Research Brief no. 5 2005–06
Bogong moths and Parliament House
Bill
McCormick
Science, Technology, Environment and Resources Section
31 October 2005
Contents
Executive summary
Introduction
The Bogong Moth, Agrotis infusa,
a migratory species of moth
Life cycle of the Bogong moth
Breeding
Migration
Camping (Aestivation)
Predators and Parasites
Return Journey
Survival Mechanism
Parliament House as a moth
trap
Managing the moth invasions since 1988
Insecticide bioaccumulation in Bogong moths
Current Measures
Summary
References
Endnotes
Executive
summary
The Bogong moth (Agrotis infusa) is one of the few species of
moth or butterfly which migrates annually to a specific destination and
then returns to the original breeding area six months later. It starts
and finishes its life cycle on the slopes and plains west of the Great
Dividing Range, generally in NSW. The adults migrate to the Southern Alps
(Snowy Mountains) where they spend the hot summer. The Bogong moths use
migration as a means of avoiding the harsh environmental conditions of
their breeding areas thus enabling them to maintain relatively high populations.
The moths migrate to the highest peaks in the Southern Alps where millions
spend the hot summer months aestivating in deep, dark crevices in rock
caves among granite boulders. Predators of the adult moths in and around
the caves include bats, pygmy possums, foxes, Australian ravens and currawongs.
It is not known exactly how Bogong moths navigate on their journey to
and from the mountains. It is the light of the horizon that appears to
play a part in maintaining flight elevation during their night flights,
rather than the stars or the moon. Artificial light may distort the moth’s
view of the horizon, making it fly in a circular pattern around the light.
Canberra is on the flight path of the Bogong moths, and Parliament House
built on Capital Hill with its floodlit flagpole and extensive lighting
acts like a giant light-trap for the moths migrating through the Canberra
area during October and November.
The infrastructure managers of Parliament House have been wrestling with
the Bogong moth problem since the building opened in 1988. The immediate
response in 1988 was to trial turning off the lights. This appeared to
be successful, enabling most of the moths to escape the confines of Parliament
House. The moths that didn’t escape left after-effects that lasted for
months. Dead moths continued to be discovered in offices all over Parliament
House. These carcasses provided a food and breeding source for carpet
beetles and clothes moths.
Bogong moths have been found to transport arsenic from the grazing and
cropping areas in the inland plains of eastern Australia to their resting
sites in the mountains. Higher levels of arsenic were found in the soil
and grasses in the outwash areas of some of the caves where the moths
aestivate over summer, than in the soils and grasses in adjacent areas
without moths.
This paper updates a Parliamentary Library
Background Paper, titled Bogong Moths and the New Parliament House,
issued on 8 November 1988. The information in that paper came primarily
from the studies on the Bogong moth by Dr I.F Common(2).
Community interest in the annual Bogong moth migration has been heightened
in recent years with a moth concentration during October 2005 in Newcastle
and other coastal areas, and of earlier memorable events such as the evening
track and field program and the closing ceremony of the Sydney 2000 Olympics.
Such coastal concentrations of Bogong moths occur when north-west winds
blow them towards the sea from their normal migratory course along the
Great Dividing Range to the Snowy Mountains(3).
Canberra lies on the migration route of Bogong moths from the slopes
and plains of south eastern Queensland and northern New South Wales to
the highest mountains of the ACT and Kosciuszko National Park. Parliament
House receives annual influxes of migratory moths in spring. Since it
was opened in 1988, Parliament House has acted as a beacon which attracts
varying numbers of these migrating moths from year to year.
This paper looks at the biology of the moth, its migratory habits, the
problems experienced at Parliament House when moth numbers build up and
the impact of control measures adopted to date. The paper also discuses
evidence that the migrating moths transport arsenical compounds from the
slopes and plains to their aestivation sites in the mountains.
The Bogong moth, Agrotis infusa, is
a migratory species of moth found in southern Australia. There are six
or more species of the genus Agrotis in Australia and others are
found elsewhere in the world. Only some of these species are migratory.
