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

Nirmala K Hapukotuwa,J Kenneth Grace

doi:10.3390/insects2040499

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.

Highlights

Termite feeding activities play an important role in nutrient and energy cycles in ecosystems [1].Numerous experiments have been conducted to study their foraging behavior, feeding preferences, feeding rates, etc
During the first weekly inspection period we observed that both species of termites contacted all types of wood, and some moved to the bottom of the jars and began to make tunnels
Both species began to feed upon Douglas fir and southern yellow pine

Summary

Introduction

Termite feeding activities play an important role in nutrient and energy cycles in ecosystems [1]. Numerous experiments have been conducted to study their foraging behavior, feeding preferences, feeding rates (wood consumption rates), etc. Subterranean termites have very efficient searching systems [3] consisting of branching gallery systems, with the architecture and speed of construction of the system varying among species. These gallery systems have been excavated and have been mapped by different researchers using laboratory foraging arenas. The purposes of our study were to compare feeding rates and wood feeding preferences of these two termite species using a multiple choice test modified from AWPA (2009). Comparing wood preferences is useful for selecting building materials for use under conditions of high termite hazard, and to identify wood species requiring preservative treatment before use

Materials and Methods

Wood Blocks

Test Design

Bioassays and Termites

Results and Discussion

Conclusions