Posted 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 combination of response eliciting and inhibiting factors, then triggers the shifting of attack to unoccupied host material within the sphere E of the pheromone population attractant. Of considerable interest is the ubiquitous presence of cis- or transverbenol. Either or both isomers may serve as contact pheromones in species (Vlté et al. 1972), but although trans-verbenol is present in at least five Dendroc- tmms species, it apparently serves as a major aggregating pheromone compound only in D. ponderosae (Pitman et al. 1968). The definitive role of host-tree monoterpenes as synergistic components of an ggregating pheromone complex was elucidated by the isolation of . myrcene from the frass of female D. brevicomis (Silverstein, 1970) and the subsequent demonstra- lnn that in eld tests the pure compound was synergistic with the pheromone compound, brevicomin (Bedard et al. 1969). The physical environment must have ight and the appropriate blend of host and beetle-produced volatiles must present on the wind. The responding beetles perceive the odor with their annnne (Borden and Wood 1966; Payne 1970, 1971) and, as established for ight is a key step in the concentration phase according to http://sundowndivers.org/highest-rated-pheromone-colognes-2017/ It commits the respond- beetles to make contact with the host in or on which they may find others of first-attacking sex or prospective mates, as the case may be. Again duration of t (Bennett and Borden 1971) and concurrent lipid metabolism (Atkirils 1969; ompeon and Bennett 1971) apparently predispose beetles to respond. It is not whether responding beetles cease ight in response to pheromones. For males of Dendroctonus pseudotsugae ceased ight in response to either r of host phloem tissue or attractive female frass (Bennett and Borden 1971). 9, ee It has alighted, in responding beetle may be inhibited from further ight by A Presence of Volatile Pheromones Contact with or presence of the odor of attractive frass almost completely inhibited take-offs in both sexes of (Borden 1967). Thus inhibited from response to dispersal stimuli, the responding beetle is free to perform a new series of behavioral tasks. Orientation to prospective mates: Both odor and sound are used in the short-range communication involved in location and recognition of a mate. Contact with male frass is sufcient to induce female Ips calligraphus (Germar) to search for and nd the entrance to a male nuptial chamber (Wilkinson et al. 1967). Physical presence of a male is not necessary in I. paraconfusus. When females encountered male frass around articial entrance holes, they searched for and entered the holes just as they would the normal entrance to a nuptial chamber (Barr 1969). Stridulation by female Ips occurs when they encounter the entrance to a nuptial chamber, apparently in response to male-produced pheromones. In response, the male admits the female into the nuptial chamber (Wilkinson et al. 1967; Barr 1969). Source: Free Articles from ArticlesFactory.com Alexander P is a blogger that studies pheromones. He lives in Los Angeles, CA.