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Nirmala K. Hapukotuwa and J. Kenneth Grace Dept. of Plant and Environmental Protection Sciences

Nirmala K. Hapukotuwa and J. Kenneth Grace Dept. of Plant and Environmental Protection Sciences University of Hawaii at Manoa. Introduction. Bamboo Versatile forest based natural resource More than 1500 species described Plays an important role in the national

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Nirmala K. Hapukotuwa and J. Kenneth Grace Dept. of Plant and Environmental Protection Sciences

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  1. Nirmala K. Hapukotuwa and J. Kenneth Grace Dept. of Plant and Environmental Protection Sciences University of Hawaii at Manoa

  2. Introduction • Bamboo • Versatile forest based natural resource • More than 1500 species described • Plays an important role in the national economy of many countries, especially in the tropics • Primarily used as a construction material

  3. World distribution of bamboo Source: Ohrnberger 1999

  4. Advantages of bamboo for construction: • Suitable strength (fibrous texture) • Preferential cost • Fast growth • Easy availability • Light and smooth (easy to transfer)

  5. Bamboo (‘Ohe) in Hawaii • May have been introduced by ancient Polynesians • Approximately 70 species and varieties • Mainly used for • Furniture • Ornaments • Construction materials-Mainly fencing, flooring • Musical instruments

  6. Some uses of bambo0

  7. C. formosanus • Coptotermes formosanus: • Present in Hawaii for over 100 years • Probably introduced from southern China • Major termite pest in Hawaii • Widely distributed

  8. C. gestroi • Coptotermes gestroi: • Intercepted in banana shipments to Hawaii (1934) • Major pest in the Philippines and in Guam • First discovered on Oahu in 1963 (single home) • Re-discovered on Oahu in 1999 • Currently has limited but expanding distribution (southwest Oahu)

  9. Objective: • To determine relative resistance of six different bamboo species grown in Hawaii to C. formosanus and C. gestroi

  10. Materials and Methods • Single choice (no choice) test Standard E1-09 of the American Wood Preservation Association • Six bamboo species; • Bambusa hirose(BH)-Hirose’s bamboo • B. oldhamii (BO)-Giant timber bamboo • Dendrocalamus brandisii (DB)-Sweet dragon bamboo • D. latiflorus (DL)-Sweet giant bamboo • Gigantocholoa pseudoarundinacea(GP)-Great giant bamboo • Guadua angustifolia(GA)-”Guadua”

  11. Wood blocks • 2.5 x 2.5 x 0.5 cm in size • Five replicates of each bamboo species with each termite species • Set-up • Polystyrene jars (height 97 mm, diameter 85 mm) • Each contained 150 g silica sand, 30 ml distilled water and bamboo block

  12. C. gestroi: Kalaeloa field site (9 m above sea level; annual rainfall 20.9 in; annual mean temperature 75.6 F) C. formosanus: Miller Hall, UH Manoa (23.1 m above sea level; annual rainfall 105.2 in; annual mean temperature 69.5 F)

  13. 200 freshly collected termites (180 workers / 20 soldiers) added to each test jar • All jars placed in an unlighted incubator for 28 days (280C) • Jars inspected each week to record termite activity and tunneling patterns • After 28 days, all jars disassembled • counted live termites (workers & soldiers) to determine mortality • reweighed blocks after oven drying • Visually rated blocks according to the 2009 AWPA rating scale

  14. Results • Sample test jars: • C. formosanus • C. gestroi 2 1 1 2

  15. Sample visual ratings for C. formosanus Rating scale: 4=very severe, 50-75% affected; 7=moderate, 10-30% affected

  16. Sample visual ratings for C. gestroi Rating scale: 4=very severe, 50-75% affected; 7=moderate, 10-30% affected

  17. Summary of results for C. formosanus a Values in parentheses are standard deviations; means within a column followed by the same letter are not significant at the 5% level (ANOVA,Tukey’s HSD). Rating: 10 (sound), 9.5 (trace, surface nibbles permitted), 9 (slight attack up to 3% of cross sectional area affected), 8 (moderate attack, 3-10 % of cross sectional area affected), 7 (moderate/severe attack, penetration, 10-30% of cross sectional area affected), 6 (severe attack,30-50% of cross sectional area affected), 4 (very severe attack, 50-70% of cross sectional area affected) or 0 (failure).

  18. Summary of results for C. gestroi a Values in parentheses are standard deviations; means within a column followed by the same letter are not significant at the 5% level (ANOVA,Tukey’s HSD). Rating: 10 (sound), 9.5 (trace, surface nibbles permitted), 9 (slight attack up to 3% of cross sectional area affected), 8 (moderate attack, 3-10 % of cross sectional area affected), 7 (moderate/severe attack, penetration, 10-30% of cross sectional area affected), 6 (severe attack,30-50% of cross sectional area affected), 4 (very severe attack, 50-70% of cross sectional area affected) or 0 (failure).

  19. Mean mass loss of six different bamboo species exposed to C. formosanus or C. gestroi.

  20. Mean percent mortality of C. formosanus and C. gestroi after exposure to six different bamboo species

  21. Conclusions • Mean mass losses of bamboo due to termite feeding for four weeks ranged from 14-29% • Most resistance bamboo species were Gigantocholoa pseudoarundinacea and Bambusa oldhamii • Most susceptible bamboo species was Guadua angustifolia • Bambusa hirose, Dendrocalamus brandisii and D. latiflorus were intermediate in their termite resistance • Overall, there appeared to be little difference in feeding preferences between C. formosanus and C. gestroi

  22. Acknowledgements Reina Dr J. Kenneth Grace Makena Maria Rob

  23. Thank you!

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