A. infusa is a common species and is found in New South Wales,
Victoria, Queensland, South Australia and Western Australia. However,
it is not clear whether Western Australian populations are migratory.
The Bogong moth is one of the few species of moth or butterfly which migrates
to a specific destination and then returns to that same destination in
subsequent seasons.
The Bogong moth starts and finishes its life cycle on the slopes and
plains west of the Great Dividing Range, principally in NSW. The adults
migrate to the highest mountains of south eastern Australia where they
spend the hot summer. Figure 1 shows the areas where larvae of the moth
have been recorded. This includes some coastal areas. A small proportion
of the Bogong moth population, however, does not migrate but instead remains
on the slopes and plains west of the Great Dividing Range. These individuals
tend to be smaller and have white hind wings.
In April and May, adult moths lay eggs in the fields of the western slopes
and plains of New South Wales, Victoria and southern Queensland. These
eggs hatch into caterpillars commonly referred to as cutworms because,
rather than biting out sections of leaf, they fell seedlings and herbaceous
stems by cutting through them and feed just under the soil surface on
the felled plants(4). These caterpillars are pale with brown
head capsules, but turn green after starting to feed and may then turn
brown if numerous.
The caterpillars feed at night, mainly on broad-leafed weeds and pasture
plants. They do not appear to feed on grasses except where other foliage
is unavailable. However, they have been known to damage young wheat. Outbreaks
of the caterpillars may occasionally cause some minor crop or pasture
damage. The caterpillars grow and moult(5) five times over
the winter period. Their development is relatively slow due to the low
temperatures in winter. The caterpillars pupate in late September or October,
and after a short period emerge as adults. The adults feed on nectar from
flowers and are active at night.
Some of the adults, which have emerged and started feeding, develop sexual
organs, mate and lay eggs. This segment of the population stays in the
breeding area to continue its life cycle. If there is sufficient food
available there may be three generations of moths completed over the hotter
months from October until April. Since the Bogong moth larvae feed on
broad leaf plants, the food supply reduces with the onset of hotter weather
when grass growth begins to dominate the pastures. Therefore, only a small
proportion of the winter moth population can be supported in these areas
over summer.
The bulk of the Bogong moth population does not develop sexual organs
but instead departs the pastures and migrates in mass night flights.
It is not known exactly how they navigate on their journey to and from
the mountains. However, light sources appear to play a part in maintaining
flight elevation(6). Moths migrate and fly actively under cloudy
conditions and during a new moon. It is unlikely that the old theory,
that moths are attracted to artificial light because they mistake it for
a natural light like the moon or stars, is correct(7).
While moths may not be navigating by the moon or stars, it is yet to
be demonstrated what other factors are important. Moths orient and maintain
elevation at night by light, but it is probably by the light at the horizon
and not by the stars or the moon since, given their ability to see polarised
light, they probably can make out the horizon in cloudy conditions. This
mechanism may allow them to maintain level flight over long distances.
It is likely that the disruption of this orientation for flight that causes
artificial lights to attract moths(8). An artificial point
source of light may distort the moth’s view of the horizon, making it
fly in a circular pattern around the light.
Unlike insects such as bush flies and other moths which are simply dispersed
by the winds, the Bogong moths fly strongly towards the Southern Alps
around October. Strong winds can blow them off course as happened in October
1988, during the September 2000 Olympics and in October 2005 when large
numbers were blown into Sydney. They have even been found in New
Zealand, having been blown across the Tasman Sea by strong westerly winds.
However, since moths fly at low altitudes and at night when the winds
are generally light, and rest during the day, significant numbers will
remain on course and reach their correct destination.
