Cat`s claw creeper Macfadyena unguis-cati

Transcription

Cat`s claw creeper Macfadyena unguis-cati
Macfadyena unguis-cati (L.)
A.H.Gentry – cat’s claw creeper
K Dhileepan
ABSTRACT
Cat’s claw creeper Macfadyena unguis-cati (Bignoniaceae), a perennial woody climbing vine native to tropical
America, is a major environmental weed in Qld and
NSW, Australia. Biological control of cat’s claw creeper
was initiated in South Africa in 1996, then in Australia in
2001. Surveys in the native range have identified nine
insects, of which six have been prioritised. So far, Charidotis auroguttata, Carvalhotingis visenda, Carvalhotingis
hollandi, Hypocosmia pyrochroma and Hylaeogena
jureceki have been imported into Australia for host-specificity tests. The leaf-feeding beetle C. auroguttata was not
approved for field release due to perceived risk to a native
non-target plant. One leaf-feeding tingid, C. hollandi,
could not be established in quarantine. The second leaffeeding tingid, C. visenda and the leaf-tying moth
H. pyrochroma were approved for field release in 2007.
The tingid has become widely established, but its rate of
spread remains very low. There are early indications of
the field establishment of the leaf-tying moth. The leaffeeding jewel beetle H. jureceki was imported to Australia
in 2009 for host-specificity testing. Though specialist
leaf-feeding herbivores could be effective in reducing the
existing tuber bank, they may have only limited impact
on weed spread arising from seed production. Hence
future biological control efforts should focus on reducing
seed output by using the specialist pod- and seed-feeding
weevil Apteromechus notatus from Brazil.
Key words: Charidotis auroguttata, Carvalhotingis
visenda, Carvalhotingis hollandi, Hypocosmia pyrochroma,
Hylaeogena jureceki, Apteromechus notatus, Qld, NSW,
South Africa, Argentina, Paraguay, Brazil.
INTRODUCTION
Cat’s claw creeper, Macfadyena unguis-cati (L.) Gentry
(Bignoniaceae), is a perennial woody climbing vine that is
native from Mexico through Central America to tropical
South America, including Trinidad and Tobago (Rafter et
al. 2008). Introduced as an ornamental, the vine became
naturalised in several countries in Asia (China, India,
Malaysia, Nepal, Sri Lanka and Thailand), Australasia
and the South Pacific (Australia, New Zealand, Indonesia, Micronesia, New Caledonia, Hawaii and Cook
Islands), Europe (Sicily, Switzerland, Serbia and Montenegro, France and Greece), Africa (Kenya, Mauritius,
South Africa, Uganda and Zimbabwe) and North America (southern USA). Cat’s claw creeper is now regarded as
invasive in Australia, South Africa, India, Mauritius,
China, Hawaii and Florida in the USA, New Caledonia, St
Helena Island and NZ (King and Dhileepan 2009).
Cat’s claw creeper is a high climbing woody vine (Fig.
1), with stems up to 6 cm in diameter and roots becoming
elongated and tuberous with age. Upright branches and
horizontal runners can develop adventitious roots. Leaves
are opposite, compound, with two leaflets and a terminal
© CSIRO 2012
Published by CSIRO Publishing, http://www.publish.csiro.au/
091102 Biological Control of Weeds in Aust 4pp.indd 351
19/12/11 21:06:57757
352
Biological Control of Weeds in Australia
Figure 1: Cat’s claw creeper, Macfadyena unguis-cati. a) Stem. b) Leaf and flower. Photos: M Shortus, Qld Government.
three-forked claw-like tendril that enables the plant to
attach itself to tree trunks, other vegetation and artificial
structures such as fences. Flowers are yellow and trumpet-shaped, solitary or in small clusters at leaf axils (Fig.
1). The fruit is a linear flat capsule, to 50 cm long, with
oblong winged seeds. In Australia, the plant usually has a
single annual pulse of flowering in late spring or early
summer. The plant can be propagated from seed, and
vegetatively from below-ground tubers. Stems trailing
along the ground are capable of producing roots at the
nodes. Seeds are dispersed by wind and water and the
seeds do not remain viable more than a year, suggesting
that although the mechanism of spread is through seeds,
the mechanism of persistence is through the tuber bank
(Osunkoya et al. 2009; Vivian-Smith and Panetta 2004).
