Nirmala K. Hapukotuwa and J. Kenneth Grace
Dept. of Plant and Environmental Protection Sciences
University of Hawaii at Manoa
Introduction
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Bamboo
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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
World distribution of bamboo
Source: Ohrnberger 1999
 Advantages of bamboo for construction:
1.
2.
3.
4.
5.
Suitable strength (fibrous texture)
Preferential cost
Fast growth
Easy availability
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
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Furniture
Ornaments
Construction materials-Mainly fencing, flooring
Musical instruments
Some uses of bambo0
 Coptotermes formosanus:
 Present in Hawaii for over 100 years
 Probably introduced from southern China
 Major termite pest in Hawaii
 Widely distributed
C. formosanus
 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)
C. gestroi
Objective:
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To determine relative resistance of six different bamboo
species grown in Hawaii to C. formosanus and C. gestroi
Materials and Methods
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Single choice (no choice) test
Standard E1-09 of the American Wood Preservation Association
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Six bamboo species;
1.
2.
3.
4.
5.
6.
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”
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Wood blocks
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2.5 x 2.5 x 0.5 cm in size
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Five replicates of each bamboo species with each
termite species
Set-up
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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 mortality
 reweighed blocks after oven drying
 Visually rated blocks according to the 2009 AWPA rating scale
Results
Sample test jars:
1.
C. formosanus
2.
C. gestroi
1
2
1
2
Sample visual ratings for C. formosanus
Rating scale: 4=very severe, 50-75% affected; 7=moderate, 10-30% affected
Sample visual ratings for C. gestroi
Rating scale: 4=very severe, 50-75% affected; 7=moderate, 10-30% affected
 Summary of results for C. formosanus
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a Values
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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).
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).
 Summary of results for C. gestroi
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a Values
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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).
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).
Mean mass loss of six different bamboo species exposed to
C. formosanus or C. gestroi.
Mean percent mortality of C. formosanus and C. gestroi
after exposure to six different bamboo species
Conclusions
 Mean mass losses of bamboo due to termite feeding for
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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
Acknowledgements
Reina
Dr J. Kenneth Grace
Makena
Maria
Rob
Thank you!