233 



RiTZEMA Bos (J.). Ziekten en beschadigingen, veroorzaakt door dieren. 



[Diseases and Damage caused by Animals.] — Meded. R. Hoogere 

 L(md-, Tuin- en Boschbouivschool, Wageningen, xi, no. 5, 1917, 

 pp. 169-250, 



This paper is a section of the report of the Instituut voor Phyto- 

 pathologie, Wageningen, for the year 1914, portions of which have 

 already been published [see this Review, Ser. A, iii, 194, 195, 644]. 



Nematodes. Tylerichus devastatrix, Kiihn, injured rye, Hyncintkus 

 candicans and H. orientalis, and was probably the species responsible 

 for damage to strawberry plants. Aphelenchus fragariae, Ritz. Bos, 

 and A. onmrodis, Ritz. Bos, were received on strawberry plants. 

 Chrv^santhemum leaves were attacked by A. ritzema-hosi, Schwarz. 

 Heterodera schachtii, Schmidt, occurred on beet and oats, while 

 H. radicicola, Greef, was found in roses, Delphinium and cucumber. 

 Plectus parietinus. Bast., occurred in strawberry plants. 



Thysanoptera. Against Liothrips sethwdis, Reut., on Lilium 

 pardalinum, dipping the bulbs for 15 minutes in a solution of 2 per 

 cent, of soft soap and 1 per cent, methylated spirit proved ineffectual ; 

 with carbon bisulphide, 500 c.c. per 40 cubic feet, the insects became 

 stupefied, but most of them revived, even after fumigation for four 

 hours. Fumigation vnih benzine gave b^ter results. The possibility 

 of attacks on cereals by thrips, especially Limothrips cerealium, Hal., 

 being influenced by the date of sowing was tested by sowing three lots 

 of oats on 31st March, 10th April, and 22nd April respectively. When 

 harvested in August, these lots showed great differences, the first being 

 almost uninjured, the second only slightly so, while the third was 

 considerably damaged. Such experiments should be repeated for 

 several years in order to obtain conclusive data. 



Lepidoptera. From cocoons collected from band-traps on apple trees 

 Swammerdammia pijrella, de Vill., was bred. Defoliation of a pear 

 tree was caused by the larvae from eggs laid by the first generation 

 of Leucoptera {Cemiostoma) sciteUa, Z. (pear-leaf blister moth). Phyl- 

 hnjcter {LitJiocolletis) concomiteUa, Bankes, infested apple trees. 

 This leaf-miner can be reduced in numbers by picking and burning 

 infested leaves and removing fallen ones. Greenhouse roses were 

 attacked by a leaf-rolling caterpillar, either Eucosma {Spilonota) 

 roborana, Tr., or E. {S.) rosaecolana, Dbl. An attempt was made 

 to control this pest by capturing the moths and by burning the infested 

 buds. Fruit trees, especially cherries, were attacked by Chebnatobia 

 brumata. Many eggs are deposited on the trunks between the ground 

 and the sticky banding, and as even the best samples of the latter 

 lose their efficiency by March, many of the caterpillars are able to 

 reach the crown of the tree. A 10 per cent, solution of carbolineum, 

 which may safely be used on the trunk, will kill such eggs and also the 

 hibernating pupae of Cydia pomonella and Porthesia similis, Fuessl. 

 For experimental purposes some cherry trees were banded, while 

 others, left unhanded, were sprayed in the second half of February 

 vnih a 7| per cent, solution of carboHneum. None of these were 

 attacked by C. brumata, whereas untreated control trees were injured. 

 This shows that, when banding has not been apphed or where its use is 

 impossible, as in the case of bushes, one spraying with carbolineum 

 provides a sufficient control. The constant occurrence of Chloroclystis 

 (C370) Wt.P5/131. 1,500; 6.17. B.&F.Ltd. G.11/3. A 



