Algaecide Activity of Organic Clay Mineral Modified by Bis-QAC

A new organic clay mineral(O-MMT) was synthesized by using montmorillonite(Na-MMT) and bis-type quaternary ammonium compound, 1,5-(pentamethylene) bis (N,N`-diethyl dodecyl acetate ammonium bromide) [PDA] and its CEC, hydrophobicity and algaecide activities were investigated. Results showed that contact angle of Na-MMT and O-MMT are 45.3° and 138.0°, and their CEC are 1.02 and 1.43 mmol•g-1, respectively. O-MMT had 98.5% average algal survival rate against Microcytis, Anabaena, Chlorella and Chlamydomonas at the optimal algaecide conditions, 48h treatment time and 1.0 g•L-1 dosage, which is far higher than 48% of Na-MMT.

Essential Oils of Boronia megastigma—Selection of Improved Genotypes

Boronia megastigma is cultivated or picked from natural stands in Western Australia for the production of essential oil. Boronia absolute is extracted from the highly perfumed flowers. It is currently valued at between US$4000 and US$7000 per kilogram, and world consumption for perfumery is about 1 tonne. The variation in essential oil composition within and between populations has indicated considerable variation in oil components. Some individuals have high β-ionone and low levels of pinenes. Principle components analysis indicated that the content of β-ionone and dodecyl acetate were tightly linked, as were the monoterpenes, α-pinene, β-pinene, and, to a lesser extent, limonene. Separate linkages between the desirable oil components (β-ionone and dodecyl acetate) and the undesirable components (α-pinene, β-pinene, and limonene) will facilitate selection of plants to be used in oil production.

UTILIZATION OF WESTERN FLOWER THRIPS ALARM PHEROMONE AS A PREY-FINDING KAIROMONE BY PREDATORS

The alarm pheromone of the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is present in the droplet of anal fluid produced by second-instar nymphs when attacked by predators. Because the anal droplet is used in defense against arthropod predators, it was hypothesized that the alarm pheromone (decyl acetate plus dodecyl acetate) acts as a defensive allomone. This hypothesis was refuted by the demonstration that two predators use the pheromone as a prey-finding kairomone. On a leaf arena, Orius tristicolor White (Hemiptera: Anthocoridae) increased its rate of turning in response to the pheromone, and spent 25% of its time within 5 mm of a pheromone source. When given a choice between connected leaf discs containing a pheromone- or solvent-treated wick, Amblyseius cucumeris (Oudemans) (Acarina: Phytoseiidae) spent a greater proportion of time on the pheromone-containing disc, suggesting an arrestment effect.