In Australia, cat’s claw creeper is a major environmental weed (Fig. 2) in Qld and NSW and it has the potential
to spread throughout eastern Australia (Fig. 3). In Qld
and north-eastern NSW, cat’s claw creeper is a declared
noxious weed. Cat’s claw creeper poses a significant
threat to biodiversity in riparian areas, rainforest communities, non-agricultural areas and remnant natural
vegetation (Vivian-Smith and Panetta 2004; Downey and
Turnbull 2007). In densely infested areas, cat’s claw
creeper covers standing vegetation, including shrubs and
large trees up to 30 m tall (Fig. 2), eventually causing
canopy collapse (Sparks 1999). In areas without standing
vegetation or man-made structures, the vines grow along
the forest floor and form dense mats.
The management objectives for cat’s claw creeper are
focused on reducing the rate of shoot growth to limit the
vine’s ability to climb and smother native vegetation, as
well as reducing tuber biomass. The inaccessibility of root
tubers and their ability to regenerate are a major problem
for the control of this weed. Chemical control options for
managing cat’s claw creeper are available, but are often
not used due to the sensitive ecosystems in which it
occurs. Mechanical control of above-ground growth provides only temporary relief, as regeneration from subterranean tubers continues over many years. As a result,
there is a need to treat infested areas with mechanical or
chemical control options repeatedly. This severely limits
the size of areas that can be treated. Susceptibility of cat’s
claw creeper to herbivory (Raghu and Dhileepan 2005;
Raghu et al. 2006; St Pierre 2007) suggests that biological
control is the most desirable option to manage this weed.
BIOLOGICAL CONTROL HISTORY
The biological control of M. unguis-cati was initiated in
South Africa in 1996 by the Agricultural Research Council – Plant Protection Research Institute (ARC-PPRI)
(Sparks 1999). Since then, five insects have been screened
Figure 2: Macfadyena unguis-cati infestation in Qld. Photo:
M Treviño, Qld Government.
© CSIRO 2012
Published by CSIRO Publishing, http://www.publish.csiro.au/
091102 Biological Control of Weeds in Aust 4pp.indd 352
19/12/11 21:06:58430
353
Macfadyena unguis-cati (L.) A.H.Gentry – cat’s claw creeper
Figure 3: Current and potential distribution of Macfadyena unguis-cati in Australia, based on native range distribution (Rafter et al.
2008).
and three approved for field release (King and Dhileepan
2009; King et al. 2011). The leaf-feeding chrysomelid
Charidotis auroguttata (Boheman) was the first agent
released in South Africa in 1999 (Williams 2002), but its
establishment was slow and it failed to survive at several
localities. Subsequently, two leaf-feeding tingids Carvalhotingis visenda (Drake & Hambleton) and C. hollandi
(Drake), a leaf-tying pyralid moth Hypocosmia pyrochroma Jones and a leaf-mining buprestid beetle Hylaeogena jureceki (Obenberger) have been screened (Williams
et al. 2008). C. visenda and H. jureceki have been approved
for field release in South Africa, and both agents are
showing signs of field establishment (King and Dhileepan
2009; King et al. 2011). Biological control of cat’s claw
creeper in Australia commenced in 2001, in collaboration
with ARC-PPRI in South Africa.
PLANT TAXONOMY
M. unguis-cati displays wide genetic diversity throughout
its native range (Sigg et al. 2006; Prentis et al. 2009). In
contrast, the genetic diversity in its introduced range is
very low (Sigg et al. 2006; Prentis et al. 2009). Cat’s claw
creeper populations in most of the introduced ranges,
including Australia and South Africa, appear to have originated from Paraguay and are closely genetically related to
populations within the Paraguay–Bolivia–Argentina
region, representing the southern portion of the species’
native range (Sigg et al. 2006).
In Australia, two morphologically and genetically distinct populations of M. unguis-cati occur (Sigg et al. 2006;
Shortus and Dhileepan 2011). The more invasive shortpod variety is widespread through Qld and NSW, with a
second long-pod variety restricted to a few sites in southeastern Qld (Shortus and Dhileepan 2011). Both varieties
have a yellow trumpet-shaped flower, but the flower of the
long-pod variety has a deeper hue of yellow than the shortpod flower. The pods of the short-pod variety mature in
late summer to early autumn and the pods of the long-pod
variety mature in late winter to early spring. The long-pod
variety has significantly larger leaves, larger seed pods and
more seeds per pod than the short-pod variety. The shortpod variety has a slightly wider seed pod and thicker
leaves than the long-pod variety. Herbarium records at the
© CSIRO 2012
Published by CSIRO Publishing, http://www.publish.csiro.au/
091102 Biological Control of Weeds in Aust 4pp.indd 353
19/12/11 21:06:58675
354
Biological Control of Weeds in Australia
Missouri Botanical Gardens suggest that, in the native
range, the long-pod variety occurs in Colombia, Costa
Rica, Mexico and Nicaragua. The long-pod variety has
also been observed in Brazil (S Neser, pers. comm. 2009).
