Host range of Cybocephalus flavocapitis and Cybocephalus ...

Journal of Asia-Pacific Entomology 15 (2012) 595–599
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Journal of Asia-Pacific Entomology
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Host range of Cybocephalus flavocapitis and Cybocephalus nipponicus, two potential
biological control agents for the cycad aulacaspis scale, Aulacaspis yasumatsui
Sing-Ying Song, Ching-Wen Tan, Shaw-Yhi Hwang ⁎
Department of Entomology, National Chung Hsing University, Taichung, Taiwan
article
info
abstract
Article history:
Received 13 March 2012
Revised 2 June 2012
Accepted 4 June 2012
Available online 11 June 2012
Keywords:
Aulacaspis yasumatsui
Cybocephalus flavocapitis
Cybocephalus nipponicus
Host scale range
Host-range and host-specificity tests were performed with Cybocephalus flavocapitis T. R. Smith (Coleoptera:
Cybocephalidae) and Cybocephalus nipponicus Endrödy-Younga (Coleoptera: Cybocephalidae), two biological control
candidates against the invasive cycad aulacaspis scale, Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae).
Seventeen native scale species plus the invasive A. yasumatsui scale were tested in growth chambers using nochoice
tests and hosts suitable for each of the two predatory beetles. The results revealed that the two Cybocephalus
beetles, one imported species from Thailand and one native species, both fed on relatively similar scale prey species.
Additionally, the adult beetles of these two species oviposited only on Diaspididae scales. The results showed
that both Cybocephalus beetles may share a similar host niche in Taiwan.
© Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society,
2012. Published by Elsevier B.V. All rights reserved.
Introduction
The cycad aulacaspis scale (CAS), Aulacaspis yasumatsui Takagi
(Hemiptera: Diaspididae), is an armored scale that originated in Thailand
(Takagi, 1977). As a result of human activity and worldwide trading of
cycads, this cycad scale has spread rapidly to many countries including
China, Singapore, Hong Kong, Taiwan, Cayman Islands, Puerto Rico,
Vieques Island, U.S. Virgin Islands, the Hawaiian islands, and Guam
(The International Union for Conservation of Nature and Natural Resources/Species
Survival Commission-IUCN/SSC, 2005; Germain and
Hodges, 2007). The CAS has recently become a major threat to many cultivated
and native cycads, because it is multivoltine. The CAS has a relatively
high reproductive potential and feeds on above and below ground
cycad tissues (Howard et al., 1999; Bailey et al., 2010; Marler and Moore,
2010).
The CAS was first identified in Taoyuan county, Taiwan in 2000 (Chao
and Lai, 2005) and has quickly spread to most of the island. Since then, the
CAS has threatened cultivated cycads, such as Cycas revoluta Thunberg
(Cycadales: Cycadaceae), in home gardens, commercial nurseries, and
local landscapes in Taiwan. In addition, Cycas taitungensis, anendemic
cycad species of Taiwan have also encountered the threat from this invasive
pest (IUCN/SSC, 2005). Cy. taitungensis occurs mainly in forest
reserves in the mountain area of Hongye, Taitung county, and its association
with the CAS in these forest reserves has been monitored since 2004
(Chao and Lai, 2005). The results of these monitoring projects have
⁎ Corresponding author at: Department of Entomology, National Chung Hsing University,
250 Kuo Kuang Road, Taichung, Taiwan 402, ROC. Tel.: +886 4 22840363; fax: +886 4
22875024.
E-mail address: oleander@dragon.nchu.edu.tw (S-Y. Hwang).
indicated that CAS infestations do occur, but that they are moderate in
most Cy. taitungensis trees (Hwang, unpublished data). However, the
CAS has destroyed and significantly affected the fitness of many Cy.
taitungensis seedlings in these forest reserves.
