Trail and recruitment pheromones in Camponotus socius (Hymenoptera: Formicidae)

Summary. Worker ants of Camponotus socius employ multicomponent signals during group recruitment to food sources and nest emigrations. The chemical signals consist of trail orientation pheromones that originate from the hindgut. Two components that elicit trail orientation behavior were identified: (2S,4R,5S)-2,4-dimethyl-5-hexanolide and 2,3-dihydro-3,5-dihydroxy-6-methylpyran-4-one. Although both compounds release trail following behavior, in choice tests the former compound is preferred significantly. The major recruitment signal appears to be formic acid discharged from the poison gland. Compounds identified in the Dufour gland secretions do not seem to be involved in the recruitment process.     

Prodigiosin metabolites of a marine Pseudomonas species

The major pigment of a marine micro-organism was identified as prodigiosin on the basis of analytical and spectral data. Two minor pigments were tentatively assigned structures, from thin-layer chromatography (TLC) and mass spectral data, as prodigiosin homologs with 3-n-hexyl and 3-n-heptyl side-chains. The micro-organism was classified as a new Pseudomonas species on the basis of its morphological and biochemical characteristics. It was named Pseudomonas magnesiorubra (ATCC No. 21856).     

A trail pheromone component of the ant Mayriella overbecki Viehmeyer (Formicidae: Myrmicinae)

 The myrmicine ant Mayriella overbecki lays recruitment trails during foraging and nest emigrations. The trail pheromone originates from the poison gland. From ten identified components of the poison gland secretions only methyl 6-methylsalicylate 1 elicited trail following behavior. Received: 6 April 2000 / Accepted in revised form: 6 June 2000     

Source profiles for industrial, mobile, and area sources in the Big Bend Regional Aerosol Visibility and Observational study

Representative PM2.5 and PM10 source emissions were sampled in Texas during the Big Bend Regional Aerosol Visibility and Observa (BRAVO) study. Chemical source profiles for elements, ions, and carbon fractions of 145 samples are reported for paved and unpaved road dust, soil dust, motor vehicle exhaust, vegetative burning, four coal-fired power stations, an oil refinery catalytic cracker, two cement kilns, and residential meat cooking. Several samples were taken from each emitter and source type, and these were averaged by source type, and in source subgroups based on commonality of chemical composition. The standard deviation represents the variability of the chemical mass fractions. BRAVO profiles differed in some respects from profiles measured elsewhere. High calcium abundances in geological dust, high selenium abundances in coal-fired power stations, and high antimony abundances in oil refinery catalytic cracker emissions were found. Abundances of eight thermally evolved carbon fractions [Atmos. Environ. 28 (15) (1994) 2493] differ among combustion sources, and a Monte Carlo simulation demonstrates that these differences are sufficient to differentiate among several carbon-emitters.