Subterranean termites encounter numerous kinds of fungi during foraging and feeding activities. Nearly nine decades of research have exposed only a small fraction of the termitefungal interactions that exist in nature. The first portion of research presented here focused on how feeding behaviors of Reticulitermes virginicus (Banks) were affected by the fungus Trichoderma virens (Miller, Giddens & Foster) von Arx. Tests were performed with 'P' (GLT+) and 'Q'(GLT-) strains of T. virens. Both strains were applied to filter paper and wood disks cut from southern yellow pine and Sentricon® monitoring devices. The first bioassay assessed the termites' feeding responses to fungal extracts removed from liquid media on days 2 through 7, and again on day 15. Only the GLT+ extracts from days 6 and 7 inhibited termite feeding significantly from the controls (16% and 54% less area loss, respectively). Response to wood covered by live T. virens mycelia was tested in the second bioassay. No significant differences in termite consumption were seen between fungal strains, but both substantially reduced the area loss due to termite feeding of treated wood by an average of 35%. A vacuum impregnation system was used to inoculate wood disks with fungal homogenate in the third bioassay. The wood treated with either GLT+ or GLT- homogenates did not have significant differences in area loss due to termite feeding. Overall, these results reiterated the plasticity that exists with termitefungal relationships. The second research topic addressed the applicability of labrum-based identification techniques to Reticulitermes Holmgren in Texas. Soldier labral morphology of four species, R. flavipes (Kollar), R. hageni (Banks), R. tibialis Banks, and R. virginicus (Banks), was evaluated as a character to separate species. Length and width measurements of five soldier labra were taken from each of the eight collection sites. These results were then judged against molecular analysis of the mtDNA 16S rRNA gene. Findings showed that labral shape was an unreliable diagnostic characteristic when comparing all species. A combination of length and length-towidth ratio successfully segregated all four Reticulitermes species. Comparison of a morphology-based dendogram to the phylogenetic analysis revealed a shared pattern between phenotypic and genotypic variations.

Memoria para optar al Título Profesional de Ingeniero Forestal / Se determinó la preferencia alimenticia mostrada por la termita subterránea Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae), frente a diez especies de madera, mediante ensayos de laboratorio y de campo en la Región Metropolitana de Santiago, Chile. Las especies ensayadas fueron ocho latifoliadas y dos coníferas, entre las que se incluyeron pino radiata y eucalipto, dos importantes especies introducidas en el país. El tamaño de las probetas y procedimientos de manejo de las colonias de termitas, evaluación de grado de ataque, y otros aspectos se basaron en lo señalado en la Norma Chilena NCh 3060 (2007). En laboratorio se realizaron tres repeticiones con 10 probetas de cada una de las especies utilizadas, y en terreno se instalaron dos micropruebas de campo, en localidades distintas, con el uso de 100 probetas en cada sitio ensayado. Se consideró el empleo de maderas comerciales de amplio uso y de maderas con distintas propiedades físicas, anatómicas, químicas y de durabilidad natural. La evaluación de las probetas se hizo cuatro meses después de instalado el ensayo de laboratorio y tres a cinco meses en campo.

Commercial termite baiting systems were utilized and evaluated under real-world conditions in order to provide a comparison of efficacy in the management of subterranean termites. Three commercial termite baiting systems available for comparison included: FirstLine® (FMC Corp.), Sentricon® (Dow AgroSciences), and Terminate® (United Industries, Inc). The time required for foraging termites to locate and begin feeding on both the Sentricon® and the Terminate® bait stations was approximately one-half the time required to locate and begin feeding on the FirstLine® system, for both R. flavipes and C. formosanus. The time required for C. formosanus to locate and begin feeding on all termite baiting systems was approximately one-half the time required for R. flavipes. There were no significant differences in efficacy between the three baiting treatment systems against R. flavipes, with a mean of 84% efficacy for all systems. The Sentricon® system was able to achieve efficacy (88%) results with few additional residual liquid termiticide treatments. FirstLine® efficacy (80%) and Terminate® efficacy (84%) results required initial and subsequent multiple spot treatments with residual termiticide for comparable results. The Sentricon® baiting system yielded positive results in the management of C. formosanus, if utilized in an aggressive, active management program, involving multiple supplementary in-ground and above-ground bait stations at both points of active infestation and at areas with conditions conducive to infestation. Optimum results were achieved when monitoring of the bait stations occurred twice each month, rather than the standard monthly monitoring regime. The two termite baiting systems with Sulfluramid as the active ingredient required spot treatments with termiticides in order to protect the structures. Grids of bait stations were installed and termite activity and foraging strategies were monitored for a five-year period. Treatment with sulfluramid required 472 active ingredient tubes, over a 37-month period, in order to reduce subterranean termite populations. Observations of seasonal variation and spatial patterns of foraging by native subterranean termites, R. flavipes, in a typical urban/suburban setting provided information with direct application to an effective termite baiting system program.

