610 PEOCEEDL^GS OF THE THIRD ENTOMOLOGICAL MEETING 



25.—TUKRA DISEASE OF MULBERRY. 



(Plate 98). 

 By C. S. MiSRA, B.A., First Assistant to the Imperial Entomologist. 



(1) Dadylopius hromelice, Bouclie., Naturgesiclit, 1834, p. 20. 



(2) D. hromelice, Signoret, Annales de la Soc. Ent. de France, De 



cember, 1874, p. 310. 



(3) D. bromeliw, Ind. Mus. Notes, Vol. Ill, No. 5, p. 51, fig. 52. 



(4) D. hromelice, Boiiche ; C. S. Misra — The Tulcra Disease of Mul- 



berry. A Report on the Silk Industry in India by H. 

 Maxwell- Lefroy (1915). 



(5) Pkenacoccus Tiirsutus, Green. Mem. Dept. Agric. Ind.. Entl. 



Series, Vol. II, No. 2, April 1908, p. 25, Plate II, fig. 1. 



The disease locally known as " Tukra " in Bengal is caused by Pkena- 

 coccus hirsidus. Green. Hitherto it was thought that the cause of the 

 disease was Dactylopius hromelice, Bouche. But early in July last year ' 

 (1918) specimens were sent to Mr. E. E. Green and he has now identified 

 the Mealy-tugs causing the Tukra disease as Pkenacoccus kirsutus. Green. 

 The disease was noticed for the first time by me at Pusa early in 1908, 

 but with the pressure of other work further investigations regarding 

 the cause of the disease could not be taken up. In April 1909, when I 

 visited the Babulbona nurseries in the Murshidabad district, my atten- 

 tion was drawn to the damage done to the bush mulberry plantations 

 in the nursery compound. The mealy-bug was so bad that hardly a 

 plant was free from it in the nursery plantations, and Mr. A. C. Ghosh, 

 Superintendent of the Babulbona nurseries informed me that the disease 

 was very widespread in the interior of the district, and m cousecjuence 

 I visited some of the villages in the neighbourhood of Murshidabad and 

 found the disease very bad in a large number of bush mulberry fields. 

 In some places the disease was so bad that there were hardly any green 

 succulent leaves on the plants. All that was present on them were the 

 hard, compact, malformed shoots in which the leaves had turned dis- 

 • tinctly coppery-green or pale-yellow. The apical leaves forming the 

 malformed heads had become so crisp that it was hardly possible to 

 examine them without breaking them. Later on, a large number of 

 stiay bush mulberry plants — the remnants of a former roadside planta- 

 tion at Pusa— were found to be severely affected with the disease and 

 on examination were found to be infested with the nymphs and adults 

 of P. kirsutus, Gr., in every stage of development. These plants were 

 kept under observation until, early in 1916. specimens were obtained 