Only the short-pod variety appears to be present in most
countries in the introduced range (Sigg et al. 2006), except
in Hawaii where the herbarium records suggest that the
population is the long-pod variety.
EXPLORATION
Cat’s claw creeper is endemic from Mexico through Central America and the Caribbean islands to tropical South
America as far south as Chile (Sparks 1999; Rafter et al.
2008). Surveys were conducted in Brazil, Argentina, Paraguay, Venezuela and Trinidad in 1996, and in Paraguay
and Brazil in 2002 by Stefan Neser of ARC-PPRI, resulting in the identification of around nine insect species as
potential biological control agents.
Based on the climatic similarity (using the CLIMEX
model) of locations with cat’s claw creeper infestations in
the introduced range of Australia and South Africa to
those in the native range, the areas of central and eastern
Argentina, south Brazil, Uruguay and parts of Bolivia and
Paraguay were prioritised for exploration for new biological control agents (Rafter et al. 2008). Accordingly, further
surveys were conducted in northern Paraguay and southern Brazil by S Neser in 2009, and previously tested agents
including C. visenda, H. pyrochroma and a seed-feeding
weevil Apteromechus notatus (Hustache) were re-collected
from climatically suitable areas to enrich the existing colonies of these insects in South Africa and Australia.
CANDIDATES
Natural enemies
There is no major insect damage or disease evident on
M. unguis-cati in Australia (K Dhileepan, unpub. data).
Of the nine insects identified as potential biological control agents in the native range, a leaf-feeding tortoise
beetle C. auroguttata, two leaf-feeding tingids C. visenda
and C. hollandi, a leaf-tying moth H. pyrochroma, a leafmining jewel beetle H. jureceki and a seed-feeding weevil
A. notatus have been prioritised for detailed host-specificity testing in quarantine in South Africa and Australia
(King and Dhileepan 2009; King et al. 2011). A rust fungus Uropyxis rickiana Magnus, inducing stem-galls and
leaf-spots on cat’s claw creeper, has been recorded from
Argentina and Brazil (Hernandez and Hennen 2003; S
Neser, pers. comm. 2009), but its potential as a biological
control agent is yet to be ascertained. Other potential
agents recorded in the native range, but yet to be identified, include a shoot-tip feeding sawfly from Brazil, a sapfeeding leaf-hopper from Argentina, Brazil and Paraguay,
a shoot-galling midge from Brazil and Paraguay and a
shoot-feeding mirid bug from Brazil (Sparks 1999).
Agent prioritisation
Insect herbivores from a range of feeding guilds (leaf,
shoot and seed), but not subterranean tubers and roots,
have been recorded on M. unguis-cati in its native range
(Sparks 1999; Raghu et al. 2006). Since cat’s claw creeper
is a structural parasite, biological control agents for the
liana will need to target its climbing habit. Examining the
response of cat’s claw creeper to different types of simulated herbivory can help to identify the type of damage to
which cat’s claw creeper is most vulnerable, so that specialist herbivores likely to cause such damage can be prioritised. Simulated herbivory experiments have shown
that defoliation on its own or in combination with shoot
damage has the potential to significantly reduce cat’s claw
creeper growth. Defoliation also reduced the climbing
habit of the vine and reduced the rate of subterranean
tuber biomass accumulation (Raghu et al. 2006). Simulated herbivory studies indicated that repeated defoliations, a minimum of three defoliation events under shade
and more than three defoliation events under full sun, are
required to stop foliar and tuber growth (St Pierre 2007).
In contrast, below-ground damage needs to be avoided, as
the plant either tolerates or vigorously compensates for
such damage. Specialist herbivores in the leaf-feeding
guild have therefore been prioritised as potential biological control agents of this species (Raghu et al. 2006). In
M. unguis-cati, new recruitment is primarily from seeds,
hence future biological control efforts need to focus on
introducing specialist seed- and pod-feeding insects to
reduce seed output, thereby limiting the future tuber
bank (Osunkoya et al. 2009).
Agents not released
Charidotis auroguttata (Boheman) (Chrysomelidae).
This golden-spotted tortoise beetle has a wide geographic
native range that includes Argentina, Brazil, Paraguay,
Trinidad and Venezuela (Sparks 1999), and was first collected near Las Caracas, Venezuela (Sparks 1999; Williams 2002). It was the first biological control agent for
M. unguis-cati imported from South Africa to Australia,
in 2001 (Dhileepan et al. 2005).
