Could the acarid mite Tyrophagus putrescentiae (Schrank) be used as an environmental thermometer?

ABSTRACT

A proof-of-concept for the reconstruction of historical temperatures from museum collections of a commonly-occurring saprophagous mite is recounted. Technological readiness level 3 (TRL3) and TRL4 stage-gates were passed for a multiplex bioassay of ambient temperature using re-purposed laboratory data of setal and body sizes of female Tyrophagus putrescentiae (Acaridae: Astigmata) individuals. Higher temperatures yielded smaller mites with shorter setae. Partial predictive utility of environmental temperature using a composite scale measure was found for mites field-collected in the UK ($\equiv$TRL5 validation of use). Tyrophagid size in the wild appears individually variable and confounded in the cooler seasons through possible local heating effects (perhaps by virtue of their presence in numbers). Mite shape may change seasonally. Geographically dispersed detailed data-logging of micro-temperatures in the field together with targeted collection and characterization of mites at the same locations and measures of their local density is needed in order to advance such biotechnology to any demonstration of effective use all year round ($\equiv$TRL6) and final use in museum research.

KEYWORDS:

• Acaridae
• climate inference
• natural history collections-based research
• phenology
• shape
• size

Acknowledgements

All new data generated and analysed by the author during this study at the Oxford Centre for Industrial and Applied Mathematics plus any model specifications are included in this published article - or in compliance with EPSRC’s open access initiative, the TRL5 ‘all-complete’ dataset of Tyrophagus putrescentiae individuals is available from doi.org/10.5287/bodleian:00o5Y00Y0. Thanks go to to the generosity of: - the late Don Griffiths for access to the dataset from Shepherd (1982); Barry OConnor, the University of Michigan for repeated help with astigmatid classification; Charley Eiseman and Pavel Klimov for permission to reuse their colour photographs. Above all, I thank my wife Diane for supporting my involvement in this field over many years. The author is a Royal Society Industrial Fellow (IF110047) at the Mathematical Institute, University of Oxford.

Disclosure statement

The author declares that they have no known conflicts of interest. No competing claims are known. This article does not contain any studies with human participants or vertebrate animals performed by any of the authors.

Additional information

Funding

Self-funded study.