However, a promising control protocol for eradicating the CAS in
cultivated or wild cycads is lacking. The IUCN has recommended several
CAS control measures, such as insecticides, biological control, mechanical/cultural
methods, as well as integrating these measures (IUCN/SSC,
2005). Several insecticides have been tested on the CAS during cycad
cultivation (Emshousen et al., 2004). However, the CAS are sheltered
by a protective wax covering and tuck themselves into crevices of the
host plant, making the aerosol insecticide application less effective
(Marler and Moore, 2010). Systemic insecticides could be applied directly
to the soil or leaves to control the CAS in small scale areas, such
as cultivated gardens. However, the wild cycad Cy. taitungensis is
scattered over a wide area and is distributed over remote mountain forest
reserves in difficult terrain. As a result, applying pesticides in these
forest reserves is very difficult and could have a serious adverse impact
on other nontarget organisms.
The IUCN has also proposed introduction of natural enemies as the
most cost and labor-effective control method for CAS infestation (IUCN/
SSC, 2005). Since 1998, the parasitic wasp, Coccobius fulvus (Compere
and Annecke) (Hymenoptera: Aphelinidae), and the predatory beetle,
Cybocephalus nipponicus Endrödy-Younga (Coleoptera: Cybocephalidae),
have been imported from Thailand and released in Florida for classic biological
control (Hodges et al., 2003). Cybocephalids feed on various hosts
but generally their host sources are scale insects (Smith and Cave, 2006,
2007). In North America, C. nipponicus feeds mainly on the CAS, Fiorinia
externa Ferris (Hemiptera: Diaspididae), and Unaspis euonymi (Comstock)
(Hemiptera: Diaspididae) (Drea and Carlson, 1988; Alvarez and
1226-8615/$ – see front matter © Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society, 2012. Published by Elsevier B.V. All rights
reserved.

596 S-Y. Song et al. / Journal of Asia-Pacific Entomology 15 (2012) 595–599
van Driesche, 1998a,b). Studies have indicated that the relationship between
C. nipponicus and scale is density dependent (Smith and Cave,
2006). Therefore, the reproductive biology of C. nipponicus makes it a
good biological control candidate for the CAS. In 2003, C. nipponicus was
imported from Thailand to Taiwan to evaluate its biological control potential
for the CAS (Bailey et al., 2010). The results indicated that
C. nipponicus prey on the CAS and also show a functional response on
the CAS (Bailey et al., 2010).
In addition to C. nipponicus, a local cybocephalid beetle, Cybocephalus
flavocapitis T. R. Smith (Coleoptera: Cybocephalidae) has been discovered
on cycad trees (Smith and Bailey, 2007). C. flavocapitis is very morphologically
similar to C. nipponicus, but male morphology easily
distinguishes the two beetles. The male of C. flavocapitis has a yellow
head and a black pronotum, whereas the C. nipponicus male has both a
yellow to brown head and pronotum (Smith and Bailey, 2007). A comprehensive
evaluation of the biological control potential of these two
cybocephalid beetles on the CAS has been conducted, and the results revealed
that these two beetles have a very similar predation rate (Bailey
et al., 2011). However, knowledge regarding their host range in Taiwan
is very limited. Results of field surveys have revealed that these two
cybocephalid beetles occur over most of the island and have overlapping
ranges (Hwang, unpublished data). Understanding the host range of
any biological control agent is one of the fundamental steps when evaluating
its control potential. As C. flavocapitis is a native species, it is
expected to have a broader host scale range, making it less suitable for
biological control purposes. In addition, competition may occur between
these two species if their host ranges are similar; thus, reducing
their predation efficacy. To comprehensively manage the CAS in Taiwan,
it is crucially important to understand the host range of both C. nipponicus
and C. flavocapitis. Therefore, the objective of this study was to evaluate
the host scale range and the host suitability of both these predatory
beetles.
Materials and methods
Insects
Seventeen native scale species in six families and the A. yasumatsui
scale (CAS) were tested as prey species for the predatory beetle
(Table 1). They were collected from ornamental trees in Pingtung
county, Taiwan, and were identified at the Applied Zoology
Table 1
List of scale species used in this study.
Test Scale Species
Family Margarodidae
Icerya aegyptiaca (Douglas)
Family Pseudococcidae
Ferrisia virgata (Cockerell)
Maconellicoccus hirsutus (Green)
Planococcus citri (Risso)
Pseudococcus longispinus (Targ.)
