesta- 

 tion would not be eUminated thereby, and boring sometimes occurs 

 through an impregnated layer. The only feasible measure was a 

 protective metal sheet between the lead and the wood. An inter- 

 mediate layer of iron plates was therefore placed in position, at a 

 cost of 100,000 marks, after which the trouble ceased ; but for 

 technical reasons it may be necessary to remove this later on. 



As it is believed that Siricidae usually oviposit in unhealthy or 

 freshly-felled coniferous timber, care must be taken in selecting the 

 wood for sulphuric acid factories. This was not done in the case in 

 question, for the timber showed traces of infestation by other insects 

 as well, including Pissodes piceae, Trypodendron lineatum, and a species 

 of Hylastes, perhaps H. angiistatus. 



Infestation of freshly-felled timber by wood-wasps may be pre- 

 vented by painting with carbolineum or creosote, or such woods as 

 are not attacked by Siricids should be used for the flooring of lead 

 chambers. 



Ferdinandsen (C.) & RosTRUP (S.). Oversigt over Sygdomme hos 

 Landbrugets og Havebrugets Kulturplanter i 1920. [Report on 

 Insect Pests and Fungous Diseases of the Field and Orchard 

 in 1920.] — Tidsskrift for Planteavl, Copenhagen, xxvii, 1921, 

 pp. 697-759. 

 The cereal pests recorded are: — Contarinia tritici and Sitodiplosis 



mosellana (C. anrantiaca), which severely attacked wheat and barley, 



