Genetic Markers Indicate a New Species Complex of Emerging Pest Mites in Australian Grains

Abstract

Balaustium medicagoense Meyer & Ryke (Acari: Erythraeidae) and Bryobia spp. Koch (Acari: Tetranychidae) are significant emerging pests in Australian grains and pastures. Despite this, there is limited information known on their basic biology, such as species status and reproductive modes, making it difficult to develop effective and sustainable control strategies. The species/strain status of Balaustium and Bryobia mites from southern Australia was examined using a combination of mitochondrial and nuclear DNA sequence data. In addition, the amplified fragment length polymorphism (AFLP) method was used to examine the reproductive mode and genetic diversity of Ba. medicagoense from 16 populations within southern Australia. Results indicate that there is only one species of Balaustium (Ba. medicagoense) and as many as seven species of Bryobia mites currently present in grain crops, pastures and roadsides within southern Australia. The Bryobia species complex consists of four recently described lineages (Bryobia sp. I, Bryobia sp. IV, Bryobia sp. VII, and Bryobia praetiosa Koch) and three additional genetic lineages (Bryobia sp. VIII, Bryobia sp. IX, and Bryobia sp. X) that have not been described previously. Bryobia sp. VIII, B. sp. IX, and B. sp. I seem to be the most abundant species present in Australian broadacre agriculture (i.e., land suitable for farms practicing large-scale crop [agriculture] operations). The AFLP data revealed that Ba. medicagoense reproduces asexually and that genetic diversity was low with only 10 genotypes found. These findings indicate a new complex of pest mites are present within Australian grain crops and pastures and this has implications for their control.

Global analysis reveals that cryptic diversity is linked with habitat but not mode of life

“…Our inability to distinguish among different biological units can also have serious practical implications. For instance, it could lead to misdirected efforts to conserve species, eradicate invasive species or control pests and diseases (Armstrong & Ball, ; Pringle et al ., ; Witt et al ., ; Pérez‐Ponce de León & Nadler, ; Arthur et al ., ; Nadler & Pérez‐Ponce de León, ; Burger et al ., ). However, there has been no serious attempt at identifying the lifestyles or environmental conditions propitious for the formation of cryptic taxa.…”

Cryptic speciation in the Acari: a function of species lifestyles or our ability to separate species?

“…Navia et al 2013a ; Walter and Proctor 2013 ), their misidentification may have serious negative consequences for human activities (e.g. Anderson and Trueman 2000 ; Bernasconi et al 2002 ; Arthur et al 2011 ; Beati et al 2013 ; Matsuda et al 2013 ; Miller et al 2013 ; Navia et al 2013b ; Skoracka et al 2013 ; Burger et al 2014 ). Indeed, neglected cryptic diversity may hamper the development of technologies and management tools in medicine, agriculture and other important fields, due to the inability to link cryptic species to their unique epidemiological, pathogenic or host-specific traits (Armstrong and Ball 2005 ; Pringle et al 2005 ; Bickford et al 2007 ).…”

The wheat curl miteAceria tosichella(Acari: Eriophyoidea) is a complex of cryptic lineages with divergent host ranges: evidence from molecular and plant bioassay data

“…These complexes are useful models for studying ecological and evolutionary processes because their speciation may be recent and driven by observable phenomena (Boissin, Stöhr & Chenuil, 2011). Moreover, elucidation of the cryptic structure of species complexes of parasites, pathogens, pests, and invasive species can mitigate serious negative medical or economic consequences caused by ignorance of their existence (Pringle et al, 2005;Bickford et al, 2007;Arthur, Miller & Weeks, 2011;Chu et al, 2011;Telle et al, 2011). The advent of rapid DNA sequencing technologies in recent years has provided new tools for exploring genetic variation and discriminating among morphologically cryptic lineages (Hebert et al, 2003a;Hebert, Ratnasingham & deWaard, 2003b;Avise, 2004;Bickford et al, 2007;Hill et al, 2012).…”