© CSIRO 2012
Published by CSIRO Publishing, http://www.publish.csiro.au/
091102 Biological Control of Weeds in Aust 4pp.indd 354
19/12/11 21:06:58811
355
Macfadyena unguis-cati (L.) A.H.Gentry – cat’s claw creeper
The adults are small, 3–5 mm long and wide, and lay
eggs singly on both surfaces of the leaves and on the
stems. Eggs hatch after nine to 11 days and the larvae feed
on both young and old leaves for 21–25 days, passing
through five instars. Late fifth instars undergo a nonfeeding prepupal period of one to three days, then pupate
attached to the lower leaves or on leaf litter around the
stem. The adults emerge after eight to 10 days and at first
are pale red, turning reddish brown with gold spots after
a further five to seven days. The females lay one to three
eggs per day, of which ~87% hatch. The short generation
time allows several generations per year (Sparks 1999;
Williams 2002). Adults are long-lived, and an adult lifespan in excess of one year has been recorded. Both adults
and larvae feed on the leaves and cause premature leaf
abscission and shoot dieback (Sparks 1999).
Host-specificity tests confirmed that C. auroguttata
was specific to cat’s claw creeper (Sparks 1999; Williams
2002). The agent was released in South Africa (Sparks
1999; Williams 2002) and has become established in
some release sites there (King and Dhileepan 2009).
However, in no-choice trials in Australia approximately
12% of larvae completed development in 59.4 ± 5.2 days
on Myoporum boninense australe Chinnock (Myoporaceae), a non-target native plant, as against 95% larval
development in 35.2 ± 0.43 days on M. unguis-cati (Dhileepan et al. 2005). In the no-choice demography trials,
adults laid eggs from the second week after emergence on
cat’s claw creeper, with an average of 0.286 eggs/female/
day, resulting in an 18-fold increase in the adult population over 16 weeks. Adult survival on M. boninense australe remained high, but oviposition commenced only
from the 10th week after emergence, with an average of
0.023 eggs/female/day, and none of the eggs hatched. In
the choice demography trials, oviposition on M. unguiscati was evident from the fourth week onwards, while on
the non-target M. boninense australe oviposition commenced only from the 14th week. Only 10% of total
adults and 11.3% of total eggs were on the non-target
plant, and none of these eggs hatched. These tests demonstrated that although the beetle can spill-over from
the target weed to the non-target native plant and cause
feeding damage, the non-target plant could not sustain a
viable insect population on its own. However, owing to
the perceived risk to non-target species, this agent was
not approved for field release in Australia (Dhileepan et
al. 2005; Raghu et al. 2007).
Carvalhotingis hollandi (Drake) (Tingidae). This
leaf-feeding tingid was collected on cat’s claw creeper
from Curitiba in Brazil and from Posadas in Argentina in
April 2002 (Williams et al. 2008). A laboratory colony of
the tingid was established in quarantine at ARC-PPRI,
Pretoria. Females lay eggs along the vein on the upper
(axial) side of the leaves and the emerging nymphs feed as
a group, causing chlorosis. Studies in South Africa confirmed that C. hollandi is highly host-specific, hence it
was approved for field release (Williams et al. 2008). The
tingid was imported into Australia in 2004 but, due to
difficulties in establishing a colony under high-security
conditions, it could not be cultured in quarantine and
host-specificity tests were not conducted.
Agents released
Carvalhotingis visenda (Drake & Hambleton) (Tingidae). This tingid (Fig. 4) was collected on cat’s claw
creeper from Curitiba in Brazil and from Posadas in
Argentina in April 2002 (Williams et al. 2008), and
imported from South Africa to Australia in 2004 (Treviño et al. 2006). The tingid developed and reproduced
throughout the year and there was no evidence of winter
diapause. The females lived longer (48.0 ± 7.3 days) than
males (24.4 ± 7.9 days) and laid 82.2 ± 13.2 eggs in their
life-time, with an average of 6.8 ± 0.8 eggs per day after a
pre-oviposition period of 3.4 ± 0.7 days (Dhileepan et al.
2010b). The eggs were laid in groups along the main vein
on the undersides of leaves. The emerging nymphs fed as
a group on the underside of leaves, sucking out the cell
contents of leaves and causing chlorosis. The nymphs
developed through five nymphal instars in 16.9 ± 1.4
days. Temperatures between 20°C and 30°C were the
most favourable for adult survival, oviposition, egg hatching and nymphal development (Dhileepan et al. 2010a).