Family Asterolecaniidae
Bambusaspis pseudomiliaris (Green)
Family Coccidae
Coccus viridis (Green)
Saissetia coffeae (Walker)
Family Diaspididae
Aspidiotus destructor (Signoret)
Aulacaspis murrayae (Takahashi)
Aulacaspis tubercularis (Newstead)
Aulacaspis yabunikkei (Kuwana)
Aulacaspis yasumatsui (Takagi)
Chrysomphalus aonidum (Linnaeus)
Fiorinia taiwana (Takahashi)
Parlatoria crotonis (Douglas)
Kuwanaspis neolinearis (Takahashi)
Family Kerridae
Laccifer lacca (Kerr)
Host Plant
Psidium guajava
Euphorbia pulcherrima
Hibiscus rosa-sinensis
Acacia confusa
Dracaena godseffiana
Bambusa stenostachya
Manilkara zapota
Pseuderanthemum atropurpureum
Annona squamosa
Murraya paniculata
Mangifera indica
Cinnamomum camphora
Cycas revoluta
Citrus maxima
Chrysalidocarpus lutescens
Mangifera indica
Dendrocalamus latiflorus
Litchi chinensis
Department (Agricultural Research Institute, Taiwan). The scales
were reared on their respective preferred host plants based on our
field observations and suggestions from the literature (Wong et al.,
1999). Each scale species was distributed over four potted host plants
placed in BugDorm insect rearing cages (60×60×60 cm 3 ; MegaView
Science Co., Ltd., Taichung, Taiwan) and maintained under greenhouse
conditions. Potted plants were watered daily, and the cages
were monitored daily for the scale development. Once the host plants
were fully infested with the scales, fully infested twigs were used for
the beetle host and oviposition range test.
The predatory beetle C. nipponicus was cultivated from the original
imported stock from Bangkok, Thailand (Bailey et al., 2011). Cycad
plants (Cy. revoluta) infested with the CAS were used to feed the beetles.
Each of the four cycad seedlings (~30 cm in height), in mixed
stages of being infested with the CAS, were placed with the aforementioned.
Ten pairs of male and female beetles were then placed in each
cage and kept under greenhouse conditions. The plants were watered
every 3 days, and emerging new adult beetles were used for bioassays.
The other predatory beetle, C. flavocapitis, was collected from
local cycad trees in Cishan, Kaohsiung county, Taiwan. They were
treated the same way as C. nipponicus. After the cycad seedlings
were partially covered with the CAS, 10 pairs of C. flavocapitis collected
from the field were placed in the cages. The newly emerged naive
adults (~1 month) were then used for the bioassays.
Host acceptance test
Adult feeding test
Prey acceptance by the adult C. nipponicus and C. flavocapitis was
examined in a no-choice experiment using 18 scale species
(Table 1). Twenty pairs of adult C. nipponicus or C. flavocapitis, starved
for 24 hr, were placed in 90×15 (D×H) mm Petri dishes containing
one of the 18 prey attached to sections (b5 cm) of host plant branches
in the growth chamber (12 L 12D hr photoperiod) at a constant 30±
1 °C. Each Petri dish was checked five times at 30 min intervals to observe
beetle feeding behavior. The beetles were recorded as accepting
when they showed feeding and ingestion of the prey species.
Oviposition test
A no-choice test was conducted to assess the effect of prey species
on oviposition acceptance by female C. nipponicus and C. flavocapitis.
All tests were conducted in Petri dishes in the growth chamber
(12 L 12D hr photoperiod) at 30±1 °C. Similar to the adult feeding
test, the same 18 scale species were used in this bioassay. Twenty
pairs of adult C. nipponicus or C. flavocapitis (fed with A. yasumatsui
eggs during immature stages) were placed in a Petri dish with one
bunch of host plant twigs infested with the test prey. A host plant
bunch was made up of small branches (5–7 cm length) of preyinfested
host plant held together by wrapping the cut end with
moist cotton balls to prevent the twigs from desiccating. The duration
of each test was 1 day. Both the C. nipponicus and C. flavocapitis were
observed to determine if any ovipositon behavior occurred 24 hr after
the test.
