Wood Preference of Reticulitermes virginicus (Blattodea: Rhinotermitidae) Using No-, Two-, and Four-Choice Designs and Seven Different Measures of Wood Consumption.

Three hundred Reticulitermes virginicus (Banks) workers were exposed to three 1-cm3 wood blocks of either Quercus sp. (Red Oak), Populus sp. (Poplar), Pinus sp. (Pine), or Sequoia sp. (Redwood) placed into one of the three bioassay designs (no-, two-, and four-choice) for 21 d. Termite wood consumption was measured by wood weight loss, resistance class, and visual rating. Wood consumption rates were determined using four formulas in addition to two standardized visual rating scales (American Society for Testing and Materials [ASTM] and American Wood Protection Association [AWPA]) and a preference ranking obtained for each measure. The wood consumption formula, rating scale, and preference rankings were compared by bioassay design. The overall preference ranking of the four wood types as determined by the combination of all three designs was­1) Pine, 2) Red Oak, 3) Redwood, and 4) Poplar. Results indicate that bioassay design influenced both wood consumption and preference rankings. A no-choice design can determine aversion; a four-choice design the most preferred wood; and a two-choice design can illuminate the fine details of comparative preference. The different formulas employed for calculation of consumption rate influenced preference ranking in the no- and four-choice designs but not the two-choice design.

Impact of five commercial baits containing chitin synthesis inhibitors on the protist community in Reticulitermes flavipes (Isoptera: Rhinotermitidae).

Eastern subterranean termite, Reticulitermes flavipes (Kollar), workers were continuously exposed to one of five chitin synthesis inhibiting (CSI) active ingredients and the protist community from the hindgut quantified biweekly for 21 d. The CSIs tested included commercially available formulations of diflubenzuron, hexaflumuron, lufenuron, noviflumuron, and novaluron. Results showed termites exposed to CSIs had a significant decrease (>or=30%) in the estimated total protist population after 3 d, regardless of treatment. Protist species impacted were Dinenympha fimbriata, D. gracilis, Microjoenia fallax, Pyrsonympha vertens, and Trichonympha agilis and could be indicative of weakened digestive homeostasis, but further studies are needed. We also provide evidence that lufenuron is highly toxic and discuss some of the implications this might have on termite management practices.

Correspondence of soldier defense secretion mixtures with cuticular hydrocarbon phenotypes for chemotaxonomy of the termite genus Reticulitermes in North America.

Soldier defense secretions from samples of Reticulitermes collected in California, Nevada, Arizona, New Mexico, and Georgia were characterized and correlated with cuticular hydrocarbon phenotypes. Twenty-seven cuticular hydrocarbon phenotypes have been defined, and soldier defense secretion (SDS) phenotypes have been described for 25 of these. Forty-five terpenoid compounds were found, including monoterpenes, sesquiterpenes, and a few diterpenes. The monoterpenes include (-)-alpha-pinene, (-)-beta-pinene, (-)-camphene, myrcene, (Z)- and (E)-ocimene, and (-)-limonene. The major sesquiterpenes produced are (+)-gamma-cadinene, (+)-gamma-cadinene aldehyde, (-)-germacrene A, germacrene B, gamma-himachalene, and beta-bisabolene. Some SDS phenotypes pair with more than one cuticular hydrocarbon phenotype; however, with two exceptions, each hydrocarbon phenotype is associated with only one SDS phenotype. These chemical characterizations lend support to the conclusion that there are numerous undescribed species of Reticulitermes in North America.

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.