Bogong moths require large amounts of energy to make their migration
flights and to survive over summer. Much of the moths’ energy comes from
large fat reserves stored in their abdomens (up to 60 per cent of dry
body weight). Much of this fat is laid down during food intake by the
larvae, but the adult moths can also feed on nectar. The fat reserves
are sufficient to carry the moths through their migration without feeding
and it appears that some moths may indeed not feed during this time. Since
nectar feeding can start reproductive development in some moths it is
probable there is some genetically determined characteristic which prevents
such sexual development until after the migrating moths start returning
from the mountains to their place of origin in autumn. Some individuals
do become sexually mature, mate and lay eggs en route.
The moths migrate to the highest peaks in the Southern Alps where they
spend the hot summer months. The moths arrive at these areas and seek
out deep, dark crevices in rock caves among granite boulders, in the extensive
Kosciuszko Batholith for example, where the temperature and humidity are
fairly constant. Here the moths congregate in their millions and aestivate(9)
(remain dormant) over three or four months of summer. They group together
in the rock piles in large aggregations. This behaviour may be a mechanism
to reduce moisture loss. The suitable sites where the moths aggregate
are revisited year after year and are referred to as permanent camps.
Some moths do not remain motionless all summer but become active for a
brief period after dusk, before settling for the night in the camps.
Predators of the adult moths in and around the caves include bats, pygmy
possums, foxes, Australian ravens and currawongs. There is also a parasitic
nematode (worm) which attacks adult moths in the caves.
The aestivating moths have some protection against the hunting bats.
Moths have tympani (or ear drums) on their thorax (middle segment) which
enables them to hear the echo location emissions from bats that prey on
them when they venture into the open for brief evening flights from their
summer camps. When they hear sharp sounds made by the bats in flight they
are alerted to take evasive action.
In the past, aborigines of the hinterland areas travelled to the high
mountains to exploit Bogong moths as a food source in late spring or early
summer. They collected aggregating moths from the caves and rock shelters
in the mountains. The moths were either singed in a fire to remove wings
and scales and eaten immediately or ground into a paste and cooked into
cakes which could be transported back to their camps.(10)
From February through to April, moths leave the caves and start to return
to the western slopes and plains (see figure 2). This migration is not
as dense as the spring event because the moths don’t leave en masse and
because their numbers have been considerably reduced through the losses
on the trip to the summer quarters and the predation and parasitism at
their resting places. The mountains of the ACT become staging posts in
autumn for migrating moths moving from mountains further south. From here,
they travel in a span of directions between west and north-north east.
The adult moths don’t necessarily return to exactly the same place from
where they emerged, but fly back to areas suitable for egg laying.
They travel at night and rest during the day. They feed on nectar and
it is this diet, after the moths’ summer aestivation period, that starts
the development of their reproductive systems. The moths mate and eggs
are laid in the slopes and plains of New South Wales and the Darling Downs
of Queensland. The timing of the maturation of the eggs and hatching of
larvae to coincide with the autumn emergence of broad-leafed pasture plants.
This is the start of the next generation (see figure 3).
The Bogong moth uses migration as a strategy of avoiding unfavourable
environmental conditions in order to maintain relatively high populations.
Other moths may pupate underground in the soil as a means of avoiding
high summer temperatures.
As noted above, the numbers of Bogong moths that stay on the slopes and
plains are far fewer than the migrating population. The sparse summer
pastures can support far smaller populations of Bogong moth larvae than
the winter pastures. In summer, grasses which are not palatable to moth
larvae, dominate, whereas broad-leaf pasture plants take over in winter.
In favourable habitats with adequate food, three to four generations of
Bogong moths are possible annually but for the great majority of Bogong
moths, the migratory population represents the one and only generation
each year.
Canberra is on the flight path of the Bogong moths travelling to the
high peaks of the Brindabella Mountains, such as Mt Gingera, and further
south. Parliament House, built on Capital Hill with its elevated floodlit
flagpole and extensive lighting, appears to disrupt the flight of moths
migrating through the Canberra area. It acts like a giant light trap.
Starting in early October, the Bogong months start congregating around
Parliament House, treating it as temporary camp on their way to the mountains.
