Posted on: 02 March, 2017
Author: Alexander P
The evidence is increasing in support of Wright’s (1964) prediction that most insects use more than one attractant chemical. Pressures from sympatric upeciu. which utilize a common attractant, c... The evidence is increasing in support of Wright’s (1964) prediction that most insects use more than one attractant chemical. Pressures from sympatric upeciu. which utilize a common attractant, could contribute to the importance placed on secondary chemicals as a means of reducing communication interference. Con- tinued selection could result in the evolution of a pheromone system in which the secondary chemical becomes the main component and the original attt cunt chemical is used as a minor chemical or not at all. An example of species pol ibly If different stages in this sort of model is that of Adoxophyes orana Fischer Von Réislerstamm and Clepsis spectrana (Treitschke). Aphrodisiac is a popular term loosely applied to many pheromones which are thought to play an important role in the successful achievement of copulation through their use in courtship behavior. The standard pheromone model for bring- ing sexual partners together is that one sex, usually the female, releases a pheromo- ne into the atmosphere often only under prescribed environmental and physiologi- cal conditions (Shorey ch. 4). The opposite sex, usually male, is stimulated by this pheromone to approach the source. At close range, other stimuli (visual, auditory or tactile) alone or in conjunction with the pheromone may stimulate him to continue courtship and to copulate. The higher concentration of the female sex pheromone near the source may be enough on its own to release courtship and copulatory behavior (sect. 7.2) and, in that case, would be utilized as both an at- tractant and a courtship or copulatory pheromone in the two different contexts. However, other pheromones may be released specically during courtship and at no other time. Examples are the pheromones disseminated by the hairpencils of danai- ine butteries during courtship ight which induce the female to alight (sect. 7.4.1) or the male cockroach secretion (sect. 7.3) which induces the female to mount the male and thus attain the correct copulatory stance. The term aphrodisiac pheromone has become widely used since Butler (l967a) introduced it into the current literature on pheromones and defined it as a ‘sub- stance produced by one or other sex, usually by the male and often as only a part of a complex pattern of courtship behavior, preparing the opposite sex for copula- tion after the pair has been brought together by olfactory sex attractants and other means’. The emphasis is mine since it clearly differentiates between sex pheromones that act as aphrodisiacs and those that attract the opposite sex over a distance. Mate- rials which may act as aphrodisiacs by inducing courtship or other sexual behavior, but which come from the environment (e.g. Riddiford 1967) are eliminated from our discussion since they are not pheromones. Shorey (1973) has recently taken up the term aphrodisiac, but with reservations. He contends that a true aphrodisiac should be known according to http://mpommett.blog.fc2.com/blog-entry-5.html They directly affect that part of the nervous system in the female that controls her mating behavior, increasing the chance that she will accept the male in copulation (it could equally well be a female to male effect), whereas many of the pheromones described as aphrodisiacs exert their effect on other parts of the nervous system, such as inhibiting ight or stimulating feeding behavior. Such criticism, however, appears to be somewhat teleological in attempting to avoid the rigor of behavioral experiment and critical observation by cloaking it with terminology. Nor is the neurophysiological basis for behavior well enough defined to know, morphologically or neurologically, what part of the nervous system, if it is a specific part, controls mating behavior. It is also easy to confuse the function of a behavior pattern with its mechanism. The mechanisms of behavior involved in feeding or in the inhibition of locomotion may be involved in an identical way as part of food searching, escape from predation or sexual behavior, but this in no way lessens their function in releasing specific parts of precopulatory behavior and directly promoting successful copulation, even if this is not clear at first glance. Source: Free Articles from ArticlesFactory.com Alexander P is a blogger from Los Angeles that studies human pheromones.