615 



and particles of earth Adults appear about a week later, the cycle 

 retjuiring 21 to 30 days. The only remedial measure that seems 

 feasible is to prevent the larvae from entering the soil by covering 

 the ground under the trees with lime. Moist weather during the 

 dry season seems favourable to the flies. Further investigations arc 

 being made. 



WiLLi.uis (C. B.). Sugar-cane Pests and Diseases in Trinidad in 



1920. — Bull. Dept. Agric. Trinidad & Tobago, Port-of-Spain, 

 xix, no. 3, 1921, pp. 111-121. 



The information in this paper regarding Tomaspis saccharina (sugar- 

 cane froghopper) in Trinidad is supplementary to that previously 

 noticed [R. A.E., A, ix, 261]. The seasonal appearance of, and damage 

 done by, this pest in various localities, and the influence of rainfall, 

 soil and ratooning are discussed. An extensive outbreak of a 

 fungus, EnipKsa, among the froghoppers occurred in November and 

 December 1920. It was probably connected with the large third 

 generation, which appeared unusually late, and with the wet weather 

 experienced in November. 



The present situation with regard to mosaic disease and its effect 

 on the sugar-cane plant is discussed. It was first discovered in 

 Trinidad in 1920, and has since spread considerably. While it is 

 recognised that the disease is spread from diseased to healthy plants 

 chiefly, if not entirely, by insects, it has not yet been definitely deter- 

 mined which insects are capable of transmitting the infection. Species 

 that are proved or suspected carriers in other countries are mostly 

 rare or non-existent in Trinidad. Aphids do not seem to be present 

 on sugar-cane ; the occurrence of Ptdvinaria (leaf scale) is doubtful, 

 and Stenocranns (cane fly) is extremely rare. Tests have been made 

 by transferring from infected to healthy canes individuals of 

 Tomaspis saccharina, Peregrinus maidis (corn leaf-hopper), a 

 cane leaf-hopper, Tettigoniella laudata and the cane Membracid, 

 Ceresa vitulus, F., var. minor, Fowl., but in no case was the disease 

 transmitted. The only other insect that seems sufficiently abundant 

 to account for the known spread is a mealybug [Pseitdococcus~\, and 

 experiments with this are proceeding. 



HuTsoN (J. C). Report of the Division of Entomology, April-June, 



1921. — Trop. Agric, Pcradeniva, Ivii, no. 3, September 1921, 

 p. 194. 



Odoiporiis longicollis (weevil stem-borer) and Cosniopolites sordidns 

 (weevil bulb-borer) were prevalent on bananas, especially in plantations 

 maintained for more than two years without replanting. An out- 

 break of the Limacodid, Natada nararia (fringed nettle-grub) in June 

 on tea was investigated, and the caterpillars were found feeding on 

 inter-planted dadap and other plants. 



The following insects have been reported during the quarter : — 

 Homona coffearia (tea tortrix), Batocera rnbus (rubber stem and root 

 borer), Schoenobius incertellus (paddy stem-borer), Terastia mcticulo- 

 salis (dadap shoot-borer), Hypsipyla robitsta (toona shoot-borer), 

 mango fruit fly {Dacits sp.), and Ccroplastodcs cajani on Tcphrosia 

 Candida. Special investigations are in progress on the termites, Calo- 

 termes militaris, Spodoptcra maiiritia (paddy swarming caterpillar) 

 and Aularches miliar is (spotted locust). 



