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Comparative Study of the Resistance of Six Hawaii-Grown Bamboo Species to Attack by the Subterranean Termites Coptotermes formosanus Shiraki and Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae).

Hapukotuwa NK, Grace JK - Insects (2011)

Bottom Line: Mean mass losses of the six species as a result of termite feeding ranged from 13-29%; with the two most resistant bamboo species, Gigantocholoa pseudoarundinacea and Bambusa oldhamii, demonstrating significantly greater resistance to termite attack than the most susceptible bamboo species, Guadua anguistifolia, with both termite species.Overall, we observed very little difference in wood preference between C. formosanus and C. gestroi.Although bamboo is a very promising construction material, and species clearly differ in their susceptibility to termite attack, all six species evaluated in the present study would require additional protection for use under conditions of high termite pressure.

View Article: PubMed Central - PubMed

Affiliation: College of Tropical Agriculture & Human Resources, University of Hawaii at Manoa, 3050 Maile Way, Gilmore Hall 310, Honolulu, HI 96822, USA. nirmala@hawaii.edu.

ABSTRACT
Bamboo is widely grown and utilized as a construction material around the world, particularly in the tropics. At present, there are about 70 bamboo species and varieties recorded from Hawaii. The objective of our study was to determine the relative resistance of six Hawaii-grown bamboo species to attack by Coptotermes formosanus Shiraki and Coptotermes gestroi (Wasmann). Four-week laboratory feeding trials were performed as described in standard E1-09 of the American Wood Protection Association (AWPA 2009). Samples of each of the six bamboo species were individually exposed to 200 termites (with 10% soldiers); and termite mortality, wood mass loss, and visual appearance of the samples (on a scale of 0-10) were recorded at the conclusion of the trail. Mean mass losses of the six species as a result of termite feeding ranged from 13-29%; with the two most resistant bamboo species, Gigantocholoa pseudoarundinacea and Bambusa oldhamii, demonstrating significantly greater resistance to termite attack than the most susceptible bamboo species, Guadua anguistifolia, with both termite species. Dendrocalamus brandisii, Dendrocalamus latiflorus, and Bambusa hirose were intermediate in their termite resistance. Overall, we observed very little difference in wood preference between C. formosanus and C. gestroi. Although bamboo is a very promising construction material, and species clearly differ in their susceptibility to termite attack, all six species evaluated in the present study would require additional protection for use under conditions of high termite pressure.

No MeSH data available.


Sample test jars of C. formosanus (left) and C. gestroi (right).
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f1-insects-02-00475: Sample test jars of C. formosanus (left) and C. gestroi (right).

Mentions: As has been previously noted by Grace et al. [17], we observed some differences between C. formosanus and C. gestroi in tunneling patterns (Figures 1 and 2). Coptotermes gestroi made a greater number of narrow and highly branched tunnels, while C. formosanus made fewer, and less branched tunnels. In addition, C. gestroi constructed tunnels all the way to top of all jars within first three weeks; but C. formosanus made very few tunnels to the top of only a few jars within this same time period. Within the first two weeks, both termite species were very active in tunneling and moved onto the bamboo wafers. During the first week of observations, C. gestroi showed very light feeding on Bambusa hirose, B. oldhamii, D. latiflorus, and Guadua angustifolia; whereas C. formosanus caused no visible damage to any bamboo wafer. During the second week of inspection, C. gestroi did heavy damage to B. oldhamii and Guadua angustifolia However, C. formosanus exhibited light damage to all the bamboo types, except D. latiflorus and Dendrocalamus brandisii which had moderate damage. Since some of the wafers with both termite species were covered with sand, we had some difficulty in visually estimating feeding rates. During the third and fourth weeks, both termite species exhibited less tunneling activity but relatively high feeding activity. Coptotermes formosanus in particular showed heavy feeding on Bambusa hirose and Guadua angustifolia. Also, we observed that all of our test samples were invaded by the termites from the cut sides and through the inner layer, rather than directly through the exterior surface. The reason for this pattern of attack may be that the outer layer of bamboo has a considerable amount of ash and silica [18,19], and that these compounds help in improving natural durability as well as in imparting strength to bamboos [13].


