1907.] Insect, Fungus and other Pests. 



479 



In combating this insect the vulnerable stage is the resting 

 stage, when the grubs are in the stubble after the crop has been 

 harvested. Where attack has been bad the stubble should, 

 if practicable, be burnt over, or removed and burnt, with the 

 result that the full grown grubs are destroyed. Burying the 

 stubble would only be efficient if it were turned in deep enough 

 to prevent the sawflies on development from reaching the 

 surface. 



Other sawflies submitted to the Board included specimens of 

 apples from Swanage infested by the apple sawfly, an account 

 of which appears on p. 482 of this Journal; and larvae of 

 the pear sawfly from Wallingford, where they were infesting 

 damson and cherry trees. This pest is dealt with in Leaflet 

 No. 62. 



Mites. — Specimens of begonias from Bath were found to be 

 infested with the Begonia mite, Tarsonymus. This mite 

 does not confine its attack to begonias, some species of which 

 seem to be more susceptible than others, but also infests 

 a number of other plants. The mite was determined by 

 Mr. Michael and reported in the Gardeners' Chronicle for 

 1 6th November, 1895. Closely allied species have on occasion 

 done much harm to box and to. sugar cane. 



With begonias the pest seems to be held in check if the plants 

 are dusted with tobacco powder. Tobacco water and fumigat- 

 ing with tobacco are also favourably mentioned. Against the 

 pest on sugar cane Mr. Michael recommended powdered 

 sulphur in soap and water to be applied at intervals, because 

 eggs may escape the first treatment. Sulphur is a well-known 

 treatment for mites generally, the treatment recommended for 

 the black currant mite being to dust the plants with a mixture of 

 two parts of sulphur to one part of finely ground unslaked lime. 

 The begonia mite spreads very rapidly where the cultural 

 conditions favour it, and the increase is especially marked 

 when the plants are allowed to become too dry. A case is 

 known in which the mite, at one time a great pest, is now 

 easily kept in check by the thorough and repeated syringing 

 of the plants with clean water. 



Specimens of black currants infested with the black currant 

 mite (Leaflet No. 1) were received from Worcester. 



Among other pests found attacking specimens submitted 



