Pheromone flight initiation

Flight Initiation Pheromones. The mating flights of many species of carpenter ants are initiated by male mandibular gland secretions (148). These chemical stimulators of female flight appear to constitute relatively species-specific blends of compounds that are dominated by compounds such as 2,4-dimethyl -2-hexenoic acid, methyl 6-methyl salicylate (XXXIV), methyl anthranilate (XXXIX), 10-methyldodecanoic acid, and the lactone mellein (XL) (149, 150). Recently, the sex-specific blend of... 

Release rates of acetate esters of (2S,3S,7S)-3,7-dimethylpentadecan-2-oll and (2S,3R,7R)-3,7-dimethyltridecan-2-ol 3 from polyethylene and cotton dispensers have been measured at different temperatures and loadings. Adjustment of the initial pheromone load on polyethylene for expected temperatures should permit the formulation of a constant release rate during the entire flight period. Successful field trapping trials for N. sertifer were carried out in Sweden, the Czech Republic, Italy, and Greece [29]. 

We have also tried to attach filter papers with pheromone, control odors, and no odor, respectively, in the four comers of the laboratory or classroom near the ceiling. Moths can be released one by one in the center of the room, and their flight pattern monitored and scored. Dr. Stephen Teale initiated this experiment. 

It seems likely that bark beetles orient anemotactically in flight to attractive trees (see Carde, Chapter 5), though there is no experimental evidence to support this. The upwind walking response of beetles to a source of pheromone in the laboratory indicates that they can follow an odor plume to its source, at least while walking (Wood et al., 1966 see also Bell, Chapter 4). Increasing concentration of pheromone near a source may be used for final orientation. There appears to be a maximum pheromone concentration above which beetles do not continue orientation, but rather land and initiate new attacks. This explains why trees are often killed in groups around one susceptible tree that is attacked first. 

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