Figure 4: Carvalhotingis visenda adult and nymphs. Photo: J
McCarthy, Qld Government.
© CSIRO 2012
Published by CSIRO Publishing, http://www.publish.csiro.au/
091102 Biological Control of Weeds in Aust 4pp.indd 355
19/12/11 21:06:59050
356
Biological Control of Weeds in Australia
The tingid fed and reproduced on both long- and
short-pod varieties of M. unguis-cati. Pre-release evaluations confirmed that feeding by the tingid significantly
affected the growth and productivity of cat’s claw creeper
seedlings (Conrad and Dhileepan 2007) by reducing the
chlorophyll contents of damaged leaves by 5–17%, resulting in a 31–49% reduction in photosynthesis (Bayliss
2006). The pre-release evaluations also indicated that
even a single tingid generation could significantly reduce
above-ground shoot and subterranean tuber growth
(Conrad and Dhileepan 2007; Bayliss 2006).
The host-specificity trials in Australia confirmed that
the tingid is host-specific and does not pose risk to any
non-target plants (Dhileepan et al. 2007b). Climatic modelling (Rafter et al. 2008) and thermal tolerance (Dhileepan
et al. 2010a) studies suggest that majority of the cat’s claw
creeper-infested areas in Qld and NSW are climatically
suitable for C. visenda. The potential number of generations it can complete in a year in Australia ranged from
three to eight, with more generations in Qld than in NSW
(Dhileepan et al. 2010a). To increase the virulence of the
existing lab colony, a fresh colony of C. visenda was
imported from Paraguay in 2007 and mixed with the existing colony in Australia; progeny from the mixed colony are
currently being field released. The tingid was approved for
field release in 2007 and since then more than half a million adults and nymphs have been released at 72 sites in
Qld and northern NSW in partnership with local community groups (Dhileepan et al. 2010b). Field establishment of
C. visenda was evident on both varieties of M. unguis-cati
in 80% of the release sites, but the agent appears to spread
slowly in the field (Dhileepan et al. 2010b). The spread was
mostly horizontal along the ground-level infestations, less
often vertically on the plants climbing on trees. Field establishment of C. visenda has also been reported from South
Africa (King and Dhileepan 2009).
Hypocosmia pyrochroma Jones (Lepidoptera: Pyralidae). A laboratory colony of this leaf-tying moth was first
established in Pretoria, South Africa, from material collected on cat’s claw creeper from sites near Curitiba in
Brazil and Posadas in Argentina in April 2002 (Williams
2003a). The moth (Fig. 5) was imported to Australia in
2005 after tests in South Africa proved it to be highly hostspecific. Host-specificity tests in Australia involving 38
plant species in 10 families confirmed that H. pyrochroma
is a highly specific biological control agent that does not
pose risk to non-target plants (Dhileepan et al. 2007a).
The moth lays eggs singly on the undersides of leaves
and in the crevices of woody stems. Eggs hatch in two
Figure 5: Hypocosmia pyrochroma adult. Photo: J McCarthy, Qld
Government.
weeks. The larvae feed destructively by tying leaves
together by silk webs, which create silken tunnels. Larvae
go though six instars in four weeks. Fully grown larvae
pupate in the soil, 2–3 cm below the soil surface, and the
majority of the adults emerge after four weeks. Pupae
undergo diapause from late autumn (April–May) to early
spring (September–October). Larvae reared under a
higher temperature (25–30°C) and longer light regime
(14 h) in the laboratory did not undergo pupal diapause.
Females lived for around 10 days and laid up to 120 eggs
after a two-day pre-oviposition period (Williams 2003a).
The female moth laid eggs and the emerging larvae
developed equally well on both long- and short-pod varieties of cat’s claw creeper. Feeding and leaf-tying by
H. pyrochroma larvae severely damage foliage (Williams
2003b) and result in reduced plant growth and tuber production (Snow et al. 2006). Under quarantine conditions,
H. pyrochroma larval feeding resulted in death of cat’s
claw creeper seedlings as leaves were fed upon and turned
into silken tunnels. It is anticipated that the moth will
establish along the coastal regions of south-eastern Qld
and northern NSW, and has the potential to complete at
least three generations in a year (October to April).