When the powerful lights are illuminated continuously during the night,
the moths are not able to fly away. Over the weeks, the warmer weather
brings larger numbers of Bogong moths through Canberra, joining those
attracted earlier. The moths attracted to Parliament House may mass in
the nooks and overhangs of windows and courtyards to avoid the light and
heat of the day in somewhat the same manner that they naturally aggregate
in rock shelters of the mountains.
In October each year the sun, heat and noise of Parliament House keep
the moths agitated and moving around the building. The moths that come
into Parliament House enter through open doors. These moths cannot find
their way out and die.
In 1988, moths entered the air conditioning ducts via the mesh covering
the air intakes because the mesh size of the screen was too coarse. This
problem was later remedied by changing to a smaller size mesh on the air
intakes of the air conditioning systems.
The question has been asked whether the moths on the outside of the building
eventually leave or stay for the summer, deciding that Parliament House
is as good a camp as the granite tors in the Brindabellas and the Snowy
Mountains? While it appears that some moths have settled in to the building
for good, CSIRO scientists have suggested that they are merely making
a temporary camp. It is the lights being left on all night that is preventing
the moths leaving. If the lights were to be extinguished over several
nights most of the moths would continue their migration(11).
The CSIRO scientists believe that the moths would move on even without
the lights being turned off, but that this would take more time(12).
The infrastructure managers of Parliament House have been wrestling with
the Bogong moth problem since the building opened in 1988. The immediate
response in 1988 was to trial turning off the lights. Turning off the
lights on the nights of November 3 and 4 1988 appeared to be successful.
It enabled most of the moths to escape the confines of Parliament House.
This was possibly assisted by the warm night temperature and a weather
change that had passed through Canberra in the late afternoon, during
the trial period.
The after-effects of dead moths were noticeable, however, for months
following their first arrival in 1988. Dead moths continued to be discovered
in offices all over Parliament House. Their carcases amounted to a food
and breeding source for carpet beetles and clothes moths. A clothes moth
infestation occurred as a result of them breeding in the carcasses of
Bogong moth, resulting in significant damage to fabric in the House of
Representatives(13). In response, the then Joint House Department
commenced spraying appropriate areas of Parliament House with an insecticide.
The residual synthetic pyrethroid insecticide deltamethrin, known by the
brand name Cislin 10, was used to discourage the moths from clustering
in the crevices of the Parliament House building.
Some changes to minimise the attractiveness of Parliament House to Bogong
moths included placing mesh over the air conditioning inlets to physically
prevent entry and turning off lights in the windows of Parliament House
after 11 PM. Initially the equipment necessary to turn off the window
pelmet lights had not been installed. The then President of the Senate,
in an answer to a question, said that connection of lighting relays had
commenced in the week of 20 December 1988 to enable the window pelmet
lighting and external lighting to be turned off during daylight hours
[sic](14).
In Senate Estimates of 3 October 1989 the then Joint House Department
outlined its program to reduce the attractiveness of new Parliament House
to Bogongs:
We have a program in place to try to alleviate the attraction
of this building to the Bogong moth, which is currently flying over
Canberra. The program mainly involves control of the external lights
to the building, which are the ones which we believe are attracting
the moth-the flagpole light, the curved wall lighting and the lighting
on the sloping walls in the forecourt. We are turning those off certainly
from midnight to dawn and we also have a program to lessen the impact
of the internal lights. We are turning off the pelmet lighting, which
can be done by the building monitoring system under block control, and
we are asking cleaners and attendants to close all the blinds so that
where people are working at night with the lights on it is not as bright
from the outside. (15)
However these steps may not have been implemented routinely during the
next spring since the Bogong moths returned to Parliament House in numbers
in 1990. On 16 October 1990 the then Acting Speaker made the statement:
For the information of honourable members, I have received
questions from members concerning Bogong moths. I advise
that the Joint House Department has undertaken the following action
in an effort to control the presence of Bogong moths
in the building and to reduce the attraction of the building itself
to moths: Firstly, pelmet lighting in offices in both
the Senate and the House of Representatives will be turned off as from
this evening. Secondly, two of the four flagpole lights have been turned
off. Thirdly, attendants have been asked to turn off all unnecessary
office and suite lighting. Fourthly, a great number of external lights
have been turned off, including ramp lights, lighting around the tennis
courts, and in the formal gardens. Courtyard lighting will also be reduced.
