54 



JOURNAL OF THE ROIAL H(^)lvnCULTUKAL SOCIETY. 



of the genus Solciiopsis. It li;is Ihhmi inipoyyihlo h^o fur to g(>li lliis 

 insect identified in iliis couuli \ , hut il is in ;dl |)it)l);il)ilily Jviiowii Lo 

 the American entomologists. In its nest-bulldmg habits it resembles 

 the terrestrial species of Foniiica aiid oilier allied genera found in the 

 British Isles and in other parts of the world. The nests of tlie 

 species in question were, however, generally constructed so that 

 they were partly protected from the direct rays of the tropical sun, 

 being sometimes completely overshadowed by the cacao tress. In the 

 Ohapelton district their nests were found scattered all over the planta- 

 tions, and the ants were found foraging about the branches of a very 

 large percentage of the cacao trees. The nests were often placed close 

 to the trees on wliich the ants were found wandering about ; but in 

 several instances these structures were also found on the outskirts of 

 the plantation without apparently any regard to the distance the ants 

 had to travel in order to reach their feeding-grounds. 



Many of the trees were found swarming with these insects, but it 

 was some time before one could obtain any clue to the object of 

 their search. Eventually it was discovered that they were attracted 

 by the " honey dew " secreted by small colonies of plant lice (Aphidae) 

 which were feeding upon the leaves of the cacao, generally speaking, 

 at some considerable distance from the main stern and branches. In 

 order, apparently, to screen their movements, the ants constructed 

 for themselves a narrow gallery or covered way leading from the 

 ground up to a point where the branches diverge from the main stem 

 or trunk or sometimes even to a greater elevation. The gallery was in 

 all cases formed of pellets of earth, of a very fragile nature and easily 

 removed. Having reached the main branches of the cacao under cover 

 the insects sought further protection by forming larger covered ways 

 among the dead flowers which had accumulated in the bifurcations 

 of the branches and also among the clusters or " cushions " of flowers 

 upon the main branches. In the latter case the pedicels of the flowers 

 had apparently been injured in such a way as to prevent them falling 

 from the tree, so that they remained in situ, shrivelled and dry, for 

 indefinite periods, forming excellent retreats for the ants. 



From these shelters they seemed to be constantly moving to and 

 fro among the upper branches of the cacao, seeking for the sweet juice 

 secreted by the aphides. The dead flower-clusters were easily removed 

 and, although carefully examined, did not appear to be cemented 

 together by soil or other substances. At first one suspected that the 

 flowers had died from some unknown disease, but after careful in- 

 vestigation one came to the same conclusion as the planter, that they 

 were destroyed by the ants. This was confirm-ed by the fact that the 

 dead " cushions " always occurred upon the lower portions of the main 

 branches, and that they were invairiably tenanted by these insects. 

 The loss occasioned in this way was often considerable, and several 

 methods of checking their ravages had been attempted with, unfortu- 

 nately, but little success. 



A mixture of lime, kerosene, turpentine, &c., had been tried as a 