Host suitability test
Based on the results of the oviposition test, female C. nipponicus and
C. flavocapitis deposited eggs on six of the eight tested Diaspididae scale
species. Therefore, only these six Diaspididae scale species were used in
the host suitability bioassay. The six scale species, Aulacaspis yabunikkei
(Kuwana), A. murrayae (Takahashi), A. destructor (Signoret), Aulacaspis
tubercularis (Newstead), A. yasumatsui, andChrysomphalus aonidum
(Linnaeus) were all used in the host suitability bioassay for C. flavocapitis.
However, some scale materials were short of supply when this bioassay
was conducted with the C. nipponicus beetle. Therefore, only three host
scales were included in the C. nipponicus bioassay. The scale species

S-Y. Song et al. / Journal of Asia-Pacific Entomology 15 (2012) 595–599
597
were A. yabunikkei (Kuwana), A. murrayae (Takahashi), and A. destructor
(Signoret). The scale species were reared on their respective preferred
host plants. Potted plants were watered daily, and the cages were monitored
on a daily basis for scale development. When the host plants were
fully infested with scale, the scale-infested twigs were used for the predatory
beetle host suitability test. All tests were conducted in 55 mm diamter×15
mm high Petri dishes in a growth chamber (12 L 12D h
photoperiod) at a constant 30±1 °C. The eggs of C. nipponicus and C.
flavocapitis were collected from adult females and individually placed in
the Petri dish with a bunch of host plant twigs infested with test prey.
The emerging instars began feeding on the host scales. Small branches
(5–7 cm length) infested with prey were wrapped on their cut end
with moist cotton balls to prevent the twigs from desiccating. The host
plant twigs infested with scale were replaced weekly. The duration of
the life stage of each beetle was recorded. Ten to twenty replicates
were conducted for each trial.
Statistical analysis
Means and standard errors of the life stage durations in the host
suitability bioassay were calculated for each trial. Data were analyzed
using SAS for Windows V9.2 (SAS Institute, Cary, NC, USA). The effects
of the host scale species on the duration of beetle growth were analyzed
with an analysis of variance (Proc GLM), followed by mean
comparisons using Tukey's multiple range test. A Pb0.05 was considered
significant.
Results
Adult feeding and oviposition experiments
The results of the adult feeding test showed that both adult
C. nipponicus and C. flavocapitis fed on Bambusaspis pseudomiliaris
Green (Asterolecaniidae) and on all Diaspididae species (Table 2).
In addition, the imported C. nipponicus fed on brown coffee scale,
Saissetia coffeae Walker (Coccidae) and striped mealy bug, Ferrisia
virgata Cockerell (Pseudococcidae). However, neither beetle species
fed on any of the Margarodidae or Kerridae scale prey.
The results of the no-choice oviposition test revealed oviposition behavior
of female C. nipponicus and C. flavocapitis on six Diaspididae scale
species (Table 2). The prey species included coconut scale (A. destructor
Signoret), A. murrayae Takahashi, A. tubercularis Newstead, cinnamomum
scale (A. yabunikkei Kuwana), cycad aulacaspis scale (A. yasumatsui
Takagi), and artocarpus scale (Chrysomphalus aonidum L.).
Host suitability experiment
The results of the host suitability test indicated that the egg and larval
stages of C. nipponicus grew relatively similarly on the three tested
scale species (Table 3). The durations of the pupal stage, adult stage,
and longevity of C. nipponicus were significantly different among the
three prey species (Table 3). The life span of C. nipponicus was much
longer when fed on Aspidiotus destructor (Signoret) (111.30 days)
than when they fed on A. yabunikkei (Kuwana) (33.70 days). The results
of the C. flavocapitis study also showed that the durations of the egg and
early larval stages were similar among the six prey species (Table 4).
The duration of the third instars varied significantly among the six
prey scale species, ranging from 2.7 to 3.83 days (Table 4). The pupal
stages also differed significantly among the test scale species. However,
the adult stages of C. flavocapitis varied greatly among the tested scale
species (Table 4). The life span of C. flavocapitis was longest when
they fed on A. yasumatsui (133.5 days) and shortest when they fed on
A. murrayae (69.2 days). The C. flavocapitis that fed on C. aonidum all
died when they emerged from the pupa stage; thus, no adult and no
life span data were recorded (Table 4). In summary, C. nipponicus survived
for>100 days on Aspidiotus destructor only; however, C. flavocapitis
Table 2
Results of the feeding and oviposition test of the scale prey screened as the host of adult C.
flavocaputus and C. nipponicus (+, positive feeding or oviposition response; −, negative
feeding or oviposition response).
