581 



but had not apparently reached the roots. By this date many winged 

 individuals were to be seen on the apple foliage, but none on the 

 elms in close proximity to the nursery, though there was evidence 

 of heavy infestation on these early in the season. By 27th May the 

 winged individuals had disappeared from the grafts and seedlings, 

 and several colonies were found below the surface of the soil in wounds, 

 leaf scars, etc. By 16th June the aerial colonies decreased ; some of 

 the Aphids were still migrating to the roots, but in smaller numbers 

 than previously. Of 50 seedlings examined, 25 contained colonies on 

 the roots, whereas only 12 of the grafts were found to be infested. 



Timely applications of nicotine and soap destroy the newly estab- 

 lished aerial colonies and greatly retard root infestation. In the 

 experiments here described a spray containing 40 per cent, nicotine 

 sulphate diluted 1 to 400 and resin fish-oil soap at the rate of 8 lb. 

 to 50 U.S. gals, was applied with a three-gallon compressed air sprayer. 

 On the 27th May the trees were sprayed thoroughly from one side, 

 the treatment being repeated after 20 minutes from the other side of 

 the rows. A second application was made on 9th June. 



Owing to the injury caused to the roots, potassium cyanide and 

 calcium cyanamide cannot be recommended for the destruction of the 

 Aphids infesting this portion of the plants. Liquid creosote used at 

 the rate of 1 part to 30 parts of water and applied to the trees at the 

 rate of 1 U.S. quart per tree did not show appreciable injurj^ to the 

 roots but effectually destroyed the Aphids. There are many difficulties 

 in treating the roots with liquid insecticides, but further trials with 

 creosote should be undertaken. 



Rutgers (A. A. L.). Verslag [Report] van den Directeur 1 Juli 1921- 

 30 Juni 1922.— Meded. Algein. Proefst. A. V.R.O.S., Medan, 

 Algem. Ser., no 14, 1922, 27 pp. 



In the entomologdcal section of this report Dr. C. Heusser records 

 that most of the Hevea seed-beds were infested by mites. Oil palms 

 suffered from an increased attack by Oryctes rhinoceros, L.] and Rhyn- 

 chopJwriis ferrugineus, Oliv.]. Phytonis dUatatns, Jac, did considerable 

 injury' to tea in some localities. Injur\^ to tea by HelopeUis was 

 successfully kept down b^' systematic collection. The red coffee borer, 

 Zeuzera coffeae, Nietn., occurred on one estate. As regards the coffee 

 berry borer [Stephanoderes hampei, Ferr.], estates that adopted such 

 radical measures as " rampassen " [R.A.E., A, x, 506] obtained excellent 

 results, the percentage of infested red berries falling from 40-90 per 

 cent, to 0-5-3 per cent. An experimental plot of Hibiscus cannahinns 

 was markedly injured by a beetle, Agrilus acutus, Thunb. 



Zetek (J.). La Enfermedad " Circulo rojo" de las Palmas de Coco. 



[The Red Ring Disease of Coconut Palms.' — Rev. La Salle, 

 Panama, \d, April 1922, pp. 463-466, 1 fig' [Received 25th 

 September 1922.] 



The red ring disease of coconuts is widespread throughout the 

 Republic of Panama. According to NoweU it is due to a Nematode, 

 Aphelenchns cocophilus, Cobb [R.A.E., A, viii, 411]. It is probable 

 that this pest is introduced into coconut plantations by means of 

 infested nuts. Its increase is also favoured by the fact that felled 

 palms are allowed to lie and become a focus of infestation. The 

 Nematodes are also carried from one palm to another by various 