The leaf-tying moth was approved for field release in
2008 and since then field releases of larvae and adults
have been made across 17 sites in south-eastern Qld and
northern NSW. An improved laboratory rearing method,
replacing potted plants with corrugated paper for oviposition, cut foliage for larval feeding and sterilised sand for
pupation in temperature-controlled rearing cages, has
resulted in the field release of large numbers of larvae and
adults. Though larvae have been recovered from some of
© CSIRO 2012
Published by CSIRO Publishing, http://www.publish.csiro.au/
091102 Biological Control of Weeds in Aust 4pp.indd 356
19/12/11 21:06:59644
357
Macfadyena unguis-cati (L.) A.H.Gentry – cat’s claw creeper
however, presents a significant challenge to the rearing and
specificity testing of the weevil in quarantine.
DISCUSSION
Figure 6: Leaf-mining by Hylaeogena jureceki larvae. a) With
pupal cells (P). b) The larva. Photo: D Taylor, Qld Government.
the release sites, it is too early to determine its field establishment status in Australia.
Other promising agents
Hylaeogena jureceki (Obenberger) (Coleoptera: Buprestidae). This leaf-mining jewel beetle native to Argentina,
Brazil, Paraguay and Trinidad was collected from Argentina and Brazil in April 2002 (Williams 2003b). The adults
are small and blackish in colour with a slight metallic
sheen and live for more than five months. Both adults and
larvae cause damage; adults feed on leaves, while the larvae
mine the leaves (Fig. 6). Females lay one to two eggs per day
singly on the leaves, and the eggs hatch in 10–12 days. The
emerging larvae go though three larval instars in 10–13
days. Mature larvae pupate on the leaf (Fig. 6) and adults
emerge after 12–16 days. Host-specificity tests in South
Africa indicated that the jewel beetle is specific to cat’s claw
creeper and hence it was approved for field release there
(King et al. 2011). The jewel beetle was imported to Australia in 2009 and host-specificity tests have been completed and the agent is awaiting approval for field release.
Apteromechus notatus (Hustache) (Coleoptera: Curculionidae). In its native range, A. notatus has been
observed in large numbers destroying up to 80% of the
seeds found within developing pods, thereby reducing seed
rain (King and Dhileepan 2009). Adults are long-lived and
are thought to lay eggs on green or immature pods. Thereafter, hatching larvae burrow into the pod and feed on
numerous seeds before pupating. After overwintering as
either pupae or newly emerged adults within the pod, the
next generation of adults emerges in spring to coincide
with flowering and early pod production. This life-history,
Simulated herbivory studies indicated that cat’s claw
creeper is susceptible to leaf herbivory. Hence, leaf-feeding agents have been prioritised and imported for hostspecificity tests. However, for the leaf herbivory to be
effective, multiple defoliation events would be required to
slow the climbing habit of the liana and reduce its tuber
resources (St Pierre 2007). As a result, five agents, all leaffeeding, have been imported for host-specificity testing.
Among them, only two agents have been field released so
far, while the third agent is undergoing host-specificity
tests in quarantine.
There is no evidence of any competition between the
two leaf-feeding insects being field released, C. visenda
and H. pyrochroma, as both agents show distinct preference for different niches within the plant in laboratory
studies. The tingid prefers to feed and oviposit on mature
and older leaves (Bayliss 2006; Conrad and Dhileepan
2007), while the leaf-tying moth preferentially oviposits
on shoot tips and young leaves (Snow et al. 2006). This is
further confirmed by field observations, where the tingid
(C. visenda) infestation was more evident on mature and
older leaves at ground level. In contrast, larvae of the leaftying moth (H. pyrochroma) were often recovered from
foliage on the tree stems.
Climate-matching and plant genotypic studies
directed surveys to areas around the southern parts of the
native distribution of cat’s claw creeper, in particular
Paraguay, the southern reaches of Brazil and north-eastern Argentina. Biological control agents sourced from
these regions with similar climatic conditions and matching plant genotypes are more likely to be successful. A
freshly field-collected culture of the leaf-tying moth and
the tingid from Paraguay was mixed with the existing lab
colony that originated from field-collected materials in
2002 to enhance the virulence and genetic diversity of the
lab colonies of both agents.
The recruitment of cat’s claw creeper in the field is
primarily from seeds, not from vegetative propagation as
previously thought (Osunkoya et al. 2009). Though the
specialist leaf-herbivores, through reduction of photosynthetic leaf surfaces and hence assimilates, should be effective in reducing the existing tuber bank (Conrad and
Dhileepan 2007; Bayliss 2006; St Pierre 2007), they may
have only limited impact on the spread or establishment
© CSIRO 2012
Published by CSIRO Publishing, http://www.publish.csiro.au/
091102 Biological Control of Weeds in Aust 4pp.indd 357
19/12/11 21:06:59880
358
Biological Control of Weeds in Australia
of new tubers or populations from new seed inputs.
