A new Australian record of a Parajapidae (Diplura): A potential pest of wheat

Parajapyx isabellae (Grassi, 1886) is recorded for the first time from Australia. It is a cosmopolitan soil species found in Europe, North and South America and Asia. Womersley last studied Australian Parajapygidae 80 years ago, listing a single endemic species for the genus Parajapyx Silvestri, 1903, sensu stricta. In 2017, an unidentified Parajapyx was found in deep soil under wheat in winter, spring and summer at Harden, New South Wales, in a long-term tillage trial. It was most abundant in the minimum tillage/stubble retained plots in soil below 5 cm but rarely observed in the conventionally tilled/stubble burned plots. The same field experiment was sampled five times using the same methods over 3 years from 1993-95 but no specimens of Diplura were collected. The specimens were identified as P. isabellae using morphology and confirmed with the DNA barcoding sequence data. Most species of Parajapygidae are carnivores feeding on small arthropods but there are records from North America, Europe and Hawaii of P. isabellae feeding on roots of wheat and other agricultural crops. We provide here illustrations of species P. isabellae so that crop scientists in Australia are aware of the potential pest and can identify it. Sequence data indicate that the population may have originated from two sources.