1909.] Insect, Fungus, and other Pests. 925 



be the Hessian fly. Subsequently, owing to the doubtful 

 nature of the infestation, Mr. W. P. Jones, of the Loveston 

 Council School, Begelly, examined the infested land, and 

 forwarded specimens to the Board. The larvae (or pupae) 

 found we're said to be of a bright blood-red colour in August, 

 but when sent to the Board in November as pupae they were 

 rather lighter in colour. They were identified as the pupae 

 of one of the wheat midges (Diplosis aurantiaca), a species 

 which, like D. tritici, is a dangerous pest of wheat, while it 

 also attacks barley and rye. Notes on D. tritici and the 

 methods of combating it were given in this Journal in Sep- 

 tember 1907, p. 353, and October, 1907, p. 415, and these 

 may be taken to apply to D. aurantiaca. The pest would 

 not attack any crop other than a cereal or grass. 



Mealy Bug. — The term "Mealy Bug" is applied to two 

 members of the family Coccidce, viz., Dactylobius citri and 

 D. longispinus (formerly known as Coccus adonidum). 

 These two insects are harmful not only on vines but on other 

 greenhouse plants. The best treatment for destroying these 

 pests consists in fumigation with hydrocyanic acid gas (see 

 Leaflet No. 188). 



According to Newstead {Monograph of the British Coc- 

 cidce, Vol. II.), D, citri breeds rapidly in summer, and 

 although the males are not found in winter, all stages of the 

 female occur. This species secretes honey, and this is taken 

 as a food by ants. Where the insect is abundant the honey 

 collects on the leaves of the infested plants and acts as a 

 germinating medium for fungus spores. D. citri has been 

 recorded at Kew in the open, "on ivy-clad hothouse walls." 



D. longispinus resembles the former species in its mode 

 of life. It is a greenhouse species in temperate climates, but 

 an open-air species in tropical and sub-tropical countries. 



Mites in Flour. — A sample of flour from Norwich was 

 found to be infested by Aleurobius farincz, a mite which has 

 a widespread distribution, and may occur in abundance in 

 flour, dried grain, dried vegetable produce generally, and 

 also on cheese. Aleurobius lays its eggs in flour, in which 

 it breeds freely. The flour might be fumigated with bi- 

 sulphide of carbon in the manner described in Leaflets 136 

 and 150, and the flour would lose any taint on exposure to 