Hence, future biological control efforts should focus
equally on reducing seed production and spread, by targeting fruit pods or mature seeds using a specialist podand seed-feeding weevil (e.g. A. notatus) from Brazil.
ACKNOWLEDGEMENTS
We thank Dr Stefan Neser, Hester Williams and Anthony
King of ARC-PPRI, South Africa, for supplying the biological control agents; Mariano Treviño, Jayd McCarthy,
Mathew Shortus, Deanna Bayliss and Di Taylor for technical support; and Bill Palmer and Dane Panetta for comments on the manuscript.
REFERENCES
Bayliss D (2006) The pre-release evaluation of a potential
biological control agent (Carvalhotingis visenda) for
cat’s claw creeper (Macfadyena unguis-cati) – plant
growth and physiological response to herbivory. BSc
Hons thesis. School of Integrative Biology, University
of Queensland, Australia.
Conrad KA and Dhileepan K (2007) Pre-release evaluation of the efficacy of the leaf-sucking bug Carvalhotingis visenda (Heteroptera: Tingidae) as a biological
control agent for cat’s claw creeper Macfadyena
unguis-cati (Bignoniaceae). Biocontrol Science and
Technology 17, 303–311.
Dhileepan K, Treviño M, Donnelly GP and Raghu S
(2005) Risk to non-target plants from Charidotis auroguttata (Chrysomelidae: Coleoptera), a potential biocontrol agent for cat’s claw creeper Macfadyena
unguis-cati (Bignoniaceae) in Australia. Biological
Control 32, 450–460.
Dhileepan K, Snow EL, Rafter MA, McCarthy J, Treviño
M and Wilmot Senaratne KAD (2007a) Leaf-tying
moth Hypocosmia pyrochroma (Lepidoptera: Pyralidae), a host specific biological control agent for cat’s
claw creeper Macfadyena unguis-cati (Bignoniaceae)
in Australia. Journal of Applied Entomology 131,
564–568.
Dhileepan K, Treviño M and Snow EL (2007b) Specificity
of Carvalhotingis visenda (Hemiptera: Tingidae) as a
biocontrol agent for cat’s claw creeper Macfadyena
unguis-cati (Bignoniaceae) in Australia. Biological
Control 41, 282–290.
Dhileepan K, Bayliss D and Treviño M (2010a) Thermal
tolerance and potential distribution of Carvalhotingis
visenda (Hemiptera: Tingidae), a biological control
agent for cat’s claw creeper Macfadyena unguis-cati
(Bignoniaceae). Bulletin of Entomological Research
100, 159–166.
Dhileepan K, Treviño M, Bayliss D, Saunders M, McCarthy J, Shortus M, Snow EL and Walter GH (2010b)
Introduction and establishment of Carvalhotingis
visenda (Hemiptera: Tingidae) as a biological control
agent for cat’s claw creeper Macfadyena unguis-cati
(Bignoniaceae) in Australia. Biological Control 55,
58–62.
Downey PA and Turnbull I (2007) The biology of Australian weeds. 48. Macfadyena unguis-cati (L.) A.H.
Gentry. Plant Protection Quarterly 22, 82–91.
Hernandez JR and Hennen JF (2003) Rust fungi causing
galls, witches’ brooms, and other abnormal plant
growths in northwestern Argentina. Mycologia 95,
728–755.
King AM and Dhileepan K (2009) Clinging on: a review
on the biological control of cat’s claw creeper. Biocontrol News and Information 30, 53N–56N.
King AM, Williams HE and Madire LG (2011) Biological
control of cat’s claw creeper. Macfadyena unguis-cati
(L.) A.H.Gentry (Bignoniaceae), in South Africa. African Entomology 19, 366–377.
Osunkoya OO, Pyle K, Scharaschkin T and Dhileepan K
(2009) What lies beneath? The pattern and abundance
of the subterranean tuber bank of the invasive liana
cat’s claw creeper, Macfadyena unguis-cati (Bignoniaceae). Australian Journal of Botany 57, 132–138.
Prentis PJ, Sigg DP, Raghu S, Dhileepan K and Lowe AJ
(2009) Worldwide phylogeography of two globally
invasive plants reveals contrasting introduction histories and genetic dynamics. Diversity and Distributions
15, 822–830.
Rafter MA, Wilson AJ, Wilmot Senaratne KAD and Dhileepan K (2008) Modelling climatic similarities in
native and introduced ranges of cat’s claw creeper
Macfadyena unguis-cati (Bignoniaceae) to prioritise
areas for exploration and release of biological control
agents. Biological Control 44, 169–179.
