Oct. 18, 2013
Termites are important pests of trees, particularly orchard trees such as mango, durian; commercial plantation crops such as rubber trees, oil and coconut palm and landscape trees in Philippines. Though termites may not the primary agents responsible for any damage to the trees, they generally find access to the trees when they are in weaker conditions due to some other causes. The principal food of the termites is fibrous material (cellulose). The worker termites feed on root, shoots and trunks of the trees which sometimes dries up if severely damaged, leading to loss of productivity or simply destruction of the trees.
The cost of damage has never been estimated but could be estimated to be in millions of peso annually. Traditional methods of controlling termites by soil treatment with insecticides and termiticides are frequently not suitable due to difficulties in creating and maintaining a soil barrier. This situation has been further aggravated by the withdrawal of the persistent organochlorines as soil barrier treatments from the market. The replacement termiticides now available are less persistent, thus application in soil leaves the trees under continuous risk and requiring repeated treatments.
Subterranean termites which include Microcerotermes losbañosensis, Macrotermes. gilvus, Coptoterme gestroi and Nasutitermes luzonicus, are the major groups of termites that cause various types of damage to trees and plantation crops in the Philippines. The current major groups of chemicals being used by pest control applicators as chemical barriers include organophosphates, synthetic pyrethroids, a chlornicotinyl and a phenylpyrazole. They are relatively effective to protect the trees but poses danger to the health of applicators, environment and side effect to non-target soil borne organisms.
Termite baiting has evolved in recent times as a sustainable method for managing termites in plantations. Termite baiting involves the application of above ground baiting stations containing bait matrix on the mud tubes and mud galleries of the active termites on tree trunks and also termite mounds. This technique makes use of the inherent termite behaviors of interdependence, trophallaxis, mutual grooming and cannibalism to distribute the bait toxicant throughout the colony, resulting in population loss and colony elimination.
A number of bait toxicants and baiting systems have been developed and evaluated over the last few years for the control of subterranean termite species, but the most efficacious one tested by the author is the Requiem termite bait. The product is manufactured by Ensystex Inc. (NC, USA) and uses the toxicant chlorfluazuron in its bait matrix (1gm of Chlorfluazuron per kg of bait Matrix. Chlorfluazuron is a benzoylphenyl urea that acts as a potent chitin synthesis inhibitor, across various orders of insects including termites. Termites affected by chlorfluazuron also stops feeding on timber possibly due to softening of their mouthparts, leading to starvation and death. The extremely small amount of active ingredient used in accomplishing termite control is also available in two local studies conducted by Garcia (2004 and 2007). The work clearly proves that colony elimination of four species of urban termites in the Philippines can be achieved by application of a very small amount of the active ingredient within 8-12 week time.
This author estimates that baiting technique occupies 25% of the post construction market in urban pest control when gross revenue is considered. This technology has proven its success in urban environment around the world and is most considerate when environment is concerned. However the use of baits in agriculture is never tested seriously. It also could lead to question that baiting may not be cost efficient. This is due to the fact that baiting has been made available to control termites in urban environment till date by various manufacturers. Given the volume of potential business in agriculture, the same manufacturers could easily reduce the cost of the product and realize the possibility of profiting by capturing a significant and new market.
Garcia CM et al (2007) Termite baiting system: A new dimension of termite control in the Philippines. Presented at 38th International Research Group on Wood Preservation in Stockholm. IRG/WP 07-10608. 12 pp
Garcia, C M (2004). Present status of termite management in the Philippines & Japan. In: Proceedings of the 1st Pacific Rim Termite Research Group Meeting. Penang Malaysia. pp 22.