Survey of metabolic reserves, stored uric acid, and water content from field populations of subterranean termites (Isoptera: Rhinotermitidae) from Georgia

Total levels of uric acid, soluble proteins, lipid, glycogen, and body water were determined for Reticulitermes flavipes (Kollar) workers 24-72 h after field collection. In addition, levels of biological molecules were compared for termites collected from the same inspection ports within 24 h after field collection, and after laboratory captivity of 6 or 9 mo. Uric acid content, described in a previous study as steadily accumulating in R. flavipes termites in captivity, was found to be low or undetectable in workers tested after 6 or 9 mo in the laboratory.     

Evaluation of novel and traditional measures for vigor of laboratory-cultured termites, Reticulitermes flavipes (Kollar)

The current study was undertaken to consider predictive methods for describing the vigor of Reticulitermes flavipes (Kollar) termites stored in a laboratory under conditions similar to control groups in bioassay. These novel methods were based on measurements for levels of biological molecules (uric acid, soluble proteins, lipid, and glycogen), percent water content, live weight, and running speed. Also considered were two established, non-predictive methods for determining vigor, survivorship and consumption rate. Of the novel measures tested, lipid and body water percentage show promise in distinguishing weak from vigorous groups of termites, with body water percentage a more practical means of measurement. Low body water percentage was concluded to be an indicator of weak groups of termites.     

DNA technology,interstate commerce,and the likely origin of formosan subterranean termite (Isoptera: Rhinotermitidae) infestation in Atlanta,Georgia

This study was the first to use DNA sequencing data to infer the origin of a Formosan subterranean termite, Coptotermes formosanus Shiraki, infestation. Cytochrome oxidase II gene sequence was used to define eight specific maternal lineages from 14 geographic locations across the southeastern United States, Hawaii, and China. One maternal lineage, A, was unique to all the Atlanta collections and one New Orleans collection, which indicated that termites at these sites shared a common maternal ancestor. The impact of interstate commerce in terms of Formosan subterranean termite introductions is addressed as is the industry response needed to arrest the spread of these termites via commercial traffic in used railroad cross ties.     

Phylogenetic analyses of two mitochondrial genes and one nuclear intron region illuminate European subterranean termite (Isoptera: Rhinotermitidae) gene flow, taxonomy, and introduction dynamics

Phylogenetic analyses of multiple DNA sequences were conducted to elucidate gene flow, evolutionary patterns, taxonomy, and the dynamics of two accidental introductions: Reticulitermes lucifugus grassei into Devon, United Kingdom and R. flavipes into Europe. Two mitochondrial DNA genes totaling 1495 bp and a 380-bp ribosomal intergenic transcribed spacer were sequenced. Neighbor-joining and parsimony analyses revealed that multiple female lineages of R. lucifugus grassei were introduced into Devon possibly from southwestern France, where the species was indigenous. The taxonomic status of the European R. santonensis as a species separate from the North American R. flavipes has been questioned since it was described in 1924. Phylogenetic analyses revealed a close genetic relationship between R. flavipes from the United States and R. santonensis from France. These analyses, coupled with morphological and chemotaxonomic data, provide strong support for R. santonensis and R. flavipes being the same species. They also suggested that R. santonensis infestations likely resulted from R. flavipes being introduced into Europe.     

Repellent effects of isoborneol on subterranean termites (Isoptera: Rhinotermitidae) in soils of different composition

The repellence of the plant-derived bicyclic monoterpenoid isoborneol on subterranean termites was assessed in short-term laboratory bioassays. Depending on concentration, application of isoborneol to different soil types was efficient in creating repellent soil barriers, which were not penetrated by workers of Reticulitermes santonensis De Feytaud or R. flavipes Kollar within 2 wk after adding the substance to the substrate. Isoborneol-treated barriers did not affect termite survival. The bioavailability of the active ingredient decreased with increasing clay content of the soil. Evaporation of isoborneol from treated soil increased with increasing particle size of the substrate and could be reduced by covering the soil surface.     

Cuticular hydrocarbons suggest three lineages in Reticulitermes (Isoptera: Rhinotermitidae) from North America

Cuticular hydrocarbon mixtures can be used to discriminate insect taxa. They have utility for determining phylogenetic relationships where they are independent characters with discrete states and represent a hierarchical distribution of shared, derived characters. We report inferred degrees of relatedness among the chemical phenotypes of Reticulitermes from PAUP (phylogenetic analysis using parsimony) analyses of cuticular hydrocarbon characters. One hundred and forty-one Reticulitermes colonies collected from California, Georgia, New Mexico, Arizona and Nevada were used. Initial maximum parsimony analyses sorted the 141 colonies into 26 chemical phenotypes. Subsequent analyses, using the ancestral species Coptotermes formosanus and Heterotermes sp. as outgroups, sorted Reticulitermes taxa into three major lineages, each characterized by a different set of dominant methyl-branched or unsaturated hydrocarbon components. Reticulitermes in lineage I have cuticular hydrocarbon mixtures with a preponderance of internally branched monomethylalkanes and 11,15-dimethylalkanes. Those in lineage II are defined by a preponderance of 5-methylalkanes and 5,17-dimethylalkanes. Taxa in lineage III are characterized by the predominance of olefins and a relative paucity of n-alkanes and methyl-branched alkanes. Bootstrap analyses and decay indices provided statistical support and robustness for these chemical-based relationships.