Raghu S and Dhileepan K (2005) The value of simulating
herbivory in selecting effective weed biological control
agents. Biological Control 34, 265–273.
Raghu S, Dhileepan K and Treviño M (2006) Response of
an invasive liana to simulated herbivory: implications
for its biological control. Acta Oecologica 29, 335–345.
Raghu S, Dhileepan K and Scanlan J (2007) Predicting
the risk to non-target species in classical biological
© CSIRO 2012
Published by CSIRO Publishing, http://www.publish.csiro.au/
091102 Biological Control of Weeds in Aust 4pp.indd 358
19/12/11 21:07:00024
359
Macfadyena unguis-cati (L.) A.H.Gentry – cat’s claw creeper
control: a systems modeling approach. Ecological
Modelling 208, 247–262.
Shortus M and Dhileepan K (2011) Two varieties of the
invasive liana, cat’s claw creeper, Macfadyena unguiscati (Bignoniaceae) in Queensland, Australia. Proceedings of the Royal Society of Queensland 116, 13–20.
Sigg DP, Lowe A, Raghu S and Dhileepan K (2006) ‘Using
genetic tools to assess the provenance of an invasive
liana, Macfadyena unguis-cati, in Australia’. Report to
the Qld Dept of Natural Resources, Mines and Water,
July 2006.
Snow EL, McCarthy J, Treviño M, Senaratne KADW and
Dhileepan K (2006) Biological control of cat’s claw
creeper (Macfadyena unguis-cati): the potential of the
leaf-tying pyralid moth Hypocosmia pyrochroma
Jones. In Proceedings of the 15th Australian Weeds
Conference, 24–28 September, Adelaide. (Eds C Preston, JH Watts and ND Crossman) pp. 599–600. Weed
Management Society of South Australia, Adelaide.
Sparks HE (1999) The initiation of a biological control
programme against Macfadyena unguis-cati (L.)
Gentry (Bignoniaceae) in South Africa. African Entomology Memoir No. 1, 153–157.
St Pierre S (2007) The response of an invasive liana to
defoliation in sun and shade and the effects of plant
light history on behaviour of a potential biocontrol
species. BSc Hons thesis. School of Integrative Biology,
University of Queensland, Australia.
Treviño M, Snow EL, Senaratne KADW, Conrad C and
Dhileepan K (2006) Leaf-sucking tingid (Carvalhotingis visenda): a potential biological control agent for
cat’s claw creeper (Macfadyena unguis-cati). In Proceedings of the 15th Australian Weeds Conference.
24–28 September, Adelaide. (Eds C Preston, JH Watts
and ND Crossman) pp. 605–606. Weed Management
Society of South Australia, Adelaide.
Vivian-Smith G and Panetta FD (2004) Seedbank ecology
of the invasive vine, cat’s claw creeper (Macfadyena
unguis-cati (L.) Gentry). In Proceedings of the 14th
Australian Weeds Conference. 6–9 September, Wagga
Wagga, NSW. (Ed SB Johnson) pp. 531–537. Weed
Society of New South Wales, Wagga Wagga.
Williams HE (2002) Life history and laboratory host range
of Charidotis auroguttata (Boheman) (Coleoptera:
Chrysomelidae), the first natural enemy released against
Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) in
South Africa. Coleopterists Bulletin 56, 299–307.
Williams HE (2003a) ‘Host specificity report to the
National Department of Agriculture: Directorate of
Plant Health and Quality in relation to an application
for permission to undertake the release of the cat’s
claw creeper leaf-tying moth, Hypocosmia pyrochroma,
a potential biocontrol agent for Macfadyena unguiscati in South Africa’. Agricultural Research Council,
Plant Protection Research Institute, Pretoria, South
Africa.
Williams HE (2003b) ‘Host specificity report to the
National Department of Agriculture: Directorate of
Plant Health and Quality in relation to an application
for permission to undertake the release of Hylaeogena
(Hedwigiella) jureceki Obenberger, a biological control
agent for Macfadyena unguis-cati L. Gentry (Bignoniaceae) in South Africa’. Agricultural Research Council, Plant Protection Research Institute, Pretoria, South
Africa.
Williams HE, Neser S and Madire S (2008) Candidates
for biocontrol of Macfadyena unguis-cati in South
Africa: biology, host ranges and potential impact of
Carvalhotingis visenda and Carvalhotingis hollandi
under quarantine. BioControl 53, 945–956.
© CSIRO 2012
Published by CSIRO Publishing, http://www.publish.csiro.au/
091102 Biological Control of Weeds in Aust 4pp.indd 359
19/12/11 21:07:00144