An Australian native bee believed extinct is found after a 97 year absence from the records.
 |
Pharohylaeus lactiferus
IMAGE: James Dorey Photography |
The
Journal of Hymenoptera Research 81:165-180,
25 February 2021:
Missing
for almost 100 years: the rare and potentially threatened bee,
Pharohylaeus lactiferus (Hymenoptera, Colletidae)
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.
.jfif)
.jfif)