Comparative Study of the Resistance of Six Hawaii-Grown Bamboo Species to Attack by the Subterranean Termites Coptotermes formosanus Shiraki and Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae).

Hapukotuwa NK, Grace JK - Insects (2011)

Sample test jars of C. formosanus (left) and C. gestroi (right).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4553440&req=5

f1-insects-02-00475: Sample test jars of C. formosanus (left) and C. gestroi (right).
Mentions: As has been previously noted by Grace et al. [17], we observed some differences between C. formosanus and C. gestroi in tunneling patterns (Figures 1 and 2). Coptotermes gestroi made a greater number of narrow and highly branched tunnels, while C. formosanus made fewer, and less branched tunnels. In addition, C. gestroi constructed tunnels all the way to top of all jars within first three weeks; but C. formosanus made very few tunnels to the top of only a few jars within this same time period. Within the first two weeks, both termite species were very active in tunneling and moved onto the bamboo wafers. During the first week of observations, C. gestroi showed very light feeding on Bambusa hirose, B. oldhamii, D. latiflorus, and Guadua angustifolia; whereas C. formosanus caused no visible damage to any bamboo wafer. During the second week of inspection, C. gestroi did heavy damage to B. oldhamii and Guadua angustifolia However, C. formosanus exhibited light damage to all the bamboo types, except D. latiflorus and Dendrocalamus brandisii which had moderate damage. Since some of the wafers with both termite species were covered with sand, we had some difficulty in visually estimating feeding rates. During the third and fourth weeks, both termite species exhibited less tunneling activity but relatively high feeding activity. Coptotermes formosanus in particular showed heavy feeding on Bambusa hirose and Guadua angustifolia. Also, we observed that all of our test samples were invaded by the termites from the cut sides and through the inner layer, rather than directly through the exterior surface. The reason for this pattern of attack may be that the outer layer of bamboo has a considerable amount of ash and silica [18,19], and that these compounds help in improving natural durability as well as in imparting strength to bamboos [13].

Bottom Line: Mean mass losses of the six species as a result of termite feeding ranged from 13-29%; with the two most resistant bamboo species, Gigantocholoa pseudoarundinacea and Bambusa oldhamii, demonstrating significantly greater resistance to termite attack than the most susceptible bamboo species, Guadua anguistifolia, with both termite species.Overall, we observed very little difference in wood preference between C. formosanus and C. gestroi.Although bamboo is a very promising construction material, and species clearly differ in their susceptibility to termite attack, all six species evaluated in the present study would require additional protection for use under conditions of high termite pressure.

View Article: PubMed Central - PubMed

Affiliation: College of Tropical Agriculture & Human Resources, University of Hawaii at Manoa, 3050 Maile Way, Gilmore Hall 310, Honolulu, HI 96822, USA. nirmala@hawaii.edu.

ABSTRACT
Bamboo is widely grown and utilized as a construction material around the world, particularly in the tropics. At present, there are about 70 bamboo species and varieties recorded from Hawaii. The objective of our study was to determine the relative resistance of six Hawaii-grown bamboo species to attack by Coptotermes formosanus Shiraki and Coptotermes gestroi (Wasmann). Four-week laboratory feeding trials were performed as described in standard E1-09 of the American Wood Protection Association (AWPA 2009). Samples of each of the six bamboo species were individually exposed to 200 termites (with 10% soldiers); and termite mortality, wood mass loss, and visual appearance of the samples (on a scale of 0-10) were recorded at the conclusion of the trail. Mean mass losses of the six species as a result of termite feeding ranged from 13-29%; with the two most resistant bamboo species, Gigantocholoa pseudoarundinacea and Bambusa oldhamii, demonstrating significantly greater resistance to termite attack than the most susceptible bamboo species, Guadua anguistifolia, with both termite species. Dendrocalamus brandisii, Dendrocalamus latiflorus, and Bambusa hirose were intermediate in their termite resistance. Overall, we observed very little difference in wood preference between C. formosanus and C. gestroi. Although bamboo is a very promising construction material, and species clearly differ in their susceptibility to termite attack, all six species evaluated in the present study would require additional protection for use under conditions of high termite pressure.

No MeSH data available.