The significance of fungal decay of eucalyptus regnas F muell heartwood for some aspects of the biology of coptotermes lacteus (froggatt)

Abstract

The biology of the termite Coptotermes lacteus (Froggatt) was investigated with the hope of understanding the basis for this species preferential attack of decaying rather than sound wood. Six wood rotting basidiomycetes, three brown rots, Coniophora olivacea (Fr.) Trametes lilacino-gilva (Berk.) Lloyd and Gloeophyllum trabeum (Pers. ex Fr.) Murr.and three white rots- Perenniporia tephropora (Mont.) Ryv., Pycnoporus coccineus (Fr. ) Bond & Singer and Tinctoporellus epimiltinus (Berk. & Br.) Ryv., were used to inoculate Eucalyptus regnans F. Muell. heartwood. Interspecific differences in fungal decomposition rate and wood consumption by termites were examined. Fungal species was a significant factor in determining wood consumption and termite survival. Wood consumption was inversely related to termite survival. Termites maintained on wood inoculated with T. lilacino-gilva had the highest consumption rate and the lowest mortality level. Brown rots in general were found to enhance termite colony development. The amount of nitrogen in the wood could not be related to colony development as it did not vary significantly between the wood treatments used to investigate that aspect of termite biology. Nonetheless, there was a trend towards greater wood consumption at higher nitrogen levels. The preference of C. lacteus for wood inoculated with T. lilacino-gilva has the potential to be used in the development of integrated termite control based on using wood treated in such a fashion as a biological bait. This would allow a reduction in the amount of toxic chemicals currently being applied which would have both ecological and economic advantages.