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results and more or less failed even in the laboratory. The most 

 successful method and one which results in the catching of numbers of 

 queen ants is the use of traps made of bamboo stuffed with dried leaves 

 and laid about in the plantations under dead leaves and grass ; these 

 traps work well in the rainy season. In order to obtain the best results, 

 the dead leaves and other rubbish should be cleared away from under 

 the trees so as to deprive the ants of other shelter. Another plan 

 is to dig holes about 5 feet long by 2 feet wide and 8 inches deep at 

 short intervals between the trees in the plantations ; these are filled 

 with dry leaves and treated later with carbon bisulphide. 



ScHOEVERs (T. A. C). Een Nieuwe Havervijand {Tarsonemus spirifex, 

 Marchal), de Havermijt. [A new Oat Pest, Tarsonemus sjnrifex, 

 Marchal, the Oat Mite].- — Tijdschr. over Plantenziekten, Wageningen, 

 1915, pp. 111-123, 2 figs., 3 plates. 



In July, oats attacked by a species of Tarsonemus were received 

 from Almkerk. Both larvae and adults appeared to agree with 

 Tarsonemus spirifex, March. This identification was confirmed 

 by Dr. Oudemans. Some of the oat plants examined had a 

 very characteristic appearance. That part of the haulm which 

 forms the rachis of the panicle extended little beyond the leaf- 

 sheath, whilst the lowest branches of the panicle itself remained 

 altogether in the leaf-sheath. The rachis both within and without 

 the leaf-sheath, was twisted spirally like a corkscrew. This pest 

 has done great damage in some departments of France and the 

 attacked oats tillered very badly on poor dry soils. The one remaining 

 haulm is strongly violet-coloured and the panicle remains almost 

 entirely in the sheath and only the corkscrew-like stem, which forms 

 the principal axis of the rachis, emerges. On soils of better quality 

 some tillering takes place, and the violet colour of the upper haulms 

 is not so marked. Kirchner recorded this oat mite in Wurtemburg in 

 1903, and his description of the effects of the attack does not altogether 

 agree with that of Marchal, but this may possibly be explained by 

 the fact that the oats examined by Marchal were attacked in an 

 eatlier stage of growth, and that in Wurtemburg winter oats were 

 affected, whereas in France they were almost exclusively summer oats. 

 The author's observations agree rather with those of Marchal than 

 with those of Kirchner ; they were made at a later stage and the 

 grain was fully developed though not quite ripe. On the experimental 

 fields at Wageningen, which were seriously attacked, no examples 

 were found of the condition described by Marchal in which the panicles 

 remained in the sheath ; the twisting varied from a slight curve to a 

 complete spiral, and cases were found which suggested attack by 

 Tylenchus ; the violet colour was always on the leaf-sheath, never 

 on the haulm ; the spikelets were constantly attacked and mites 

 found within them, but in far smaller quantity than between the 

 leaf -sheath and the haulm. Tarsonemus spirifex has also been found 

 in Baden, Bavaria and Mecklenburg. The damage done is very 

 considerable and at Wageningen 90 per cent, of the haulms were more 

 or less attacked ; healthy plants were found exclusively on the borders 

 of the fields and they possibly escaped or survived attack by having 

 more room for growth. A field of " evene " next to the oats was 



