424 



piniperda was breeding, and in 10 per cent, it had tried in vain to ovi- 

 posit. This seemed to indicate that these trees had suffered to such 

 an extent from B. piniarius that they had become attractive to the 

 pine beetle. A closer investigation however showed that this was 

 not the case, only 1 of the 14 trees most seriously defoliated by 

 Bupalus piniarius having been attacked by the pine beetle, and 

 that in vain. Furthermore, one of the trees which in 1918 was attacked 

 by the pine beetle had during the two previous years escaped the attack 

 of Bupalus jnniarius. As a matter of fact the moth concentrates 

 on the largest trees, whereas the pine beetle prefers the smaller ones. 

 The results obtained during recent years in Sweden regarding 

 B. piniarius seem to make it clear that no precipitate measures, such as 

 cutting the timber, should be taken, as it often happens that the trees 

 do not succumb to the attack. 



Although there are four species of the genus Cephaleia, in Sweden 

 no records of any damage by these sawflies has previously been 

 recorded. In the summer 1916, however, at Dalby near Lund an attack 

 on spruce trees due to C. signata, ¥., was observed, the area in which the 

 injury occurred being 12^ acres, and the following year increasing to 

 about 185 acres. An investigation made in the autumn of 1917 showed 

 that 300-400 larvae were to be found in the ground. In 1917 the 

 swarming took place in the end of May. The eggs are deposited 

 singly on the old needles and are of a grey-green colour. The young 

 larvae emerged in the middle of June, but a large number of the eggs 

 (about one-third) were parasitised by a Chalcid, probably Entedon 

 ovulorum, a species reared by Ratzeburg from the egg of Lyda pratensis. 



Tragardh (I.). Barrtr&dskvalstret en Fiende i vara Plantskolor. 



[The Pine-tree Spinning Mite, Paratetranychus ununguis, Jac, 

 an Enemy in our Nurseries.] — Statens SkogsforsoksanstaU, Stock- 

 holm, Flygblad no. 14, 1919. 



Attention is called to the injury caused by this mite in nurseries. 

 The damage done as a rule passes unnoticed, the mite being too 

 small to be recognised as the cause. Near Vastervik, in Sweden, an 

 attack on 3-4 year old spruce trees was noticed in May 1918, which 

 would doubtless have caused the death of the plants unless the pest 

 had been detected and measures taken against it. The plants at this 

 time were of a red colour and covered with hibernating eggs. They 

 were sprayed with lime-sulphur, with the result that the mites were 

 killed and the plants saved. 



Friederichs (K.). Konnen schadliche Insekten durch parasitische 

 Pilze bekampft werden? [Can harmful Insects be combated by 

 Fungus Parasites ?] — Mitt. Naturf. Ges. in Bern, 1918, pp. xv-xvi, 

 (1919). 



After recording some of the more successful instances of attempts 

 to control insect pests by means of fungi, the author describes his 

 own experiments with Melarrhizium anisopliae in Samoa, where 

 the imported beetle, Oryctes rhinoceros, does tremendous damage to 

 coconut palms. Heaps of decomposing vegetation, treated with the 

 fungus, were placed so that the beetles should lay their eggs there, 

 with the result that all the larvae hatching out were destroyed. He 



