Thermal signatures of human pheromones in sexual and reproductive behaviour

Chemically mediated sexual communication in humans has been largely neglected due to its non-conscious and relatively concealed nature. However, menstrual cycle synchronisation, puberty onset in young pre-pubertal girls exposed to their stepfather, and consanguinity avoidance suggest a function in the physiological regulation of sexual and reproductive behaviour in humans. These phenomena are related to activation of the limbic system by pheromones. On the basis of sexually dimorphic activation of brain hypothalamic areas and the control of body temperature via the hypothalamus, our hypothesis is that human sexual pheromones can induce thermal effects that can be revealed by high-resolution thermal infrared imaging. Here we show that in women, male sexual pheromones induce thermal effects that are linked to the ovarian cycle. These findings suggest a dramatic influence of pheromones on human sexual and reproductive behaviour through neuroendocrine brain control, established on the plesiomorphic nature of chemical communication across species

Simultaneously hermaphroditic shrimp use lipophilic cuticular hydrocarbons as contact sex pheromones

Successful mating is essentially a consequence of making the right choices at the correct time. Animals use specific strategies to gain information about a potential mate, which is then applied to decision-making processes. Amongst the many informative signals, odor cues such as sex pheromones play important ecological roles in coordinating mating behavior, enabling mate and kin recognition, qualifying mate choice, and preventing gene exchange among individuals from different populations and species. Despite overwhelming behavioral evidence, the chemical identity of most cues used in aquatic organisms remains unknown and their impact and omnipresence have not been fully recognized. In many crustaceans, including lobsters and shrimps, reproduction happens through a cascade of events ranging from initial attraction to formation of a mating pair eventually leading to mating. We examined the hypothesis that contact pheromones on the female body surface of the hermaphroditic shrimp Lysmata boggessi are of lipophilic nature, and resemble insect cuticular hydrocarbon contact cues. Via chemical analyses and behavioural assays, we show that newly molted euhermaphrodite-phase shrimp contain a bouquet of odor compounds. Of these, (Z)-9-octadecenamide is the key odor with hexadecanamide and methyl linoleate enhancing the bioactivity of the pheromone blend. Our results show that in aquatic systems lipophilic, cuticular hydrocarbon contact sex pheromones exist; this raises questions on how hydrocarbon contact signals evolved and how widespread these are in the marine environment

A male-produced aggregation-sex pheromone of the beetle Arhopalus rusticus (Coleoptera: Cerambycidae, Spondylinae) may be useful in managing this invasive species.

The longhorned beetle Arhopalus rusticus (Coleoptera: Cerambycidae, Spondylinae) is a common species in conifer forests of the Northern Hemisphere, but with global trade, it has invaded and become established in New Zealand, Australia, and South America. Arhopalus rusticus is a suspected vector of the phytopathogenic nematode, Bursaphelenchus xylophilus, the causative agent of pine wilt disease, which is a major threat to pine forests worldwide. Here, we report the identification of a volatile, male-produced aggregation-sex pheromone for this species. Headspace odours from males contained a major male-specific compound, identified as (2 S, 5E)-6,10-dimethyl-5,9-undecadien-2-ol (common name (S)-fuscumol), and a minor component (E)-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone). Both compounds are known pheromone components for species in the same subfamily. In field trials in its native range in Slovenia, (S)-fuscumol was significantly more attractive to beetles of both sexes, than racemic fuscumol and a blend of host plant volatiles commonly used as an attractant for this species. Fuscumol-baited traps also caught significant numbers of another spondylidine species, Spondylis buprestoides (L.), and a rare click beetle, Stenagostus rufus (De Geer). The pheromone can be exploited as a cost-effective and environmentally safe tool for detection and monitoring of this invasive species at ports of entry, and for monitoring the beetle's distribution and population trends in both endemic and invasive populations

Odour perception in the codling moth Cydia pomonella L.

The codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae) is a renowned pest in apple, pear and walnut orchards, and its activities are in large guided by volatile odours as sensory cues. This thesis spans over a large part of the olfactory chain of events in the codling moth, from brain to behaviour. The main emphasis was placed on the detection of plant odours, and some of the works presented are novel to codling moth research. The volatiles emitted by host-plant species were analysed, revealing variations in the odour profiles both between species of host plants and at different phenological stages of a host plant, which indicates that females are flexible in their behavioural response to host odours. A first step was taken to map the antennal olfactory receptor neurons and their specificity, where several behaviourally active compounds were found to be detected by neurons housed in sensilla auricillica, one of the morphological types of sensilla found on the antenna of the moth. In a study of the antennal lobe, the primary integration centre for odour processing in the insect brain, we describe the three dimensional structure of the array of olfactory glomeruli of both sexes. Behavioural experiments show that both males and females are attracted to plant odours, and that host recognition in codling moths are encoded not by single compounds but by a blend of volatiles. Taken together, the results presented in this thesis provide new insights into moth olfaction and odour-dependent behaviour in general, and into that of the codling moth in particular

Different goals in multiscale simulations and how to reach them

In this paper we sum up our works on multiscale programs, mainly simulations. We first start with describing what multiscaling is about, how it helps perceiving signal from a background noise in a ?ow of data for example, for a direct perception by a user or for a further use by another program. We then give three examples of multiscale techniques we used in the past, maintaining a summary, using an environmental marker introducing an history in the data and finally using a knowledge on the behavior of the different scales to really handle them at the same time

The taste of togetherness.

The larvae of fruit flies produce pheromones to control whether they are attracted to others of the same species or whether they avoid members of a different species

A continuous model of ant foraging with pheromones and trail formation

We propose and numerically analyze a PDE model of ant foraging behavior. Ant foraging is a prime example of individuals following simple behavioral rules based on local information producing complex, organized and ``intelligent'' strategies at the population level. One of its main aspects is the widespread use of pheromones, which are chemical compounds laid by the ants used to attract other ants to a food source. In this work, we consider a continuous description of a population of ants and simulate numerically the foraging behavior using a system of PDEs of chemotaxis type. We show that, numerically, this system accurately reproduces observed foraging behavior, such as trail formation and efficient removal of food sources.Comment: Conference proceeding

Bacteria as Ovipositional Attractants for \u3ci\u3eCulex Pipiens\u3c/i\u3e (Diptera: Culicidae)

(excerpt) The study of factors and mechanisms involving ovipositional attractants in mosquitoes is still a relatively new area of research. Some early workers in mosquito biology suggested that gravid mosquitoes simply scattered their eggs indiscriminately on available aquatic sites; however, numerous field studies have failed to provide any real evidence for indiscriminate oviposition. The current idea is that oviposition involves not only locating an aquatic site, but the selection of an environment containing the necessary physical, chemical, and biotic factors required for larval development. It is desirable for female mosquitoes to be able to detect a breeding site that can successfully provide an environment suitable for development of their own species. According to Kramer and Mulla (1979), it is most likely that gravid females of different species use different factors in cueing in on and selecting ovipositional sites