466 



Fields that have been left uncultivated for a time sometimes produce 

 well when first planted again. This may be due to the wild flowers 

 in the uncultivated fields attracting the parasitic wasps {Canipsomeris 

 and Scolia), which normally must go far from the cane area in search 

 of nectar-bearing flowers, few probably returning. The planting of 

 nectar-producing shrubs is therefore recommended. A satisfactory 

 method of using arsenic for cane-grub control has yet to be discovered ; 

 placed in furrows on either side of the stools, it has proved useless. 

 The destruction of feeding trees, which has recently been tried [R.A.E., 

 A, vii, 110], seems likely to prove beneficial. 



In the Babinda area, which is a very humid one, white grvibs have 

 not appeared, but a weevil, Rhabdocnemds ohscura, is a serious pest 

 and is spreading rapidly. A more extensive effort to introduce colonies 

 of its Tachinid parasite [Ceromasia sphenophori] is being made. 



Jarvis (E.). Doticus sp. (D. pestilem) attacking Granadillas in Queens- 

 land. — Queensland Agric. Jl., Brisbane, xiv, no. 1, July 1920, 

 pjD. 36-37. 



A Coleopterous larva, probably Doticus pestilens, was found in a 

 hole in green granadilla fruit, and when transferred to a sound fruit 

 burrowed into it [c/. R.A.E., A, ii, 511], and successfully completed its 

 development. 



Hirst (S.). Revision of the English Species of Red Spider (Genera 



Tetranyclius and Oligonychus.) — Proc. Zool. Soc. Londo'n, 1920, 

 part 1-2, July 1920, pp. 49-60, 5 figs. 



The distinguishing characters of the genera Tetranychus and OH- 

 gonychus are described, and a key to the species of Tetranychus occurring 

 in England is given. The species dealt with include Tetranychus 

 crataegi, sp. n., described from hawthorn hedges in Wiltshire, and 

 T. ialisiae, sp. n., from a South American tree {Talisia princeps) in 

 Kew Gardens. 



MoLZ (E.). Die Typhula-Fsmle der ZuclterrUben auf den Azoren und 

 ihre Bekampfung. [Typhula Rot of Sugar-Beet in the Azores 

 and its Control.] — Zeitschr. Pflanzenkr. Stuttgart, xxx, no. 4-5, 

 1920, pp. 121-139, 7 figs. 



In the Azores the spread of Typhula and its capacity for infecting 

 sugar-beet are much aided in dry soils by injuries to the plant by the 

 caterpillars of Euxoa [Agrotis) segetum, the wounds made by which 

 readily give access to infection by this fungus. The immunity of 

 young sugar-beets to infection by Typhula is due both to their lesser 

 sugar-content and to the absence or comparative absence of the 

 caterpillars at that time. 



ZiMMERMANN (H.). Nematodcnbefall (Heterodera) an Kartoffeln. 



[Nematode (Heterodera) Infestation of Potatoes.] — Zeitschr. 

 Pflanzenkr, Stuttgart, xxx, no. 4-5, 1920, pp. 139-145, 4 figs. 



In 1913 potatoes in Mecklenburg were found to be attacked by a 

 species of Heterodera, as yet undetermined, the spread of which was 



