A method of controlling termite colonies that live within plants.
Postelectrotermes militaris (Desn.), Neotermes greeni (Desn.) and Glyptotermes dilatatus (Bugnion & Popoff) are important pests of tea in Sri Lanka [cf. RAE/A 52, p. 491] and are difficult to control because they develop and feed in the heartwood of stems and branches (and P. militaris also in the roots) and the colonies are well-protected. The authors describe in detail a method developed for the control of these termites, based on the introduction of a fumigant through a hole drilled into each gallery system. Among various fumigants tested, the best results were obtained with Phostoxin tablets and pellets. These contain aluminium phosphide, which gives off phosphine on exposure to moisture. To control Postelectrotermes, which has a large gallery system, 1.2 g Phostoxin/gallery (2 pellets each of 0.6 g or half a tablet weighing 3 g) was necessary, but for Glyptotermes, which has a smaller system, rates of 0.15-0.3 g Phostoxin/gallery were effective. Complete control was obtained in virtually all tests, the few failures being attributed to possible misplacement of the chemical or inadequate sealing of openings after its introduction. Promising results are also obtained with ethylene dibromide and trichlorobenzene. It is considered that this method should prove useful for the control of termites attacking other crops and forest trees.