Verified and potential pathogens of predatory mites (Acari: Phytoseiidae)

Abstract

Several species of phytoseiid mites (Acari: Phytoseiidae), including species of the genera Amblyseius, Galendromus, Metaseiulus, Neoseiulus, Phytoseiulus and Typhlodromus, are currently reared for biological control of various crop pests and/or as model organisms for the study of predator-prey interactions. Pathogen-free phytoseiid mites are important to obtain high efficacy in biological pest control and to get reliable data in mite research, as pathogens may affect the performance of their host or alter their reproduction and behaviour. Potential and verified pathogens have been reported for phytoseiid mites during the past 25 years. The present review provides an overview, including potential pathogens with unknown host effects (17 reports), endosymbiotic Wolbachia (seven reports), other bacteria (including Cardinium and Spiroplasma) (four reports), cases of unidentified diseases (three reports) and cases of verified pathogens (six reports). From the latter group four reports refer to Microsporidia, one to a fungus and one to a bacterium. Only five entities have been studied in detail, including Wolbachia infecting seven predatory mite species, other endosymbiotic bacteria infecting Metaseiulus (Galendromus, Typhlodromus) occidentalis (Nesbitt), the bacterium Acaricomes phytoseiuli infecting Phytoseiulus persimilis AthiasHenriot, the microsporidium Microsporidium phytoseiuli infecting P. persimilis and the microsporidium Oligosproridium occidentalis infecting M. occidentalis. In four cases (Wolbachia, A. phytoseiuli, M. phytoseiuli and O. occidentalis) an infection may be connected with fitness costs of the host. Moreover, infection is not always readily visible as no obvious gross symptoms are present. Monitoring of these entities on a routine and continuous basis should therefore get more attention, especially in commercial mass-production. Special attention should be paid to field-collected mites before introduction into the laboratory or mass rearing, and to mites that are exchanged among rearing facilities. However, at present general pathogen monitoring is not yet practical as effects of many entities are unknown. More research effort is needed concerning verified and potential pathogens of commercially reared arthropods and those used as model organisms in research.

Symbiosis in an overlooked microcosm: a systematic review of the bacterial flora of mites

“…Moreover, infected mites developed symptoms such as body shrinkage, cessation of oviposition and even death. Accordingly, the bacterium was realized as a potential pathogen of predatory mites (Schütte and Dicke, 2008; Schütte et al 2008).…”

Biology, Predation, and Life Table of Cydnoseius negevi and Neoseiulus barkeri (Acari: Phytoseiidae) on the Old World Date Mite, Oligonychus afrasiaticus (Acari: Tetranychidae)

“…May be the prey ( O. afrasiaticus ) is considered unsuitable food for N. barkeri (G. J. de Moraes, personal communication). Schutte and Dicke (2008) reported unidentified microorganisms in association with some phytoseiids. Bacteria and microsporidia have been published by different authors.…”

Microbiomes of Two Pest Fly Species of Pennsylvania Mushroom Houses

“…Further, the Wolbachia identified in L. ingenua was from a completely different cluster (within the Supergroup E clade), a clade that has been previously associated primarily with springtails and several mite species [19,20]. One predatory mite (Hypoaspis aculeifer) known to be an effective biocontrol agent against both species of flies, was not observed or known to be in these mushroom houses, but even if it was present, it is not a species known to harbor Wolbachia [21,22]. Since the sequencing was conducted on whole flies (flies were too small to dissect for sufficient DNA for sequencing), we cannot exclude the possibility that the Wolbachia detected came from infected springtails or mites that may have been consumed by fly larvae in the mushroom mats.…”