The engineering services section has discussed with the
Australian Capital Territory authorities, road safety authorities and
the Parliament House security controller the feasibility of turning
off all or some of the street lights located on Parliament Drive. A
fine mesh has been installed over external air intake and exhaust vents,
and windows have been sealed to deny moths entry.
Finally, an information circular is being issued today
requesting occupants of the building to turn off lights in their offices
and suites as they leave and not to leave doors to courtyard areas open
during the day and evening as this has been a major avenue for entry
for the Bogong moths. Housekeeping and cleaning staff maintain a continual program
of cleaning out rooms, suites, corridors, et cetera, which have been
infested with the moths. I assure the House that every action is being taken to contain
Bogong moth infestations.(16)
The unintended side effect of these measures was a saving in electricity
use. On the 4 December 1990 the President of the Senate made the statement
On 16 October 1990, Senator Coulter asked me, in relation
to the recent Bogong moth infestation, that a measure of the savings
in electricity as a consequence of turning off the lights be made and
that that be reported back to the Senate. The Joint House Department
has advised me that the reduced lighting levels have saved an estimated
$365 a week or $19,000 per annum in energy costs. Since moving to the
new Parliament House, the Joint House Department has achieved a 10 per
cent saving in energy costs. A comprehensive energy audit is presently
being undertaken. Its recommendations will lead to further savings in
energy costs. Senator Coulter's request to reduce the use of lights
is being taken into account by the energy auditors.(17)
Bogong moths have continued to appear annually in varying numbers in
Parliament House during October and November. The fluctuations in numbers
are due to a variety of factors including:
- the impact of winds on the flight path;
- the numbers of larvae emerging and growing to adulthood in the slopes
and plains of New South Wales; and
- size of the light sources in the ACT region that may attract moths
and cause them to divert from their flight path.
The 1988 background paper made the following comment.
It should be remembered that New Parliament House will
remain a wonderful beacon to attract the spring migrations of Bogong
moths for the next 200 years.
A paper published in 2001, indicated that the Bogong moths transported
arsenic from the grazing and cropping areas of the inland plains of eastern
Australia, where the larvae are found, to the aestivation sites in the
mountains.(18) Higher levels of arsenic were found in the soil
and grasses in the outwash areas of those caves where the moths aestivate
over summer, than in the soils and grasses in adjacent areas without moths.
The higher levels of arsenic in the outwash areas resulted in the death
of the grasses. The elevated arsenic levels were also noted in the faeces
of mammals that predate on the moths. Mountain pygmy possums, an endangered
species found in the snow fields of the Kosciuszko National Park, had
higher levels of arsenic as well, indicating that the moths may be the
source of the arsenic in this area. The paper identified the probable
source of the arsenic to be from the past use of arsenic by agriculture,
in pesticides and in cattle and sheep dips in the breeding areas. An arsenic
based insecticide is still licensed for use as a herbicide in New South
Wales, in the form of monosodium methylarsonate (MSMA). Currently, MSMA
is used as a post-emergent herbicide for cotton, where the moth larvae
attacks emergent seedlings. It is unclear whether such herbicides may
be the source of the high levels of arsenic in the moths from the South
Ramshead caves or whether earlier uses of arsenical compounds have caused
arsenic to accumulate in the soil. The study noted that Ramshead cave
soils in the mountains above Thredbo had far higher arsenic levels than
those moth sites in Mt Gingera in the ACT or Mt Buller and Mt Buffalo
in Victoria. These site specific variations in arsenic levels would be
consistent with Bogong moths in different aestivation sites coming from
different areas. This hypothesis has yet to be resolved by genetic studies.
