182 TBINIDAD AND TOBAGO BULLETIN. [XIX. 4. 



Parasol or Pot Ants {A. octospinosa) do not live in communities like 

 the Bachacks and the nest generally consists of only one chamber in 

 the gi'ound. These ants also make use of any cavities in walls, under 

 rotten logs of wood, tubs and flower pots ; provided moisture conditions 

 are suitable they will take advantage of any dark and quiet corner in 

 field or garden. 



Parasol ants are not of much importance on estates, they are more 

 injurious about gardens. 



The queens are half an inch long and reddish brown in colour ; there 

 are no ' soldiers ' and the workers vary from a little over a quarter to 

 one-eighth of an inch in length. 



The two species differ in feeding habits : Atta cephalotes seems to 

 confine itself mostly to leaves, but Atta octospinosa will take flowers of 

 different kinds in addition to young leaves as well as the skin of ripe 

 cocao pods. 



Control. — Nests may be destroyed by the use of carbon bisulphide 

 when very big or by means of cyanide of potassium or sodium when 

 small. The most favourable time for dealing with nests is at the 

 end of the dry season just before the rains set in and before the 

 winged ants swarm. In using carbon bisulphide for large nests select 

 only the exits in use by the ants and stop up all other holes with wet 

 earth. Pour into each hole a measured quantity of carbon bisulphide 

 (from a half to one fluid ounce is enough) and allow a little time for 

 the gas to difl'use in the nest ; explode at the mouth of one hole with 

 a match and cover all other holes with wet earth immediately after the 

 explosion in order to put out the fire and confine the fumes. If this is 

 not done a large portion of the gas will be burned and the efficiency of 

 the treatment lessened thereby. 



For small nests of Bachacks and Parasol Ants use cyanide of 

 potassium, one ounce in a gallon of water or crush the same quantity of 

 cyanide and bury in the nest. Carbon bisulphide and cyanide will 

 damage the roots of growing plants. 



THE CACAO BEETLE. 



The Cacao beetle {Steirasloma depressuni) is sufficiently well 

 known to need no description, but fig. 1 represents an adult and 

 fig. 2 B the larva or ' worm ' as it is commonly called here. The 

 principal damage is done by the worms, young trees suffering most 

 from them. The beetles gnaw the young branches for the purpose 

 of feeding on the bark ; the scars which they leave, illustrated in 

 fig. 3, 2 ■■'-, do not damage the tree materially but serve the purpose 

 of indicating where beetles are active and where the worms are to be 

 searched for and destroyed. Feeding and egg laying generally proceed 

 together. Occasionally beetles are found feeding on ripe cacao pods on 

 the trees and on broken pods in the heaps, but this habit is rather rare. 

 Both beetles and worms are more active during dry weather : excessive 

 rain keeps them down. The beetles like sunshine, remaining dormant in 



