Filling Voids in Subterranean Termite (Blattodea: Rhinotermitidae) Bait Stations With Soil or Clay Improves Preference and Performance

Abstract

Subterranean termites often transport soil into bait stations. In this study, we hypothesize that adding soil or clay material in the bait may affect preference and performance of termites. Choice and no-choice tests were conducted in the laboratory to investigate the aggregation and feeding preference, survivorship, wood consumption, and body water percentage of termites in response to food containers (here we simulated the bait station by placing a wood block into a bigger plastic box with termite-entering holes on the wall) with the void space filled with soil (sandy clay loam), clay material (sodium bentonite), or remained unfilled. Choice tests showed that under low-moisture conditions, food containers filled with clay attracted significantly more termites (Coptotermes formosanus Shiraki (Blattodea: Rhinotermitidae) and Reticulitermes guangzhouensis Ping (Blattodea: Rhinotermitidae)) compared to food containers filled with soil, or unfilled. Under medium-moisture conditions, however, the percentages of termites that aggregated in the food containers filled with soil or clay were similar, and both were significant higher than the percentages in unfilled ones. In no-choice tests, the highest survivorship and wood consumption in C. formosanus were recorded under medium-moisture conditions and when food containers were filled with clay, whereas the lowest survivorship and wood consumption were recorded under low-moisture conditions and when food containers were filled with soil. Interestingly, presence of clay increased the body water percentage of termites. Our study enhances the understanding of the foraging ecology of subterranean termites, and may contribute to the improvement of termite-baiting technologies.

Super Absorbent Polymers Buried within Dry Soil Attract Formosan Subterranean Termites (Blattodea: Rhinotermitidae)

“…Suran and Rust [22] reported that 3% xylose in the food (paper discs) significantly increased the intake and horizontal transfer of hexaflumuron among individuals of Reticulitermes hesperus Banks, and caused significantly higher termite mortality than that of hexaflumuron alone. Other reported termite attractants include wood-rotting and soil fungi [23][24][25][26][27], decayed wood extract [28], carbon dioxide [29,30], clay materials [11,31,32], and even some sport drinks [33].…”

“…Under wet conditions, significantly more termites were found in the baiting containers filled with soil and consumed more wood compared with baiting containers filled with super absorbent polymers or which remained unfilled. In the field, termites usually transport soil or clay into the hollow spaces of trees and bait stations [11,37]. Li and Su [38] claimed that such behaviors help termites to transform the void spaces to "tunnel space during soil displacement".…”

“…Three colony groups of C. formosanus (>500 m apart from each other) were collected in the campus and arboretum of South China Agricultural University (SCAU), Guangzhou, China, using underground monitoring stations containing pine wood sticks [11]. The monitoring stations infested by C. formosanus were brought to the laboratory and maintained in 60 L plastic containers for <1 month.…”

“…Few studies tried to increase the moisture conditions of bait matrices or soil around bait stations and therefore improve bait attractiveness to termites. For example, Xiong et al [11] reported that filling the void volume of bait stations with sodium bentonite, a clay material with the ability to absorb and retain large amounts of water, can significantly increase wood moisture and bait consumption by termites under dry conditions. However, filling the bait stations with another water-retaining material, polyacrylamide/attapulgite composite, showed no promise to increase wood consumption by termites [12].…”

Effects of clay materials and moisture levels on habitat preference and survivorship of Formosan subterranean termite,Coptotermes formosanusShiraki (Blattodea: Rhinotermitidae)

“…Also, termites preferentially used clay to cover the smooth surface of containers and construct shelter tubes (Wang & Henderson, 2014;Wang, Henderson & Gautam, 2015). Xiong et al (2018a) reported that significantly more C. formosanus and Reticulitermes guangzhouensis Ping aggregated and fed in baiting containers filled with bentonite, a clay mineral, than unfilled containers. In each of these studies, preference of termites to a single source of clay material was investigated and confirmed, but two questions remained unanswered: (1) Do clay types and moisture conditions influence the aggregation and feeding preference by termites?…”