In October 2003, 14 dead currawongs (birds similar in size to magpies)
were found in Parliament House gardens. Concerns were raised at the time
that the cause of death could be related to high levels of arsenic in
Bogong moths. Concerns were also raised at the time that the birds died
by eating Bogong moths killed by the residual insecticide, Cislin 10 which
had been sprayed to control ants, spiders and moths. Several bird carcasses
were sent for autopsy but the results were inconclusive.
There is no specific evidence to support either theory as the possible
cause of the currawong deaths.(19)
It was stated in the Department of Parliamentary Services 2003–04 Annual
Report that Cislin 10 had been used for several years without bird deaths
being recorded and that it was used to discourage the moths. The Estimates
Committee was told that spider control, not moth control, was the prime
purpose for using Cislin 10(20). There was confusion whether
the Cislin 10 was used to kill the Bogong moths or to stop them dying
in Parliament House and forming a food source for clothes moths.
Estimates Committee Hansard of 3 November 2003 quoted Mr Bolton of the
then Joint House Department (JHD) saying that it sprayed once a year in
early spring, not particularly for Bogong moths, but that the spray had
had an effect on them.
It is a regime that is used—and it is used in a lot of
Canberra—in the early spring to control spiders and a lot of other things,
but it also does allow us to do some control on the moths. It is very
important that it is only one aspect of moth control. Over the years
all the air conditioning vents that come into the building have had
a lot of stainless steel fine mesh put in place. As the President has
advised Senator Lees in writing, to control the moths we presently use
cleaners for about a month. I think it is six cleaners who work eight
hours a day for virtually three to four weeks, trying to vacuum up these
moths over this period of time, depending on how big the incursion is
in the air. We also have at different times changed the lighting on
the building to try and restrict the number of moths that come here.
It is more difficult when the house is sitting, obviously, to do that
than it is when the house is not sitting. You can turn off a whole lot
more lights when it is not. So there is a whole series of things, and
spraying is just one element.(21)
Mr Bolton said that if the then JHD did not deal with the Bogong moths
in some way then they would have further pest control problems such as
carpet beetle outbreaks which use the moth carcasses to live and breed
in. He stated that Cislin 10 had a low toxicity for mammals and he did
not believe that it posed any hazard to humans when sprayed as per the
manufacturers instructions at the very dilute rate used to control insects.
He said that Cislin 10 sprayed on porous surfaces of Parliament House
would have a residual half life of about 20 days.
As a result of the death of the currawongs the Senate passed a motion
moved by the then Senator Meg Lees:
That the Senate—
(a) notes:
(i) the death of at least 14 currawongs around Parliament
House during the last 2 weeks of October 2003, and the subsequent
absence of most magpies and currawongs
(ii) that the likely cause of the bird deaths is
their consumption of contaminated Bogong moths
(iii) that the contamination of the Bogong moths
is most likely due to the application of Cislin, a pyrethrum-based
spray, around Parliament House, to kill Bogong moths, and
(iv) that the data sheet prepared by the manufacturers
of Cislin notes that it is highly toxic to fish, aquatic organisms
and bees and also toxic for birds in various concentrations, and
(b) asks that the Joint House Department cease any
further spraying of Cislin, or other substances toxic to birds, in any
concentration, in 2003 or in future years.(22)
On 7 October 2005, Hilary Penfold QC, the Secretary of the Department
of Parliamentary Services issued an Information circular outlining measures
to be taken in response to the Bogong moth migration.
2. During the next two months we can expect many Bogong
moths to divert from their migration path and find their way to Parliament
House. It is suspected that they are attracted by bright lights. External
lighting levels around the building have been reduced to about half
of normal capacity so that fewer moths are attracted to the building.
3. The moths usually congregate in caves over summer,
and therefore seek out cool places around the building where they can
mimic this behaviour. Many moths eventually find their way into the
building through open doors and through various building crevices.
4. In the past an application of insecticide, Cislin
10, was used to control the moth. However, we have not used insecticides
for moth control since September 2003. This means that building occupants
have a bigger role to play in controlling the moths.
