66 



only the top layers are infested, it is obvious that a receptacle that is 

 large and wide at the bottom and very narrow at the top is advanta- 

 geous. The natives do, in fact, use such a receptacle, made of plaited 

 straw, the seed being taken out of a hole just large enough for the 

 hand to pass through. The top layers of seeds are further protected 

 by castor oil smeared over them. This prevents the adherence of 

 the egg to the seed, and fails to furnish the larva with the necessary 

 support for boring into it. For small quantities of seed, a little 

 mercury placed in the receptacle is quite effective and does not 

 affect germination. 



Pulse crops may also be stored imder a layer of several inches of 

 grains of Eleusine coracana (ragi) or Panicum frumentaceum (savai), 

 which are not attacked by these beetles. A flat paper disc, closely 

 adjusted to the surface of the seeds and in which semicircular cuts, large 

 enough for the beetles to pass through, have been punched from 

 below, will prevent their return to the seeds, but needs most careful 

 adjustment. The best remedy discovered was to use a narrow- 

 necked receptacle and to cover the seeds with a layer of sand some 

 tw^o inches deep. The seeds should be left for at least a month before 

 any are withdrawn, to allow time for any adults emerging from 

 infested seeds to come to the top and die. 



This latter remedy probably has a wider application, for the same 

 instinct to seek the top surface has been found in such widely differing 

 species as Tribolium castaneum, Lasioderma serricorne, Calandra 

 oryzae, Gibhium scotias and RJdzopertha dominica, though whether 

 the sand layer would be effective against them has not been tested. 



Other beetles infesting stored pulses in Mysore are Bruchus analis, 

 which attacks cow-peas for preference, B. quadrimaculatus, which 

 has been taken in the field in seeds of lablab [Dolichos lablab] in open 

 pods, and multiplies in the stores, but only under moist conditions, 

 and an unidentified species that also infests stored lablab. The 

 identification of these species should be regarded as provisional. 



NowELL (W.). The Red Ring or Root Disease of Coconut Palms. — 



West Indian Bull., Barbados, xvii, no. 4, 1919, pp. 189-202, 

 9 plates. [Eeceived 19th December 1919.] 



Red ring or root disease of coconut palms is believed to be caused 

 by a Nematode, the reason for this belief being that the worms are 

 invariably associated with the initial stages of the disease. They 

 breed in the zone of the stem known as the red ring, and infest the 

 leaf-petioles, and are also associated with a discoloured condition 

 of the roots. The red zone is most developed at the base of the stem 

 and diminishes in intensity towards the apex where it is represented 

 by scattered red dots containing Nematodes and their eggs. It is 

 thought that the disease can be communicated from one tree to 

 another. It is advisable not to plant nuts that have been lying on 

 the ground in the neighbourhood of infested trees and to destroy 

 promptly all infested palms, especially those in the early stages of 

 the disease. Suggestions are also made for detecting infested trees 

 and for protecting young trees in the field. 



