Chemical Ecology of Astigmatid Mites LIX Neral, the Alarm Pheromone of Schwiebea elongata (Banks) (Acari: Acaridae) (original) (raw)
Related papers
Applied Entomology and Zoology, 2002
Although neral [(Z)-3,7-dimethyl-2,6-octadienal] has been known as the alarm pheromone of Schwiebea elongata, reinvestigation of the pheromone resulted in recognition of another function as an attractant. The alarm pheromone activity was confirmed at a dose of one female equivalent of the hexane extract, whereas the attractant pheromone activity was observed at 0.1 female equivalent. Although no attractant activity was recovered in fractions of the silica gel (SiO 2) column eluate, the synthetic neral manifested both activities; the attractant activity at 3 ng and 1 ng with a convex dose-response relationship, and the alarm pheromone activity at 30 ng. A female contained 30.4 ng of neral on average and a male 0.7 ng on average. This is the first example among astigmatid mites demonstrating that a single mite compound emitted from the opisthonotal gland exhibits two pheromonal functions, alarm pheromone and also attractant, at different doses.
2010
The two-spotted spider mite Tetranychus urticae Koch is one of the economically most important pests in a wide range of outdoor and protected crops worldwide. Its control has been and still is largely based on the use of insecticides and acaricides. However, due to its short life cycle, abundant progeny and arrhenotokous reproduction, it is able to develop resistance to these compounds very rapidly. As a consequence, it has the dubious reputation to be the"most resistant species" in terms of the total number of pesticides to which populations have become resistant, and its control has become problematic in many areas worldwide. Insecticide and acaricide resistance has also been reported in the ectoparasite Sarcoptes scabiei, the causative organism of scabies, and other economically important Acari, such as the Southern cattle tick Rhipicephalus microplus, one of the biggest arthropod threats to livestock, and the parasitic mite Varroa destructor, a major economic burden for beekeepers worldwide. Although resistance research in Acari has not kept pace with that in insects, a number of studies on the molecular mechanisms responsible for the resistant phenotype has been conducted recently. In this review, state-of-the-art information on T. urticae resistance, supplemented with data on other important Acari has been brought together. Considerable attention is given to the underlying resistance mechanisms that have been elucidated at the molecular level. The incidence of bifenazate resistance in T. urticae is expanded as an insecticide resistance evolutionary paradigm in arthropods.
Pest control by mites (Acari): present and future
Acarologia, 2014
This essay reviews advances in the systematics of mite families containing members that are acarine biocontrol agents (ABAs), including the Phytoseiidae which have several strains or races. Additions to the roster of mites that affect pests (including weeds and pathogens), and of pests that may be, or are, significantly affected by ABAs, were noted. The various pest-debilitating mechanisms used by ABAs, including predation, parasitism, parasitoidism, parasitic castration, competition as well as reductions in weed and phytopathogenic fungal growth are listed. The affected targets include agricultural, veterinary and medical pests, as well as weeds, nematodes and fungi. The effect of intraguild predation on the ABAs' ability to affect pests is discussed, along with other organisms that increase the controlling impact of ABAs. The influence of host plants, including their architecture, leaf surfaces, domatia, pollen, genetically modified plants (GMOs) and volatiles are then reviewed. Then come mite feeding on soil-inhabiting pests and the newlydiscovered effects of arbuscular mycorrhizal (AM) fungi. ABA feeding on weeds and on nematodes is briefly discussed next, along with the few known ABA diseases. The effect of plant-protection chemicals are then considered, followed by new techniques for the better implementation of ABAs. These include mass rearing, modes of distribution, longterm maintenance and the application of molecular methods to determine quantitative and qualitative feeding rates. This review ends with suggestions for further research, including more collecting and assaying of ABAs (especially indigenous species), determining the effects of secondary predators and of light regimes in greenhouses, and increasing studies on the role of volatiles of plant and nematode source, and of ABAs as vectors of pest diseases.
Journal of the Acarological Society of Japan, 2004
Hexane extracts derived from an unidentified Oulenzia sp. showed the alarm pheromone activity. The extract was composed of the following 10 compounds; tridecane, neral, pentadecane, dodecane, 3hydroxybenzene-1,2-dicarbaldehyde, geranial, (Z)-7-pentadecene and 7-hydroxyphthalide in decreasing order together with two unknown compounds. After fractionation with a silica gel column, the active fraction consisted of a mixture of neral and geranial. Neral was found to show the activity, but geranial was not. Neral was, therefore, identified as the alarm pheromone of this species.
Journal of the Acarological Society of Japan, 2003
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.
Acarinaria in associations of apid bees (Hymenoptera) and chaetodactylid mites (Acari)
Invertebrate Systematics, 2007
Acarinaria are specialised structures on the bodies of insects that harbour dispersing mites, providing a secure attachment place for the mites. The structures are best known among bees and wasps. Their presence remains enigmatic, however, since the associated mites often have negative or neutral effects on their hosts. A new hypothesis explaining the origin of the acarinarium as a specialised defence mechanism is proposed. In nests with partitions (as constructed by many bees and wasps), parasitic or cleptoparasitic mites are rarely found in all cells. They negatively interact only with host larvae developing in infested cells and apparently cannot disperse within the nest to attack others in the developing brood before bee emergence. Only when emerging bees break the partitions can the mites reach other hosts. We propose that acarinaria serve to concentrate unwanted mites, reducing the chance that they will disperse to other members ofthe brood as the infested host leaves the nest. Development of special mite pouches (acarinaria) by hymenopteran hosts presumably increases the likelihood that all mites will stay with the individual(s) with reduced fitness, thereby reducing their effect on other bees in the brood. This paper reviews the associations between chaetodactylid mites and long-tongued bees (Apidae and Megachilidae). Only apid bees (Apidae) have acarinaria; megachilid bees, which barbour species of Chaetodactylus that usually kill the bee larvae, do not possess acarinaria. The following associations involving previously undescribed acarinaria or mite species are reported: Achaetodactylus ceratinae (axillar acarinarium on Ceratina nigriceps); Roubilda latebrosa, sp. nov. (metasomal acarinarium on Tetrapedia sp.), Sennertia argentina (genital acarinarium on Xylocopa fimbriata), Sennertia devincta, sp. nov., Sennertia sayutara, sp. nov. (metasomal acarinaria on Ceratina (Zadontomerus) spp.), Sennertia lauta , sp. nov. and Sennertia ratiocinator, sp. nov. (incipient scutellar-metanotal acarinarium on Xylocopa (Zonohirsuta) spp.). In the latter case, the mites display a remarkable difference in the attachment sites between male and female hosts. In females, the mites are phoretic in a groove between the scutellum and metanotum (scutellar-metanotal acarinarium), whereas on males, mites attach to the hairs of the anterior scutum.