Chemical Ecology of Astigmatid Mites. LXXI. Neryl Formate (Z)-3,7-Dimethyl-2,6-octadienyl Formate as The Alarm Pheromone of Tyroborus lini Oudemans 1924, and Its Recovery after Forced Discharge

Abstract

The presence of the alarm pheromone was demonstrated in the hexane extract of an acarid mite Tyroborus lini Oudemans 1924. The active fraction derived from an SiO 2 column chromatography of the mite extract was identified as neryl formate, (Z)-3,7-dimethyl-2,6-octadienyl formate by GC/MS and GC analysis. The synthesized neryl formate was shown to be active at 0.05-1 ng dose. Males contained 0.08 ng of the compound on average, and females 0.16 ng on average. The alarm pheromone was a component present in the opisthonotal gland. Once totally discharged from the gland upon disturbance, it took seven days before the pheromone content reached to its original level in the gland, whereas other compounds recovered within 60 hrs. The reason remains obscure at present.

Chemical Ecology of Astigmatid Mites LXXIII. Neral as an Alarm Pheromone of the Acarid Mite, Oulenzia sp. (Astigmata: Winterschmidtiidae)

“…This fact indicates that total discharge from either sex is necessary to release the alarm pheromone behavior among test mites. The same situation, total discharge of an active component required, has been evidenced in at least two other cases of R. robini (Mizoguchi et al, 2003) and T. lini (Tomita et al, 2003), and seems to be a common phenomenon in alarm pheromones. For better understanding of mite's multiple pheromone systems, further evidence must be accu mulated to investigate the condition, in which alarm pheromones function in Astigmata.…”

“…The activity was evaluated as reported (Tomita et al, 2003) with minor modifications. A cover dish with an appropriate mite number as described above was placed upside down on a sheet of paper, on which many circles (6 mm in diameter) were previously printed.…”

“…Chemical structures of the pheromones so far known are classified into three groups; 1) monoterpenes, 2) aromatics and 3) hydrocarbons (Kuwahara, 1999). The monoterpenes consist of five compounds; neryl formate in six species [four species belong to the genus Rhizoglyphus (Akiyama et al, 1997), Tyroborus lini (Tomita et al, 2003), and Tyrophagus putrescentiae (Kuwahara et al, 1975)], neral in five species [Carpoglyphus lactis (Kuwahara and Suzuki, 1983), Glycyphagus domesticus (Kuwahara et al, 1991a), Suidasia medanensis , Lardoglyphus konoi (Kuwahara et al, 1980) and Schwiebaea elongata ], geranial in Histiostoma laboratorium (Kuwahara et al, 1991b), isopiperitenone in Tyrophagus similis (Kuwahara et al, 1987) and β-acaridial in Tyrophagus longior (Noguchi et al, 1998). The aromatic compound 2-hydroxy-6-methylbenzaldehyde functions as the pheromone in Tyrophagus perniciosus (Leal et al, 1988).…”

“…Based on behavioral observations (Kuwahara et al, 1975), the presence of an alarm pheromone is also conceivable. A bioassay method (Tomita et al, 2003) originally devised for the present species was successfully applied for the study. We report here the identification of neral as the alarm pheromone of Oulenzia sp.…”

S-isorobinal as the female sex pheromone from an alarm pheromone emitting mite, Rhizoglyphus setosus

“…Although neryl formate (active at 100 ng) has been identified from the species as the only active component of the alarm pheromone (Akiyama et al 1997), its activity seems to be underestimated. The activity of neryl formate itself and its combination with the sex pheromone should be re-examined in future, using a new assay method developed by Tomita et al (2003).…”