476 



As unusiud dryness is one of the predisposing causes of this con- 

 dition, one of the simplest remedial measures is to keep the plants 

 well watered and work the soil around them so as to make it very 

 permeable. Insecticide sprays, or even water, directed upwards, or 

 sulphur powder applied with pressure, will kill the mites, but the 

 plants should always be kept well watered also. Lime-sulphur solu- 

 tion in 5 per cent, strength has proved very successful in penetrating 

 the webs. Some degree of control is maintained by natural enemies, 

 but predators have the disadvantage of destroying simultaneously 

 both the mites and any parasites hving upon them. The Coccinelhd, 

 Rhizohius litura, F., which devours Tetranychus spp. in all stages, has 

 been reared in small numbers in Mentone, as have PuUiis sp. and 

 Scymnus sp. Minute Staphylinids, probably of the genus Hypocyptus, 

 seem to accompany the colonies of mites, probably living on their 

 secretions. 



HiTiER (H.). Un Parasite du Puceron lanigere. [A Parasite of 

 Eriosoma lani^cnim.] — //. Agric. Prat., Paris, xxxvi, no. 30, 

 30th July 1921^ p. 101. 



Attention has been directed for some time towards the possibility 

 of finding a parasite of Eriosoma lanigerum, which is so destructive 

 to apple trees in France. The Chalcid, Aplielinus mali, has been intro- 

 duced in small numbers from America, and has been very carefully 

 propagated in special cages at various entomological stations. The 

 results up to the present have been encouraging. Too much must not 

 be expected, however, as the multiplication of the parasite in spring 

 is slower than that of E. lanigerum ; later in the season its activities 

 may be of great benefit. 



WoLDA (&.). Vogelkultuur en Vogelstudie. [The Encouragement 

 and Study of Birds.] — Verslag. & Medcd. Phytopath. Dienst, 

 Wageningen, no. 17, January 1921, 28 pp., 7 figs., 1 plate, 1 table. 

 [Received 3rd August 1921.] 



In 1920 an ornithological section was included in the Dutch Plant 

 Protection Service. The encouragement of birds is very desirable, 

 especially in view of the continued infestation by the nun moth [Liparis 

 monacha] and the outbreaks of the pine moth, Panolis fiammea 

 {piniperda), in recent years [R.A.E., A, viii, 225]. 



Bestrijding van Plantenziekten in kleine Tuinen. I. [Measures 

 against Pests of Plants in small Gardens.] — Verslag. & Meded. 

 Plantenziektenk. Dienst, Wageningen, no. 19, Februar}- 1921, 20 pp., 

 3 plates. [Received 3rd August 1921.] 



Recpiests for information regarding remedies against the more im- 

 portant insect pests and fungous diseases of plants in small gardens in 

 Holland has led to the issue of a simple manual of which this 

 bulletin, dealing with winter measures, is the first part. It is essentially 

 popular in character. 



