Download Press Release - Faculty of Science, HKU

DEAN
Professor S Kwok
院長
郭新教授
FACULTY SECRETARY
Mrs A O M Tsang
院務主任
曾謝靄文女 士
FACULTY OF SCIENCE
THE UNIVERSITY OF HONG KONG
香港大學
理學院
Press Release
Looking for biodiversity? Follow the ants.
 An international team from HKU and OIST launches the first online “antmaps”
to visualise the global distribution of ants including 170 species from HK
August 6, 2015
Loss of biodiversity is a major concern for scientists and most governments around the world. Nevertheless, the
understanding of the composition and geographic distribution of global biodiversity is still largely incomplete. This
is best exemplified by the absence of synthesis on global distribution of insects, though their exceptional biodiversity
of over 1.1 million species represents the vast majority of species on Earth (with 50% to 90% of insect species still
undescribed/unknown). This knowledge gap represents one of the fundamental questions to be addressed in the
frontier of macroecological studies, facilitating the devising of efficient conservation plans.
Dr. Benoit Guénard, Assistant Professor of School of Biological Sciences at the University of Hong Kong (HKU), in
collaboration with Dr. Evan Economo from the Okinawa Institute of Sciences and Technology (OIST) Graduate
School, have spent four years addressing the knowledge-gap problem by building a global distribution database and
a website to visualise their results. Since studying all insects would be an insurmountable task, they are focusing on
ants, one of the most abundant and ecologically important group of insects. With 15,000 species described, and
another estimated 10,000-15,000 more species to be described and categorized, ants are ubiquitous and one of the
best studied among insect groups, making them a perfect system to approach this question.
Current progress on their results can now be tracked on antmaps.org (http://antmaps.org/). With just a few clicks,
entomologists can inquire about the distribution of thousands of species, account for the species diversity for any
region of the world, or compare the similarities of different regions with one another.
Tropical and subtropical regions like Hong Kong are not only home for the majority of species on the planet but also
the least studied regions of the world. With the exception of a handful of well-sampled hotspots, most tropical
regions of the world are in urgent need of ant (as well as other insects) exploration. This is especially pressing
considering the small range of many insect species discovered and the increasing pressure of habitat conversion for
urbanization of agriculture. Simply put, if no efforts are made, thousands of species will disappear before we even
had the chance to look at them. By developing a new tool like antmaps.org, the research team aspires to foster
species exploration and increase species description rate.
1
170 ant species recorded in Hong Kong
Locally, the website antmap.org informs us that 170 species and 228 species have been recorded in Hong Kong and
Guangdong province respectively, of which 114 of the species are shared in both regions. Those who take the time to
study ants in detail will be fascinated by their diversity of shapes, sizes, colours or behaviours. Here below are some
examples of Hong Kong species:
Figure 1
Brief overview of some ant species encountered in Hong Kong & Guangdong province
(Photo courtesy: HKU Insect Biodiversity and Biogeography Laboratory)
Species name
Full face head view
Habitat
Colony size
Individual Behaviour
(#individuals) size (mm)
1.1
Gesomyrmex
howardi
Arboreal
unknown
3–5
Very large eyes
door-blocking
soldier
1.2
Acanthomyrmex
species
Grounddwelling
15 – 50
4–6
Collect seed and
mill them
1.3
Leptogenys species
Grounddwelling
25 – 50,000
6 – 12
Specialized
predators of
earthworms, pill
bugs or other
ants
1.4
Carebara species
Subterranean
20 – 250,000
1.4 – 5
Possess a soldier
caste with
exaggerated large
head – size <
2mm
1.5
Trap-jaw ants
(Odontomachus
species)
Grounddwelling
50 – 1000
10 – 16
Open mandibles
to 180° and close
them to capture
prey in 0.0004s
1.6
Mini trap-jaw
ants)
Strumigenys
species)
Subterranean
40 – 300
1.6 – 3.5
Specialized
predators of
small insects and
mites
2
1.7
Pseudolasius
species
Grounddwelling
300 – 500
3–4
Farm other
insects
(mealybugs) to
collect sweet
secretions
(honeydew)
1.8
Dracula ants
(Stigmatomma
species)
Subterranean
10 – 50
2–6
Predators of
centipedes –
Vampire like
behavior with
their larvae
1.9
Discothyrea
species
Subterranean
20 – 100
2–3
Spider eggs
predator
1.10
Cataulacus species
Arboreal
50 – 100
5
Heavy protection
against predators
1.11
Leptanilla sp.