5. You can help by:
(a) turning off the lights in your rooms when you
leave (this also helps save energy and reduces greenhouse gas emissions)
(b) closing the doors that open to courtyards
(c) advising the Building Management Help Desk (extn
5045) if you notice where Bogong moths are gaining entry to the building.(23)
The almost two decades of history of Bogong moth invasion of Parliament
House, a natural phenomenon, suggests that low cost, non-intrusive measures
to prevent the problem will not be successful. Mitigatory action (closing
doors, turning off lights and vacuuming up the dead moths) appears to
be the appropriate response.
In 2005 Bogong moths started arriving at Parliament House in numbers
at the end of September and had mostly departed by the middle of October,
after supplying the local magpies and currawongs, and their young, with
a substantial food supply.
Common, I.F.B 1954. A study of the ecology of the adult Bogong moth,
Agrotis infusa (Boisd.) (Lepidoptera: Nocturidae) with special
reference to ts behaviour during migration and aestivation. Australian
Journal of Zoology, vol.2 (2) pp.223–263.
Flood, J. 1980. The Moth Hunters. Aboriginal Prehistory of the Australian
Alps, Australian Institute of Aboriginal Studies, Canberra.
Hughes, R.D. 1975. Living Insects, he Australian Naturalist Library,
Collins, Sydney.
- Cessation or slowing of activity during the summer; especially slowing
of metabolism in some animals during a hot or dry period.
- F. B. Common, A study of the ecology of the adult Bogong moth, Agrotis
infusa (Boisd.) (Lepidoptera: Nocturidae) with special reference to
its behaviour during migration and aestivation, Australian Journal of
Zoology, 1954, vol. 2 (2), pp. 223–263.
- R. Macey, Shedding light on a fleeting fast of fluttery, The Sydney
Morning Herald, 5 October 2005.
- Dr Ted Edwards, personal communication.
- Shedding the insect’s exoskeleton so it can grow in size.
- ibid.
- ibid.
- ibid.
- Cessation or slowing of activity during the summer; especially slowing
of metabolism in some animals during a hot or dry period.
- J. Flood, The Moth Hunters, Aboriginal Prehistory of the Australian
Alps, Australian Institute of Aboriginal Studies, Canberra, 1980.
- The Hon. K. Sibraa, Adjournment: Greenhouse Effect–Bogong Moths Senate
Hansard 3 November 1988, p. 1977.
- The Hon. K. Sibraa, Question Without Notice: Bogong Moths Senate Hansard
2 November 1988, p. 1801.
- Hood, Senate Estimates Committee Parliament Division 107 Joint House
Department 3 October 1989, pp. 145–.
- The Hon. K. Sibraa, Question Without Notice: Parliament House: Energy
Consumption Senate Hansard, 21 December 1988, p. 4771.
- Hood, Senate Estimates Committee Parliament Division 107 Joint House
Department 3 October 1989, pp. 145–.
- The Hon. G. G. D. Scholes, Procedural Text House of Representatives
Hansard, 16 October 1990, p. 2926.
- The Hon. K. Sibraa, Question Without Notice: Bogong Moths Senate Hansard,
4 December 1990, p. 4880.
- K. Green, L. Broome, D. Heinze, and S. Johnston, Long distance transport
of arsenic by migrating bogong moths from agricultural lowlands to mountain
ecosystems, The Victorian Naturalist, 2001, vol. 118(4), pp.
112–116.
- http://www.aph.gov.au/dps/building/EMS/Publications/Ecologically_Sustainability_Development_31_Dec_03.htm
- M. Bolton, Estimates Committee Finance and Public Administration Committee
Parliament: Joint House Department, 3 November 2003, p. 118.
- ibid.
- Senate Hansard, Parliament House: Currawongs Senate Hansard 24 November
2003, p. 17527.
- H. Penfold, Bogong Moths, Information Circular 2005/21, Department
of Parliamentary Services, 2005.
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