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

World distribution of bambooSource: Ohrnberger 1999

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

Some uses of bambo0

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

Results

1 2

1 2

Sample test jars:

1. C. formosanus

2. C. gestroi

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

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

Acknowledgements

Rob

Maria

Reina

Makena

Dr J. Kenneth Grace

Thank you!