Test Scale Species C. flavocapitis C. nipponicus
survived well on three scale species such as A. yabunikkei, A. tubercularis,
and A. yasumatsui (Tables 3 and 4).
Discussion
Adult
feeding
Oviposition
Adult
feeding
Family Margarodidae
Icerya aegyptiaca (Douglas) − − − −
Family Pseudococcidae
Ferrisia virgata (Cockerell) − − + −
Maconellicoccus hirsutus − − − −
(Green)
Planococcus citri (Risso) − − − −
Pseudococcus longispinus
(Targ.)
− − − −
Family Asterolecaniidae
Bambusaspis pseudomiliaris
(Green)
+ − + −
Family Coccidae
Coccus viridis (Green) − − − −
Saissetia coffeae (Walker) − − + −
Family Diaspididae
Aspidiotus destructor
+ + + +
(Signoret)
Aulacaspis murrayae
+ + + +
(Takahashi)
Aulacaspis tubercularis + + + +
(Newstead)
Aulacaspis yabunikkei
+ + + +
(Kuwana)
Aulacaspis yasumatsui + + + +
(Takagi)
Chrysomphalus aonidum + + + +
(Linnaeus)
Fiorinia taiwana (Takahashi) + − + −
Parlatoria crotonis (Douglas) + − + −
Kuwanaspis neolinearis
(Takahashi)
+ − + −
Family Kerridae
Laccifer lacca (Kerr) − − − −
Oviposition
Both types of Cybocephalus beetles feed on similar scale prey species.
The adult beetles of both species oviposit only on Diaspididae
scale species. Our results indicated that the CAS, A. yasumatsui, is possibly
one of the most suitable host preys for both beetle species. Our
results also revealed that both Cybocephalus beetles have a similar
host range in Taiwan and that this niche overlapping phenomenon
may affect their predatory efficiency.
Cybocephlids feed mainly on armored scale (Diaspididae) (Alvarez
and van Driesche, 1998a). They also feed on whiteflies (Aleyrodidae),
mealy bug (Pseudococcidae), and citrus red mite, Panonychus citri
(McGgregor) (Tanaka and Inoue, 1980; Endrödy-Younga, 1982). The
imported C. nipponicus has been reported to feed on many armored (Diaspididae)
scale insects (Smith and Cave, 2006; Mayer et al., 2008). This
finding was confirmed by our results, showing that C. nipponicus were
able to feed on all the tested Diaspididae scale species. Additionally,
C. nipponicus showed a wider host range than that reported previously
(Smith and Cave, 2006), as it had the ability to feed on scales from
other families, including F. virgata (Pseudococcidae), B. pseudomiliaris
(Asterolecaniidae), and S. coffeae (Coccidae). In contrast to C. nipponicus,
C. flavocapitis has been reported to feed only on A. yasumatsui (Smith

598 S-Y. Song et al. / Journal of Asia-Pacific Entomology 15 (2012) 595–599
Table 3
Developmental duration (in days; mean ±SE) of the three prey scale species fed to C. nipponicus (30 ±1 °C).
Scale species Egg 1st instar 2nd instar 3rd instar Pupal Adult Life span
Aspidiotus destructor (Signoret) 4.30 ±0.48 3.20 ±0.42 2.70±0.48 3.10±0.74 9.80 ±1.99 b 88.20±21.98 a 111.30 ±23.07 a
Aulacaspis murrayae (Takahashi) 4.40 ±0.52 2.80 ±0.42 2.50±0.53 2.50±0.71 10.60±1.07 b 10.90±8.96 c 33.70±9.78 c
Aulacaspis yabunikkei (Kuwana) 4.30 ±0.48 2.80 ±0.79 2.80±0.42 2.70±0.67 11.90±0.88 a 63.10±31.38 b 87.60±32.03 b
Means followed by different superscript letters in the same column are significantly different at the 0.05 level by Tukey's HSD test.