Subterranean
50 – 300
1.2
Very rare –
smallest ant in
Hong Kong
1.12
Foamy ant
(Pseudoneoponera
rufipes)
Grounddwelling
10 – 20
20
Produce foam as
a defensive
strategy
Arboreal
50,000 –
50,0000
12
Subterranean
1,000 –
200,000
3–7
Construct nest by
sewing leaves
together
Capture insects
by raiding them
with thousands of
workers
Other species
1.13 Weaver ant
(Oecophylla
smaragdina)
1.14 Army ants
(Aenictus &
Dorylus species)
3
The species named Pseudoneoponera rufipes produce foam as a defensive mechanism, other species known as army
ants (species of the Dorylus and Aenictus genera) are able to capture prey a hundred times larger than a single
worker, other ant species create complex nest structures the size of a rugby ball by sewing leaves together (the
weaver ant Oecophylla smaragdina) or build tube-like shelters over the “cattle” insects they protect (Crematogaster
species), while another species displays the fastest animal movement known (Odontomachus species) by completely
closing its mandibles in about 0.4 millisecond (0.0004 second). All these natural wonders are happening right here
and many more are waiting to be discovered in Hong Kong and all over the world.
Until a year ago, most of the work realized on ants in Hong Kong was done by Dr. John Fellowes, Honorary
Assistant Professor of HKU Kadoorie Institute, nearly 20 years ago. In the view of this, Guénard’s team members in
HKU’s Insect Biodiversity and Biogeography Laboratory recently started in Hong Kong the ecological and
behavioral exploration of these astonishing creatures with the aim to further enrich the knowledge of biodiversity in
ants in the territory. For less than a year the team has conducted several surveys to gain better knowledge of local ant
fauna and the results are astonishing. While this work is still at its beginning and focuses only on species present in
leaf litter, it has already allowed the identification of 15 newly recorded ant species and potentially a dozen of new
species for science. This represents an increase of 16% of the ant fauna known in the territory and it can be expected
that more will be discovered.
One of the most significant discoveries is the collection of a tiny new species of Leptanillinae (Figure 2), a subfamily
of ants thus far unknown from southeast China, with the closest geographic records for this subfamily reported in
Hunan province and Taiwan. Incredibly, this species was collected in Lung Fu Shan Country Park - just a few
hundred meters from the Laboratory. Another newly recorded ant species from Hong Kong - the dracula ant,
Stigmatomma rothneyi – is shown in Figure 3 below. Indeed, anybody in Hong Kong could find a new insect species
in their backyard or in the park they visit over the weekend.
Figure 2
Two extremes in size within the Hong Kong ant fauna
(Top) A species of the genus
Leptanilla sp. is only 1.2mm
long
(Photo courtesy:
Antweb.org)
(Bottom) The “giant”
Pseudoneoponera rufipes (the
foamy ant) is 20 mm long.
(Photo courtesy:
HKU Insect Biodiversity and
Biogeography Laboratory)
4
Figure 3
The dracula ant, Stigmatomma rothneyi, one of the newly recorded ants from Hong Kong
(head and profile views) (Photo courtesy: HKU Insect Biodiversity and Biogeography Laboratory).
The surveys will also provide important information about the distribution of unwanted, invasive ant species in Hong
Kong. The spread of the fire ants (Solenopsis invicta) or other non-native species is important to monitor, and we are
in critical need of information on their impacts on native fauna and flora of Hong Kong. Most importantly, early
detection of invasive species is vital for efficient control of these populations and prevents further spread. This can
only be achieved through regular monitoring and development of solid baseline knowledge on both native and nonnative species.
The team will extend its study to other parts of China and Asia as well, potentially some of the most diverse regions
in the world. Information gathered will contribute to the continuous update of antmaps.org, while development of
new tools such as high resolution imaging to highlight the diversity and complexity of ants and other insects will
increase accessibility for students and a broader audience.
Figure 4
The team of HKU Insect Biodiversity and Biogeography Laboratory displaying exhibits of ant
species (from the left: PhD student Mr Roger Lee, Assistant Professor Dr Benoit Guénard and Research Assistant
Miss Ying Luo）.
Figure 5
The team of HKU Insect Biodiversity and Biogeography Laboratory introducing the newly launched
antmap website they built up with Okinawa Institute of Sciences and Technology (from the left: PhD student Mr
Roger Lee, Assistant Professor Dr Benoit Guénard and Research Assistant Miss Ying Luo）.
5
Figure 6
Dr Benoit Guénard, Assistant Professor of HKU School of Biological Sciences introducing the
common ants that can be found in Hong Kong.
Figure 7
Assistant Professor Dr Benoit Guénard demonstrating the search of ant species with the antmap.
Figure 8
PhD student Mr Roger Lee elaborating the means collecting ants with winkler extractor.
Antmaps.org: http://antmaps.org/
Images shown above can be downloaded via the following link: http://www.scifac.hku.hk/news/media?page=1
To learn more about the Insect Biodiversity and Biogeography Laboratory and its research, please visit:
http://benoitguenard.wordpress.com/
Media enquiry:
Communication and Public Affairs Office Ms Rhea Leung (phone: 2857 8555/ 9022 7446; email:
[email protected])
Faculty of Science Ms Cindy Chan (phone: 3917 5286/ 6703 0212; email: [email protected])
~ End ~
6