Abstract
1. The report covers a period of 3½ years actually spent in the field.2. During this time 19 major pests have been studied, with special reference to their natural enemies and other limiting factors. The pests of sugar-cane have, however, received by far the most attention, partly because this is the most important crop throughout the region as a whole, and partly because the industry has made substantial financial contributions.3. Advice has been given, on request, to local Governments, planters' organisations and individual planters, and schemes have been drawn up for intensive local research on cane-borers, on froghopper and on mongoose. The researches of the two investigators of the cane-borer (Diatraea spp.), under grants from the Colonial Development Fund, have been supervised so far as their technical aspect is concerned.4. For the control of the small moth-borer (Diatraea) the most important pest of sugar-cane as a whole, the Cuba fly (Lixophaga) has been introduced (in collaboration with Mr. Box) into the Leeward and Windward Islands, and the Amazon fly (Metagonistylum) into British Guiana (in collaboration with Mr. Cleare). Both these very promising parasites, the second of which was discovered during the course of the investigation, are now widely established.5. A specific parasite is now needed for Diatraea canella in British Guiana and D. impersonatella in Trinidad. It is possible that experiments now in progress (in collaboration with Mr. Pickles and Mr. Cleare respectively) that Paratheresia will serve for the first and Metagonistylum for the second, but a highly specific parasite for D. canella remains greatly desirable.