Posted on: 02 March, 2017
Author: Alexander P
The analysis of variation in pheromone systems within and between populations of the same species would constitute a considerable contribution to the understanding of the role of pheromones in reprodu... The analysis of variation in pheromone systems within and between populations of the same species would constitute a considerable contribution to the understanding of the role of pheromones in reproductive isolation. Breeding experiments which test the assortment of different types of pheromones and receptors could be especially useful. The hypothesis presented in this article that differences in pheromone systems of closely related species may result from disruptive selection could be...
Posted on: 02 March, 2017
Author: Alexander P
In another experiment, Boch and Morse (1979) divided a colony by a double screen partition and gave each half a queen. Although the top pheromone odours could freely pass though the screen each half w... In another experiment, Boch and Morse (1979) divided a colony by a double screen partition and gave each half a queen. Although the top pheromone odours could freely pass though the screen each half was able to recognize its own - queen when tested several days later, indicating that the queens had not acquired a similar pheromone odour. Therefore, adsorption of odour onto the body...
Posted on: 02 March, 2017
Author: Alexander P
It is obvious that many species could achieve reproductive isolation because they employ different pheromone compounds. In the Tortricidae (table 6.1), structural vuriution, as known to date, is obtai... It is obvious that many species could achieve reproductive isolation because they employ different pheromone compounds. In the Tortricidae (table 6.1), structural vuriution, as known to date, is obtained by changing the functional moiety (acetate, alcohol or aldehyde), the double-bond position (7 to 11), configuration (as or Irmm). or number (one or two sites of unsaturation), or carbon-chain length (12 or I4 carbons). Most of the known lepidopterous attractants in other...
Posted on: 02 March, 2017
Author: Alexander P
Perhaps the male marking pheromone acts as an attractant and arrestant for the queen, but this has yet to be demonstrated experimentally. Perhaps it also acts as an aphrodisiac. The bioassay, mentione... Perhaps the male marking pheromone acts as an attractant and arrestant for the queen, but this has yet to be demonstrated experimentally. Perhaps it also acts as an aphrodisiac. The bioassay, mentioned above, to test the reactions of males to components of site marking pheromones could also be used to test their attractiveness to virgin queens. Queens must seek out the type of location where ight routes of...
Posted on: 02 March, 2017
Author: Alexander P
Learn about the best aggregation pheromone. For example, frass expelled from the galleries, and male paraconfusus guts lose attraction in proportion to the number of females in the gallery, with attra... Learn about the best aggregation pheromone. For example, frass expelled from the galleries, and male paraconfusus guts lose attraction in proportion to the number of females in the gallery, with attraction being completely lost after three or four females are present (Borden 1967). In support of this result, Vité et al. (1972) found that male I. calligraphus joined by three or more females quickly cease to synthesize the frass...
Posted on: 02 March, 2017
Author: Alexander P
There is little evidence for these pheromones. Indeed, under natural conditions the Nasonov pheromone is effective as an attractant in several different behavioural contexts (i.e. when clustering, at ... There is little evidence for these pheromones. Indeed, under natural conditions the Nasonov pheromone is effective as an attractant in several different behavioural contexts (i.e. when clustering, at the hive entrance, at a source of water) but in each of these situations the nerol and farnesol components appear to have no inuence or are slightly repellent. Frequently two or more pheromones are released during a behavioural situation, sometimes from different castes....
Posted on: 02 March, 2017
Author: Alexander P
Sex pheromones in the reproductive isolation of lepidopterous species matter. Throughout millions of metamorphoses, evolutionary processes in the Lepidoptera have resulted in many differences in morph... Sex pheromones in the reproductive isolation of lepidopterous species matter. Throughout millions of metamorphoses, evolutionary processes in the Lepidoptera have resulted in many differences in morphology, biology and behavior; not the least subtle of these changes being in the chemical communication systems developed by the various species. Most moth species utilize chemical emanations as a primary stimulus in their specialized mating behavior and the evidence is increasing that in many instances these specialized olfactory...
Posted on: 02 March, 2017
Author: Alexander P
Wynne-Edwards (1962), while discussing the problem of pheromonal homeostasis, i.e. self regulation of natural populations of animals, introduced the concept of ‘epideictic displays’. He s... Wynne-Edwards (1962), while discussing the problem of pheromonal homeostasis, i.e. self regulation of natural populations of animals, introduced the concept of ‘epideictic displays’. He suggested that these are necessary to allow animals to regulate their pheromone numbers and that the special sites on which animals deposit their scent are part of these displays. Most frequently these special sites for scent deposition are dung- hills. Many species of animals form dung-hills (Altmann 1969; Mykytowycz and Gambale...
Posted on: 02 March, 2017
Author: Alexander P
A very few components of pheromone secretions have been applied singly to leaves on ight routes and found to make them attractive (Kullen- berg, 1973), but extensive investigations are needed. Kulle... A very few components of pheromone secretions have been applied singly to leaves on ight routes and found to make them attractive (Kullen- berg, 1973), but extensive investigations are needed. Kullenberg (1973) also collected leaves pheromone-marked by Psithyrus bohemicus males and presented them elsewhere in the ight zone; males of P. bohemicus were attracted to them and deposited more scent in the vicinity. In experiments conducted in large cages...
Posted on: 02 March, 2017
Author: Alexander P
Identication of the chemical components of the Nasonov pheromone has been a slow process and may not yet be completed. Those so far identied are given in Table 13.1 and Fig. 13.1. Table 13.1 Identi... Identication of the chemical components of the Nasonov pheromone has been a slow process and may not yet be completed. Those so far identied are given in Table 13.1 and Fig. 13.1. Table 13.1 Identication of components of Nasonov pheromone. The tentative identication by Weaver et al. (1964) of citral as a minor component of the Nasonov pheromone was conrmed by Shearer and Boch (1966)....