(1R,2S,6R)-2-Hydroxymethyl-2,6-dimethyl-3-oxabicyclo[4.2.0]octane, a new volatile released by males of the papaya borer Pseudopiazurus obesus (Col.: Curculionidae).

Sex-specific volatiles produced by males of the papaya beetle Pseudopiazurus obesus are (1R,2S)-grandisal (1), (1R,2S)-grandisol (2), and the new (1R,2S,6R)-2-hydroxymethyl-2,6-dimethyl-3-oxabicyclo[4.2.0]octane (3) termed papayanol.

Identification of sex pheromone components of the hessian fly, Mayetiola destructor.

Coupled gas chromatographic (GC)-electroantennographic detection (EAD) analyses of ovipositor extract of calling Hessian fly, Mayetiola destructor, females revealed that seven compounds elicited responses from male antennae. Four of the compounds-(2S)-tridec-2-yl acetate, (2S,10Z)-10-tridecen-2-yl acetate, (2S,10E)-10-tridecen-2-yl acetate, and (2S,10E)-10-tridecen-2-ol-were identified previously in female extracts. Two new EAD-active compounds, (2S,8Z,10E)-8,10-tridecadien-2-yl acetate and (2S,8E,10E)-8,10-tridecadien-2-yl acetate, were identified by GC-mass spectroscopy (MS) and the use of synthetic reference samples. In a Y-tube bioassay, a five-component blend (1 ng (2S)-tridec-2-yl acetate, 10 ng (2S,10E)-10-tridecen-2-yl acetate, 1 ng (2S,10E)-10-tridecen-2-ol, 1 ng (2S,8Z,10E)-8,10-tridecadien-2-yl acetate, and 1 ng (2S,8E,10E)-8,10-tridecadien-2-yl acetate) was as attractive to male Hessian flies as a similar amount of female extract (with respect to the main compound, (2S,10E)-10-tridecen-2-yl acetate). The five-component blend was more attractive to male flies than a three-component blend lacking the two dienes. Furthermore, the five-component blend was more attractive than a blend with the same compounds but that contained one tenth the concentration of (2S,8E,10E)-8,10-tridecadien-2-yl acetate (more accurately mimicking the ratios found in female extract). This suggests that the ratios emitted by females might deviate from those in gland extracts. In a field-trapping experiment, the five-component blend applied to polyethylene cap dispensers in a 100:10 microg ratio between the main component and each of the other blend components attracted a significant number of male Hessian flies. Also, a small-plot field test demonstrated the attractiveness of the five-component blend to male Hessian flies and suggests that this pheromone blend may be useful for monitoring and predicting Hessian fly outbreaks in agricultural systems.

Enfleurage, lipid recycling and the origin of perfume collection in orchid bees.

Enfleurage, the extraction of elusive floral scents with the help of a lipophilic carrier (grease), is widely used in the perfume industry. Male neotropical orchid bees (Euglossini), which accumulate exogenous fragrances as pheromone analogues, use a similar technique. To collect fragrances, the bees apply large amounts of straight-chain lipids to odoriferous surfaces from their cephalic labial glands, which dissolve the volatiles, and the mixture is then transferred to voluminous hind-leg pockets. Here, we show that males do in fact operate a lipid conveyor belt to accumulate and concentrate their perfume. From the hind-leg pockets of caged male Euglossa viridissima, deuterated derivatives of carrier lipids were consecutively sequestered, shuttled back to the labial glands and reused on consecutive bouts of fragrance collection. Such lipid cycling is instrumental in creating complex perfume bouquets. Furthermore, we found that labial glands of male orchid bees are strikingly similar to those of scent-marking male bumblebees in terms of size, form and structure. This, and a prominent overlap in secretory products, led us to propose that perfume collection evolved from scent-marking in ancestral corbiculate bees.

Identification of the sex pheromone of the swede midge, Contarinia nasturtii.

Coupled gas chromatographic-electroantennographic detection analyses of ovipositor extracts of calling Contarinia nasturtii females revealed two compounds that elicited responses from antennae of male midges. Using synthetic reference samples, these components were identified by gas chromatography mass spectrometry and enantioselective GC as (2S,9S)-diacetoxyundecane and (2S,10S)-diacetoxyundecane. In addition, trace amounts of 2-acetoxyundecane were found in ovipositor extracts, and the (S)-enantiomer was synthesized. When tested in the wind tunnel, a blend of 5 ng (2S,9S)-diacetoxyundecane and 10 ng (2S,10S)-diacetoxyundecane (mimicking the ratio found in the extracts) did not attract any of the males tested, but when 0.1 ng (S)-2-acetoxyundecane was added to the blend, 86.8% of the males were attracted to the bait. Three-component blends with lower or higher relative concentrations than 1% of (S)-2-acetoxyundecane [relative to (2S,10S)-diacetoxyundecane] were less attractive. In a field trapping experiment with released laboratory-reared C. nasturtii adults, traps baited with 500:1000:10 ng of (2S,9S)-diacetoxyundecane/(2S,10S)-diacetoxyundecane/(S)-2-acetoxyundecane applied to rubber septa or dental cotton rolls were tested. Traps without dispensers were used as controls. All three treatments were tested at 20 and 50 cm above ground. The estimated recapture rate was 30-50%, and 81.9% of the recaptured males were caught in traps positioned at 20 cm above ground, and 88.4% in traps with dental cotton rolls as dispensers.