arquata) is the most important of these. It is fairly common not 
only on cacao but on several other plants. It has been observed 
on mango where it does a certain amount of damage to the young 
fruit and flowers. On cacao it appears to be responsible for the 
withering of some of the young pods. Heliothrips rubrocinctus is 
another Insect seldom absent from cacao estates, but which only 
does occasional damage. It lives and breeds on pods and young 
leaves. 
There are quite a number of species of Ants to be found on 
cacao plantations and they certainly rank immediately after the 
Cacao Beetle (Stezrastoma depressum) in destructiveness. Inhabit- 
ing the ground are the Atta cephalotes LINN., which strip young 
trees of their leaves in a very short time ; before the use of carbon 
bisulphide for destroying their nests, they were very troublesome 
and were the subject of an Ordinance empowering proprietors to 
enter lands of each other to destroy nests. Nowadays they are not 
spoken of much, but the destruction of the nests forms part of the 
regular routine work of every plantation. The other Ant living in 
the ground, but which does a great deal of good, is the hunting 
Ant Eciton foreli and other species, that occasionally sweep through 
estates and destroy numbers of harmful Insects. The tree inhab- 
iting Ants, whose habits have not yet been studied in detail, are 
capable of a great deal of harm in connection with their fondness 
of the secretions of plant lice, Scale-insects, Tree-hoppers and 
Caterpillars of Lycænid Butterflies, 
Among the chief offenders may be mentioned Pheidole radosz- 
kowskit, several species of the genera Cremastogaster, Dolichode- 
rus and Azteca, the two latter being universal and numerous. 
Besides encouraging the sucking Insects mentioned they serve as 
means of spreading fungoid diseases. In connection with sugar 
cane, the next staple product of the island, besides the pests of 
old standing, such as Diatrwa saccharalis and Sphenophorus 
piceus, two Insects deserve special mention, they are a Cercopid 
Tomaspis postica and a Moth Castnia licus. Both of these Insects 
have adapted themselves to sugar cane and have attracted consi- 
derable attention by their numbers. 
Tomaspis postica, or as it is called locally « Froghopper », was so 
destructive in some districts of the island that the Board of Agri- 
culture voted the sum of £ 625 for carrying on experiments for the 
control of these Insects, and it was decided that I should devote 
myself entirely to their study. I have been able to work out their 
life history, illustrations of which will be found on plate XXVII. 
