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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 - PowerPoint PPT Presentation
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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
economy of many countries, especially inthe tropics
Primarily used as a construction material
Advantages of bamboo for construction:
1. Suitable strength (fibrous texture)2. Preferential cost3. Fast growth4. Easy availability5. Light and smooth (easy to transfer)
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
Coptotermes formosanus:Present in Hawaii for over 100 yearsProbably introduced from southern ChinaMajor termite pest in HawaiiWidely distributed
C. formosa
nus
Coptotermes gestroi:Intercepted in banana shipments to Hawaii
(1934)Major pest in the Philippines and in GuamFirst discovered on Oahu in 1963 (single home)Re-discovered on Oahu in 1999Currently has limited but expanding
distribution (southwest Oahu)
C. gestroi
Objective: To determine relative resistance of six different
bamboo species grown in Hawaii to C. formosanus and C. gestroi
Materials and Methods Single choice (no choice) test
Standard E1-09 of the American Wood Preservation Association
Six bamboo species;1. Bambusa hirose (BH)-Hirose’s bamboo2. B. oldhamii (BO)-Giant timber bamboo3. Dendrocalamus brandisii (DB)-Sweet dragon bamboo4. D. latiflorus (DL)-Sweet giant bamboo5. Gigantocholoa pseudoarundinacea (GP)-Great giant
bamboo6. Guadua angustifolia (GA)-”Guadua”
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
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)
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
mortalityreweighed blocks after oven dryingVisually rated blocks according to the 2009 AWPA rating
scale
Sample visual ratings for C. formosanusRating scale: 4=very severe, 50-75% affected; 7=moderate,
10-30% affected
Sample visual ratings for C. gestroiRating scale: 4=very severe, 50-75% affected; 7=moderate,
10-30% affected
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).
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).
Mean percent mortality of C. formosanus and C. gestroiafter exposure to six different bamboo species
ConclusionsMean mass losses of bamboo due to termite feeding
for four weeks ranged from 14-29%Most resistance bamboo species were Gigantocholoa
pseudoarundinacea and Bambusa oldhamiiMost susceptible bamboo species was Guadua
angustifoliaBambusa 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