Commercial termite baiting systems were utilized and evaluated under real-world conditions in order to provide a comparison of efficacy in the management of subterranean termites. Three commercial termite baiting systems available for comparison included: FirstLine® (FMC Corp.), Sentricon® (Dow AgroSciences), and Terminate® (United Industries, Inc). The time required for foraging termites to locate and begin feeding on both the Sentricon® and the Terminate® bait stations was approximately one-half the time required to locate and begin feeding on the FirstLine® system, for both R. flavipes and C. formosanus. The time required for C. formosanus to locate and begin feeding on all termite baiting systems was approximately one-half the time required for R. flavipes. There were no significant differences in efficacy between the three baiting treatment systems against R. flavipes, with a mean of 84% efficacy for all systems. The Sentricon® system was able to achieve efficacy (88%) results with few additional residual liquid termiticide treatments. FirstLine® efficacy (80%) and Terminate® efficacy (84%) results required initial and subsequent multiple spot treatments with residual termiticide for comparable results. The Sentricon® baiting system yielded positive results in the management of C. formosanus, if utilized in an aggressive, active management program, involving multiple supplementary in-ground and above-ground bait stations at both points of active infestation and at areas with conditions conducive to infestation. Optimum results were achieved when monitoring of the bait stations occurred twice each month, rather than the standard monthly monitoring regime. The two termite baiting systems with Sulfluramid as the active ingredient required spot treatments with termiticides in order to protect the structures. Grids of bait stations were installed and termite activity and foraging strategies were monitored for a five-year period. Treatment with sulfluramid required 472 active ingredient tubes, over a 37-month period, in order to reduce subterranean termite populations. Observations of seasonal variation and spatial patterns of foraging by native subterranean termites, R. flavipes, in a typical urban/suburban setting provided information with direct application to an effective termite baiting system program.

Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención: Sanidad Vegetal

Recent and anticipated global change has focused concern on the role of forests in ecosystem functioning and carbon sequestration. Of key importance is identifying relevant factors that drive carbon and nutrient dynamics and the consequences of changes in these processes. Systems undergoing invasion by invasive woody species are particularly prone to changes. This study examined the branch and crown biomass and decay dynamics for the invasive Chinese tallow tree in Mississippi, USA as well as the influences of stand and site conditions on biomass modeling and arthropod contributions to fine woody debris decay. Coupling biomass and decay models presents a method for modeling carbon sequestration and nutrient turnover rates at the stand level. These predictions will aid our understanding of the consequences of ecosystem change, especially those driven by invasive species.

The overall aim of this study was to investigate the potential influence of chitosan, a biodegradable and antimicrobial compound, on termite hindgut symbionts. For this purpose, a morphological quantifying technique was conducted on the protist community’s hindgut after feeding termites on chitosan-treated wood. The aim was to characterize the diversity of protist species in the economically important dark southern subterranean termite, Reticulitermes virginicus. A molecular phylogenetic analysis of the V3 and V4 hyper-variable regions of 16S ribosomal RNA (rRNA) gene of the bacterial community in the hindgut of R. virginicus was performed on termites exposed to chitosan treatment. Light microscopy visualization of protist species residing in the hindgut of workers showed presence of ten protist species both in the control sample and in termites fed a low concentration of chitosan. In this study, the coexistence of two species of the genus Trichonympha (T. agilis and T. burlesquei) is reported for the first time in R. virginicus. Monocercomonas sp. and Trichomitus trypanoides were the only two protists found in termites exposed to wood treated with higher chitosan concentration solutions and the absence of wood fragments in their food vacuoles was clear. This feature indicates that these two protists may not be involved in the digestion of the wood fragments impregnated with chitosan. The results of this study indicated that the potential effect of chitosan caused elimination of the protist species in termite hindguts. The genomic DNA of bacterial hindgut community of R. virginicus were profiled using sequences which amplified theV3-V4 sub-regions of 16S rRNA gene. Sequences were analyzed using a taxonomic analysis tool, Quantitative Insights Into Microbial Ecology (OIIME 2), in order to infer the effect of chitosan on the composition of the bacterial fauna in the hindgut. The richness and evenness results indicated that the most diversity was observed in the bacteria from termites not being exposed (UNX) to treatment compared to other treatment groups. On the other hand, the lowest richness and evenness were determined for chitosan-treated wood (CTE) and starved termites (STV). Of 28 bacterial phyla, Bacteroidetes, Firmicutes, Elusimicrobia, and Proteobacteria were the most dominant phyla across all the treatment groups. The results suggest that chitosan treated wood led to the microbial community shifts in R. virginicus. In addition, lack of a nutrition source and other changes in termite’s food affect the termite hindgut bacterial diversity.

This dissertation defines electromagnetic properties that are responsible for directing subterranean termite foraging behavior. Research identified specific frequencies and intensities that can attract Coptotermes formosanus Shiraiki and Reticulitermes flavipes (Kollar) to the site where the electrical fields are generated and defined on repellant freuency and intensity for C. formosanus. US Patent Docket Number 2343-215 PCT and MSU disclosure 05-0606-163 were filed based on the results. Data showed that frequencies and intensities were different for attracting the two species. Future work will address new alternatives for addressing termite infestations that will reduce and change the amounts and use of current termiticides.

No description available.

This research focuses on the evaluation of many aspects of the American Wood Protection Association (AWPA) Standard E1-97, “Standard Method for Laboratory Evaluation to Determine Resistance to Subterranean Termites.” This standard is used extensively for testing the efficacy of new products and preservative systems against subterranean termite species. Research was done to determine what changes, if any, are needed for testing against subterranean termite species such as Coptotermes formosanus (Shiraki) and species of native termite genus Reticulitermes (Holmgren), primarily R. flavipes (Kollar). Variables from the current standard were tested to determine effects of parameters such as moisture of sand substrate; size, type, and location of test material within a test bottle; and termite number and ratios of workers to soldiers per test bottle. Research also improved comprehension of termite biology in a laboratory setting, enabling researchers to develop new and safer control methods.