Preferences of Coptotermes formosanus Shiraki and Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae) among Three Commercial Wood Species

Abstract

The Formosan subterranean termite, Coptotermes formosanus Shiraki, and the Asian subterranean termite, Coptotermes gestroi (Wasmann), are both pests of wood in service in Hawaii and Florida. We conducted a laboratory study using method modified from those described in standard E1-09 of the American Wood Protection Association (AWPA 2009) to assess the termite resistance of three commercially available wood species used in regions of the USA where both termite species occur: Douglas fir, Pseudotsuga menziessii, southern yellow pine, Pinus spp. and redwood, Sequoia sempervirens. A multiple-choice (three-choice) assay was used for four weeks (28 days) in order to simulate field conditions of food choice and assess termite feeding preferences under 28 °C and 72–80% RH. 400 termites (360 workers: 40 soldiers) were released into each test jar. Five replicates and two controls of each wood species were used with each termite species. Termite mortality was recorded at the end of the test; and wood wafers were oven-dried and weighed before and after termite exposure to determine the mass loss due to termite feeding, and rated visually on a 0 (failure) to 10 (sound) scale. There were significant differences in mean mass loss values among the three wood species and between two termite species. The mean mass loss value for redwood was significantly lower than Douglas fir and southern yellow pine with both termite species. However, C. formosanus showed increased feeding on Douglas fir and southern yellow pine compared to C. gestroi.

Do Tunnel Patterns of Coptotermes formosanus and Coptotermes gestroi (Blattodea: Rhinotermitidae) Reflect Different Foraging Strategies?

“…We observed the same interspecific differences in tunneling patterns noted by Grace et al (2004) and Hapukotuwa & Grace (2010, 2011a). Although we were not able to directly relate these tunnel patterns (in terms of tunnel numbers and lengths) to differences in resource usage, the differences in times to locate food noted in this study support the hypothesis of Grace et al (2004) that C. formosanus is able to locate distant resources more efficiently than C. gestroi.…”

“…Shelton and Grace (2003) noted higher mortality rates of C. gestroi than of C. formosanus under desiccating conditions. Uchima & Grace (2003), Grace et al (2004) and Hapukotuwa & Grace (2011b) reported that C. formosanus generally has a higher wood feeding rate than C. gestroi. Uchima & Grace (2009) reported that C. gestroi had higher mortality rates in interspecific agonism and foraging competition experiments with C. formosanus.…”

“…As mentioned, Grace et al (2004) and Hapukotuwa & Grace (2010, 2011a demonstrated that the tropical species C. gestroi constructs a highly branched tunnel network over a fairly limited area, while the subtropical C. formosanus constructs longer and wider tunnels with few branches. Grace et al (2004) hypothesized that this difference in foraging behavior may be related to foraging efficiency in the tropical vs. subtropical environs.…”

“…Coptotermes gestroi makes long, thin, highly branched tunnels; whereas C. formosanus constructs longer, wider, and lessbranched tunnels. These visual observations were subsequently quantified by Hapukotuwa & Grace (2010, 2011a.…”

Assessment of Genetic Markers for the Determination ofCoptotermes formosanus×Coptotermes gestroi(Isoptera: Rhinotermitidae) F1 Hybrids

“…Although both species exhibited similar feeding preferences for different types of lumber (Hapukotuwa and Grace 2011a) and bamboo (Hapukotuwa and Grace 2011b), C. gestroi was found to have a slower feeding rate than C. formosanus (Uchima and Grace 2003b). Coptotermes gestroi also suffers greater mortality than C. formosanus under desiccating conditions (Shelton and Grace 2003).…”