STUDIES ON WOOD PREFERENCES OF TERMITES

Abstract

1. Seventeen different types of timbers were selected to study wood preferences 2. Uood preferences of C under laboratory conditions were studied. BaSed on the propensity of woods are arranged in descending order of preference. highly resistant to attack of termites.

3. Wood eating preferences of Odonto?tern.es obesus based 011 field experiments showed were found highly resistant. however, was consumed considerably by 4? Wood consumption by Qo_ptot?es heim?. at 25°C under different relative hwnidities was studied. Copt2?ter11?? showed maximum feedins; under 96 % relative humidity. 5. Effect of temperature on the natural resistance of is described in detail• which is highly resistant to attack of termites, lost its resistance due to heat. Termites showed maximum on wooden. blocks dried at 60°C and 100°C. 6. Laboratory and field experiments with a highly palatable· and a highly resistant timber were carried out to see the influe1_1ce of specimen size on the amount of wood consumed

by termites. nean amounts consumed by termites were si6ni- ficantly different where the differences in specimen

lengths were 3 times or more. 7. Feeding responses to wood extracts and essential oil are described? Such studies ha not been carried out so far in Pakistan and even· in India·•. Wood extrac t and essential oil of Pinus walli2.E..iana w ?ighly unpalat2ble

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and tern?icidal to OdontoJ...ermes ?--???? and Co_p-4t_o.ter?? :l??t!ll-., but Bifiditermes beesoni was not effected. 8, Ylood extract and essential oil of Cedr?. ?-?o.q.? is hi8hly toxic to Od(?A?E???}?·m??s .?J)??u.s., Co_pt2_!.?!El?E. .?2-1.:'1? a d ?Bifiditerrnes beesoni. Cedrus deodare is highly resisto.1t ..............?----? .___.._...?.. -.. -- ... .........._.....? ?-------.-? rather toxic to termit.es and owns this quality becauoe e>f its essenti?l oil which is lost due to heat, rendering it susceptible to attack of termites. 9 • -Heart wood extract and essential oil of Dalber_gj.a sissoa. effected the survival of Odcwtotermes obesus and 9.££toter? heimi • but Bifiditermes bee.soni remained une ff'ect cd , 1:iooden b lock of the heartwood of Dalbergia sissocJ, however, stroncly resisted t he attack of t e rmit es • It s nat ura 1 resistance Qan be attributed mostly to its hardness ani partly t o its chemical scrnponent s , 10. Extract preferene,.es of termites were aLso studied, · Extract of the least preferred portion of the wood was also least preferred when termites were confined to filter papers treated with extracts.