An Australian native bee believed extinct is found after a 97 year absence from the records.
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| Pharohylaeus lactiferus IMAGE: James Dorey Photography |
The Journal of Hymenoptera Research 81:165-180, 25 February 2021:
James B. Dorey
Abstract
The Australian endemic bee, Pharohylaeus lactiferus (Colletidae: Hylaeinae) is a rare species that requires conservation assessment. Prior to this study, the last published record of this bee species was from 1923 in Queensland, and nothing was known of its biology. Hence, I aimed to locate extant populations, provide biological information and undertake exploratory analyses relevant to its assessment. Pharohylaeus lactiferus was recently rediscovered as a result of extensive sampling of 225 general and 20 targeted sampling sites across New South Wales and Queensland. Collections indicate possible floral and habitat specialisation with specimens only found near Tropical or Sub-Tropical Rainforest and only visiting Stenocarpus sinuatus (Proteaceae) and Brachychiton acerifolius (Malvaceae), to the exclusion of other available floral resources. Three populations were found by sampling bees visiting these plant species along much of the Australian east coast, suggesting population isolation. GIS analyses used to explore habitat destruction in the Wet Tropics and Central Mackay Coast bioregions indicate susceptibility of Queensland rainforests and P. lactiferus populations to bushfires, particularly in the context of a fragmented landscape. Highly fragmented habitat and potential host specialisation might explain the rarity of P. lactiferus. Targeted sampling and demographic analyses are likely required to thoroughly assess the status of this species and others like it.
Keywords
Conservation, extinction risk, fragmentation, Hylaeinae, invertebrate conservation, Queensland, wildfire, rainforest
Introduction
The greatest threats to ecosystems and species worldwide are habitat loss, fragmentation and degradation (Vie et al. 2009). Australia has already cleared over 40% of its forests and woodlands since European colonisation, leaving much of the remainder fragmented and degraded (Bradshaw 2012). The vast majority of clearing has occurred on freehold and leasehold land and for animal agriculture (Evans 2016). In particular, Queensland is a contemporary land-clearing hotspot and is responsible for more than half of all land-clearing in Australia over the past four decades (Evans 2016). It is a failing of state and federal government policy and regulation that land clearing in Queensland continues at rates that should be of concern both nationally and internationally (Reside et al. 2017).
Despite the ecological importance of Australian native bees, we know very little about their biology (Batley and Hogendoorn 2009) or conservation status. North Queensland hosts high species richness and endemism (Crisp et al. 2001; Orme et al. 2005; Hurlbert and Jetz 2007) and several bee genera that are found nowhere else in Australia (Houston 2018; Smith 2018). These restricted bee genera include: Ctenoplectra Kirby (Apidae: Apinae), Nomada Scopoli (Apidae: Nomadinae), Mellitidia Guérin-Méneville (Halictidae: Nomiinae), Reepenia Friese (Halictidae: Nomiinae), Patellapis Friese (Halictidae: Halictinae) and Pharohylaeus Michener (Colletidae: Hylaeinae).
Pharohylaeus has only two described species: P. papuaensis Hirashima & Roberts in Papua New Guinea and P. lactiferus (Cockerell) in Australia (Houston 1975; Hirashima and Roberts 1986). Both species are relatively large (9–11 mm), robust, mostly black with distinctive white facial and body markings, and have the first three tergal segments enlarged and enclosing the others. The former is known only from two females which were collected on Syzygium aqueum (Burm.f.) Alston (Myrtaceae) in 1982 (Hirashima and Roberts 1986). No published records of P. lactiferus have been made since the third of January 1923, when three males were collected in the Atherton Tablelands; in May of 1900 a male and a female were collected in Mackay while another female was collected in Kuranda prior to 1910 (Cockerell 1910; Houston 1975). However, the collection localities of these specimens are imprecise and no biological data were recorded.
Due to the dearth of biological information on P. lactiferus prior to this study, I aimed to locate extant populations and contribute biological information as part of a broader bee survey. Because of this, much of what follows are exploratory analyses of the potential risks for P. lactiferus and suggestions for future research. Hence, I undertook a series of post-hoc analyses in order to provide insights into the biology, ecology and potential extinction risks associated with P. lactiferus. I provide insights into the circumstances of the rediscovery of P. lactiferus and what is now known of its floral and habitat associations. I also explore spatial data relating to P. lactiferus (vegetation association, potential fire risks and occurrences) and my sampling methods (for potential biases). The possible floral and habitat specialisation along with the rarity of P. lactiferus raises concerns about its conservation status. I further highlight the need for preservation of remnant vegetation and better arthropod-diversity monitoring, particularly for at-risk and phylogenetically important species.
Methodology can be found here.
