Anonychomyrma inclinata sp. nov. (Hymenoptera: Formicidae): description, biology and interaction with the endangered bulloak jewel butterfly, Hypochrysops piceatus Kerr, Macqueen & Sands, 1969 (Lepidoptera: Lycaenidae)

Abstract

The ant Anonychomyrma inclinata sp. nov. is described. It is an arboreal species, nesting in hollows of living mature trees including Allocasuarina luehmannii, Angophora leiocarpa and various Eucalyptus species. Anonychomyrma inclinata can form colonies which are among the most populous recorded for an ant species in Australia, with over 10 000 workers and a total population of 170 000, including all castes. The ant forms extensive trails, forages for insects, collects nectar from a range of flowering plants including many mistletoes and collects honeydew from Hemiptera. The ant's distribution extends from northern inland New South Wales and south central inland Queensland, as far north‐east as Home Hill, on the Burdekin River. The ant is an obligate attendant of the immature stages of the endangered bulloak jewel butterfly, Hypochrysops piceatus Kerr, Macqueen & Sands, 1969, and the southern population of the sapphire azure, Ogyris aenone Waterhouse, 1902. The distribution of A. inclinata is much wider than that currently known for H. piceatus, suggesting that suitable breeding sites may exist for this rare butterfly in areas not previously surveyed. While A. inclinata appears relatively widespread and is able to utilise a wide range of tree species, it is reliant, like H. piceatus, on mature live trees and so is subject to threats including vegetation clearance, timber‐getting, grazing, and increased drought and fire frequency. Due to its critical importance in the life cycle of H. piceatus, any action taken to conserve the butterfly must also consider the importance of preserving healthy populations of A. inclinata.

Systematics of the Ogyris aenone (Waterhouse, 1902) complex (Lepidoptera: Lycaenidae): threatened Australian butterflies of national conservation significance

“…Host trees for the co-occurrence of these mistletoe and nesting attendant ants on which O. caelestia immature stages were found include Allocasuarina luehmannii, Eucalyptus tereticornis and Angophora leiocarpa. Lewis and Sands (2021) also recorded Anonychomyrma inclinata nesting in Eucalyptus crebra but we did not find the immature stages of the butterfly associated with this tree. On three occasions, immature stages were recorded on mistletoe growing on saplings of the host trees A. luehmannii and E. tereticornis.…”

The Life History of Hypochrysops piceatus Kerr, Macqueen & D.P.A. Sands, 1969 (Lepidoptera: Lycaenidae), a Threatened Butterfly from Australia

“…and Callitris spp. as major components in the overstorey (Lewis & Sands 2021). The habitats appear to be long unburnt and support extensive colonies of the attendant ant Anonychomyrma inclinata Lewis & D.P.A.…”

“…The attendant ant Anonychomyrma inclinata is an arboreal species that nests primarily in hollows of live mature trees of Allocasuarina luehmannii , but also in Angophora leiocarpa , Eucalyptus tereticornis Sm. and E. crebra F.Muell (Lewis & Sands 2021). The ants access the internal hollow branches and trunk via fissures, cracks and insect borer holes or through lightning scars and broken limbs.…”

“…Despite the wide spatial distribution of the attendant ant (Lewis & Sands 2021), with an estimated extent of occurrence of 205,300 km 2 (Beaver et al, 2023), H. piceatus appears to be a narrow-range endemic, currently known only from two locations (Fig. 4): Leyburn (Kerr et al 1969, Lundie-Jenkins & Payne 2000, Sands & New 2002), and Bendidee State Forest and adjacent areas c. 40 km NE of Goondiwindi (Moss 2001, Sands & New 2002), QLD.…”

“…Key threatening processes include habitat loss and degradation from multiple activities, such as land-clearing (for grazing, road/track widening) and selective removal of mature trees of Allocasuarina luehmannii (for turnery, firewood, fence posts etc. ), removal of dead and fallen trees supporting ant trails (for firewood), invasive weeds (grasses, cacti), rubbish dumping, and increased drought frequency and fire through climate change (Sands 1993, Dunn & Kitching 1994, Lundie-Jenkins & Payne 2000, Sands & New 2002, Valentine & Johnson 2012, Sands & Braby 2018, Lewis & Sands 2021, Geyle et al 2021). Lack of recruitment associated with natural tree death has also been identified as a key issue because the breeding trees are old and often senescent with dead or dying limbs.…”