The distribution, abundance and life cycle of the pest mites Balaustium medicagoense (Prostigmata: Erythraeidae) and Bryobia spp. (Prostigmata: Tetranychidae) in Australia

Abstract

Balaustium medicagoense and Bryobia spp. have recently been identified by the Australian grains industry as emerging pests of winter grain crops and pastures. While reports of damage by these mites appear to have increased in the last decade, limited research has been conducted on their biology and ecology. Here the distribution and seasonal abundance patterns of Bryobia spp. and Ba. medicagoense in southern Australia are investigated. Bryobia spp. had a more widespread distribution than Ba. medicagoense. An Ecological Niche Model for the distribution of Ba. medicagoense constructed using MAXENT predicted the distribution of this species well, and identified associated climatic factors including summer and winter temperature variables and winter precipitation. Monthly sampling suggested that Ba. medicagoense had two generations per year and was active from March until December, with a likely diapause period in summer. The seasonal abundance and life cycle of two species of Bryobia (Bryobia sp. IX and Bryobia sp. I) differed. Bryobia sp. IX had two generations per year, was active from March until December, and was likely to be in diapause over summer. Bryobia sp. I did not appear to have a diapause stage, and had approximately four generations per year. Activity periods of these mites overlapped with those of the pest mite species Halotydeus destructor and Penthaleus major. A survey of pest outbreaks and chemical control failures suggested that while H. destructor and the Penthaleus species remained important pests, outbreaks of Ba. medicagoense and Bryobia spp. had increased. The findings highlight the need to develop effective and sustainable management strategies for these mites.

Understanding niche shifts: using current and historical data to model the invasive redlegged earth mite, Halotydeus destructor

“…Exact localities were recorded with using a Navman global positioning system (Model iCN 320; MiTAC International Corp., Taipei, Taiwan). Data from pest outbreak surveys were also included (see Arthur et al. , 2011).…”

“…Exact localities were recorded with using a Navman global positioning system (Model iCN 320; MiTAC International Corp., Taipei, Taiwan). Data from pest outbreak surveys were also included (see Arthur et al, 2011). Halotydeus destructor specimens were identified from samples provided by agricultural workers following outbreaks or control failures from 2005 to 2007, contributing another 29 points.…”

“…However, 30 yr later, further sampling efforts in eastern Australia show that H. destructor existed further north and inland than earlier reported (Weeks & Hoffmann, 1999; Robinson & Hoffmann, 2001). More recently, distribution data from pest outbreaks, control failures and field observations indicate that H. destructor occurs in hotter and drier areas, well beyond the long‐term average 205‐mm rainfall isohyet (Arthur et al. , 2011).…”

“…However, 30 yr later, further sampling efforts in eastern Australia show that H. destructor existed further north and inland than earlier reported (Weeks & Hoffmann, 1999;Robinson & Hoffmann, 2001). More recently, distribution data from pest outbreaks, control failures and field observations indicate that H. destructor occurs in hotter and drier areas, well beyond the long-term average 205mm rainfall isohyet (Arthur et al, 2011). If the 1960s range of this species represented an equilibrium distribution, these data suggest a recent range expansion, perhaps because of climatic changes (in particular rainfall), changes in agricultural practice and/or an adaptive shift in physiology.…”

Mites on Plants

“…Phytophagy has arisen within at least seven clades of Prostigmata, including two major radiations of obligate parasites of vascular plants (Eriophyoidea and Tetranychoidea) and several less evolutionarily successful experiments within other lineages (Erythraeidae, Eupodoidea, Stigmaeidae, Tydeidae and Tarsonemidae) that feed on vascular plants, bryophytes, and algae. Balaustium medicagoense (Erythraeidae) is an especially interesting example because it is a general feeder considered both a predator of pests and a pest in grain and pasture crops (Arthur et al 2011 ). Tarsonemid mites are an especially interesting example because at least four independent evolutions of vascular plant-parasitism from mycophagous ancestors seem to have occurred (Lindquist 1986(Lindquist , 1998.…”