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A model for mate competition in moths sexually signalling with pheromones is presented. The model has four variables. N is the number of individuals of each sex per area unit. r is the length of the female odour plume as detected by a responding male. ε is a parameter increasing with male ability to discriminate between concentrations. r-ε becomes the competitive part of the female pheromone plume

The repeatability of the composition of pheromone emitted by individual female moths (Yponomeuta) was determined by gas Chromatographic analysis. An improved technique for repeated collections of airborne volatiles from the same moth was developed. The procedure did not harm the females and allowed precise quantification of 0.05 ng of pheromone components in 30-min collections. Individual females

The nine sympatric forms of small ermine moths of the genus Yponomeuta (Lepidoptere; Yponomeutidae) in the west palaearctic region show various degrees of differentiation1,2, including among other characteristics, differences in their sexual pheromones3. As is the case for many other moths4, the ermine moths so far analysed use delta 11-unsaturated acetates ((Z)-11-tetradecenyl, (E)-11-tetradeceny

Female pheromone gland extracts from cultures of Agrotis segetum originating from Sweden, France, Hungary and England were analysed for pheromone components and precursors (fatty acids). The pheromone blends were similar in moths from the Swedish, English and Hungarian populations, whereas the French diverged with a much higher amount of (Z)-7-decenyl acetate relative to the homologous pheromone c

(16-D3)palmitic acid was applied topically to pheromone glands of the turnip moth. After incubation omega labeled analogues of fatty acid methyl esters and acetates were identified by gas chromatography with flame ionization detection and selected ion monitoring. The pheromone components (Z)-5-decenyl, (Z)-7-dodecenyl- and (Z)-9-tetradecenyl acetate were all biosynthesized from palmitic acid along

(Z)‐11‐hexadecenyl acetate (Z‐11–16:Ac), (Z)‐11‐hexadecenal (Z‐11–16:Ald), (Z)‐11‐hexadecenol (Z‐11–16:OH) and hexadecanyl acetate (16:Ac) were found in pheromone gland extracts of female Mamestra suasa (Den. et Schiff.) in the relative amounts 100/2/10/5. All four compounds were also present in collections of airborne volatiles from calling females in a 100/7/5/5 ratio. No traces of 14 carbon ald

Reproductive isolation among four sympatric small ermine moths (Yponomeuta) is analyzed in terms of niches in the sexual communication channel. Potential pheromone components were identified from pheromone gland secretions of Y. evonymellus, Y. cagnagellus, Y. padelius, and Y. vigintipunctatus by gas chromatography with flame ionization and electroantennographic detection and tested for behavioral

Chain-elongated analogues of (Z)-dec-5-enyl acetate, a pheromone component of the turnip moth, Agrotis segetum, have been studied. The conformational energies required for the analogues to mimic spatial relationships in the parent molecule, assumed to be crucial for the receptor interaction, were calculated by molecular mechanics (MM2). The calculated energies show a striking correlation with meas

Female pheromone gland extracts of two primitive New Zealand tortricid species that use (Z)-8-tetradecenyl acetate as a pheromone component were analyzed for pheromone precursors. Both Planotortrix excessana and Ctenopseustis obliquana contained (Z)-8-tetradecenoate as well as large amounts of (Z)-10-hexadecenoate. We propose that (Z)-8-tetradecenyl acetate is synthesized from hexadecanoate (palmi

In this paper, the execution and results of an evacuation experiment that was conducted in a road tunnel in Stockholm in 2014 is presented. The primary objective of the experiment was to evaluate the effectiveness of different emergency exit portal designs, and other technical installations/aids in the tunnel, during a fire evacuation in smoke. Based on the results, it is concluded that the emerge

A simple method of widespread applicability in determining double bond positions in C12, C14, and C16 straight-chain monounsaturated acetates is presented. The analysis is made with a capillary gas chromatograph coupled to a low-resolution mass spectrometer which is operated in the electron impact mode. No chemical derlvatlzation of the unknowns is needed. Five pairs of selected mass spectral frag

The evacuation of disabled persons from multi-storey buildings requires, typically, the provision and use o Areas of Refuge (AoR). Building complexity, together with the low level of detail in the regulatory guidance- relating to AoR signage, may lead to inappropriate signage system designs. In turn. this may lead to difficulties in locating and or identifying AoR. This paper illustrates the use o

Female turnip moths (Agrotis segetum) from a laboratory culture inbred for more than 30 generations, and the offspring (first and third generation) from field-collected insects were analyzed individually for acetates and alcohols in the pheromone gland. Quantitative analysis of individual components was performed at the subnanogram level by gas chromatographymass spectrometry (selected ion monitor

The response of individual male turnip moths Agrotis segetum was observed in a sustained flight tunnel to a mixture of decyl acetate, (Z)-5-decenyl acetate, (Z)-7-dodecenyl acetate, and (Z)-9-tetradecenyl acetate in proportions similar to those found in gland extracts from virgin females (0.6: 1:5:2.5). Lures containing 3-30 μg (Z)-5-decenyl acetate proved to be maximally attractive, with approxim