131 



Urich (F. W.). Insects affecting the Avocado in Trinidad and Tobago. 



—Bull Dept. Agric. Trinidad and Tobago, Pod of SjMin, xviii, 

 no. 3, 19th November 1919, pp. 129-131, 2 plates. [Received 

 ITth January 1920.] 



The pests of avocado in Trinidad and Tobago include an ant, 

 Solenopsis geminala, which besides fostering scale-insects and mealy- 

 bugs bites off the young bark from the shoots and stems of young 

 trees. It may be controlled by destruction of the nests with carbon 

 bisulphide and sodium or potassium cyanide. The nests may also 

 be destroyed with boiling water and puddling. A little resin "added 

 to the boiling water greatly increases its efficacy. The trees can be 

 protected by banding with tree tanglefoot and similar mixtures for 

 which the formulae are appended. 



The nests of another ant, Cremastogaster brevispinosa, usually found 

 under loose dried bark and rotten wood resulting from badly dressed 

 pruning wounds or from dead branches left on the trees, should be 

 cut out and the place painted with crude oil or strong resin wash. 



Coccid pests include Pulvinaria pijriformis, Aspidiotus destructor, 

 Sai.ssefia nigra, Pseudococcus nipae and P. citri. If not sufficiently 

 controlled by natural enemies spraying with nicotine sulphate in 

 combination with resin wash or soap is advocated. 



Stericta albifasciata, the caterpillars of which destroy the flowers 

 and young leaves and live in nests made by webbing together 

 the leaves and branches, can only be destroyed by cutting off and 

 burning the nests. Care must be taken that the caterpillars do not 

 disappear during the process, as when alarmed they drop to the ground 

 by means of silken threads and hide. They are parasitised by a 

 Tachinid. 



Williams (C. B.). Rainfall, Sugar Production and Froghopper Blight 

 in Trimdaa.-^Bull. Dept. Agric. Trinidad and Tobago, Port of Spain, 

 xviii, no. 3, 19th November 1919, pp. 153-167, 11 figs. 

 [Received 17th January 1920.] 



Observations extending over many years show that unusual alterna- 

 tions of wet and dry periods and particularly a well-marked dry 

 period in September or October is conducive to a great increase of 

 froghoppers. It is evident that the actual number of insects {Tomaspis 

 saccharina) present in a field is of less practical importance than the 

 general ability of the sugar-cane to withstand the damage, and this 

 condition can only be brought about by improved drainage. 



Jordan (W. H.). Director's Report for 1918.— iVew; Yorh Agric. 

 Expt. Sta., Geneva, N.Y., Bull. 457, December 1918, 25 ' pp. 

 [Received 23rd January 1920.]. 



The entomological work recorded in this report has already been 

 noticed in previous bulletins of the Station [R.A.E., A, vii, 182, 495]. 



Jarvis (E.). Insect Friends of the Cane'gTOwer.^ueensland Agric. 

 Jl, Brisbane, xii, no. 6, December 1919, pp. 301-304, 1 plate. 



This paper is written with the object of enabling sugar-cane growers 

 to recognise the earlier stages of certain useful insects associated with 



