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....
Continue ReadingPosted on: 02 March, 2017
Author: Alexander P
There are various reasons why young individuals may be kept isolated from other members of their pheromone group by being confined to special sites. Thus they may need better protection from predators... There are various reasons why young individuals may be kept isolated from other members of their pheromone group by being confined to special sites. Thus they may need better protection from predators and adverse climatic conditions or may have to be kept closer to sources of food and water or protected from deliberate or accidental injury by conspecifics. During the course of amatory behavior prior to mating in...
Continue ReadingPosted on: 02 March, 2017
Author: Alexander P
Let us discuss the top pheromones. The term aphrodisiac is widely used to describe this phenomenon, but care should be exercised in its use because of anthropomorphism, the tendency of anecdotal obser... Let us discuss the top pheromones. The term aphrodisiac is widely used to describe this phenomenon, but care should be exercised in its use because of anthropomorphism, the tendency of anecdotal observations to be given more credence than they deserve, and the assumption that an aphrodisiac is always successful. Male aphrodisiacs are wide- spread and most well known from the Lepidoptera, but even in this group we know...
Continue ReadingPosted on: 02 March, 2017
Author: Alexander P
All kairomone-responding species begin to arrive at, or very shortly after, the initial attack of the host and are thus present and ying in an environment permeated by scolytid aggregation pheromones... All kairomone-responding species begin to arrive at, or very shortly after, the initial attack of the host and are thus present and ying in an environment permeated by scolytid aggregation pheromones. Significantly, all are entomophagous insects which are intimately associated with bark beetles and depend on them as larval and or adult food. The beetles assures simultaneously continued response of female beetles to the area of pheromone release. The...
Continue ReadingPosted 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...
Continue ReadingPosted on: 02 March, 2017
Author: Alexander P
Orientation to a host (or to aggregation pheromones) must inevitably be in opposition to dispersal behavior. The behavioral transition involved has been investigated for aphids (Kennedy and Booth 1963... Orientation to a host (or to aggregation pheromones) must inevitably be in opposition to dispersal behavior. The behavioral transition involved has been investigated for aphids (Kennedy and Booth 1963a, b) and can be explained in terms of «hitting stimulus threshold levels (Johnson 1969). At the beginning of the dispersal phase, the insect has a very low threshold for dispersal stimuli, but a very high concentration. The threshold for host-positive stimuli. In...
Continue ReadingPosted on: 02 March, 2017
Author: Alexander P
Individual distance as any other pheromone space varies with the needs or requirements of an individual at a given time. As the production of odor from the skin glands is under the control of sex horm... Individual distance as any other pheromone space varies with the needs or requirements of an individual at a given time. As the production of odor from the skin glands is under the control of sex hormones, individual distances of aggressive animals or those in a pheromone reproductive state will be increased automatically with a repelling or attracting effect depending on their physiological state. Thus...
Continue ReadingPosted on: 02 March, 2017
Author: Alexander P
As further evidence of complexity of male pheromone odor compared with female odorour research shows the preliminary characterization of caudal organ odors of Apodemus avicollis Melchior (Stoddart, u... As further evidence of complexity of male pheromone odor compared with female odorour research shows the preliminary characterization of caudal organ odors of Apodemus avicollis Melchior (Stoddart, unpublished). Several peaks peculiar to the male are present and their identification and isolation are the subject of continuing pheromone studies. Mention was made above of the dual role played by the scent producing apparatus of some small mammals. There seems little doubt that cutaneous...
Continue ReadingPosted on: 02 March, 2017
Author: Alexander P
Although males’ initial responses to virgin and old mated queens were similar, they attempted to mate with young queens but not old ones (Free, 1971). Differences in the urge to mate could be ac... Although males’ initial responses to virgin and old mated queens were similar, they attempted to mate with young queens but not old ones (Free, 1971). Differences in the urge to mate could be accounted for by differences in the amount and composition of the queens’ sex attractant, or some other odour change associated with age or ovary development. Free (1971) found that the head and thorax...
Continue ReadingPosted on: 02 March, 2017
Author: Alexander P
It is the intent of this article to describe the essential biological role of aggregation pheromones in the processes of scolytid host selection and mass attack. In addition, the role of scolytid pher... It is the intent of this article to describe the essential biological role of aggregation pheromones in the processes of scolytid host selection and mass attack. In addition, the role of scolytid pheromones in guiding associated insects to scolytid-attacked hosts will be examined as outlined in g. 8.2. Specic examples are taken from well researched species to illustrate each step. It is not the intent of this...
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