Table 4
Developmental duration (in days; mean ±SE) of the six prey scale species fed to C. flavocapitis (30 ±1 °C).
Scale species Egg 1st instar 2nd instar 3rd instar Pupal Adult Life span
Aspidiotus destructor (Signoret) 4.67±0.82 3.67 ±1.21 3.17 ±0.41 3.83 ±0.41 a 11.17±0.75 c 72.50±13.44 b 99.01±18.71 b
Aulacaspis murrayae (Takahashi) 4.60±0.70 3.20 ±0.42 3.00 ±0.00 2.70 ±0.48 b 11.60±1.43 bc 44.10±8.48 c 69.20±8.28 c
Aulacaspis tubercularis (Newstead) 4.40±0.52 3.30 ±0.95 3.30 ±0.95 2.90 ±0.32 b 11.00±1.15 c 101.30 ±12.83 a 126.20±13.71 a
Aulacaspis yabunikkei (Kuwana) 4.50±0.53 3.30 ±0.48 2.90 ±0.32 3.20 ±0.79 ab 10.70±1.06 c 104.70 ±14.47 a 129.30±14.70 a
Aulacaspis yasumatsui (Takagi) 4.70±0.48 3.50 ±0.97 3.30 ±0.95 3.00 ±0.47 b 12.20±0.92 ab 106.80 ±30.96 a 133.50±30.84 a
Chrysomphalus aonidum (Linnaeus) 4.44±0.73 3.67 ±1.00 3.11 ±0.93 3.30 ±1.49 ab 12.75±0.96 a × ×
a Means followed by different superscript letters in the same column are significantly different at the 0.05 level by Tukey's HSD test.
b ×All adults that fed on this scale died after pupation.
and Bailey, 2007). Our study is the first comprehensive host range evaluation
performed on C. flavocapitis, and our results indicate that
C. flavocapitis also feeds on armored (Diaspididae) scale insects such as
B. pseudomiliaris (Asterolecaniidae). To our surprise, we found that
C. nipponicus seemed to have a wider host range than that of C. flavocapitis
in the laboratory test. This was interesting as C. nipponicus was only imported
from Thailand during the past 5 years. It was clear that they had
adapted to the local scale species. Although our no-choice study cannot
reveal the true host range of the C. nipponicus beetle, the results provide
sufficient data for classifying those unattacked test species as nonhosts
(van Driesche and Murray, 2004).
The oviposition test demonstrated that both C. nipponicus and
C. flavocapitis oviposited only on Diaspididae scales. Past studies have
shown that C. nipponicus attacks Diaspididae scales only (Smith and
Cave, 2006; Mayer et al., 2008), but oviposition testing with C. flavocapitis
has never been reported. Although the oviposition test was conducted in
small dishes and may not fully express the host finding behavior of the
predators, it can certainly help to unravel the host acceptance feature of
the predatory beetles (van Driesche and Murray, 2004). This type of nochoice
oviposition test has some value, because it may detect lower
ranked hosts that can be missed during choice tests (van Driesche and
Murray, 2004). The results of our study showed a very narrow host
range for both C. nipponicus and C. flavocapitis. They displayed oviposition
behavior on all tested Aulacaspis scale species and only one Aspidiotus
and one Chrysomphalus species. This finding is consistent with
previous studies showing that the food-plant range in the larval stage
is often broader than the host range accepted by adults for oviposition
(Schoonhoven et al., 2005). Although the cause for this phenomenon
is unclear, it might be caused by a host prey stimuli that triggers oviposition
of predators (van Driesche and Murray, 2004). Thus, when key
kairomones are lacking in test prey, oviposition on these novel prey is
not likely to occur or may be greatly reduced (van Driesche and
Murray, 2004).
The larval developmental time of a predator is a good indicator of
prey quality, and a slower development is usually expected for prey of
lower quality (van Driesche and Murray, 2004). The results of our host
suitability test showed that the larval development period was similar
among the test prey for C. nipponicus (7.8–9 days) and C. flavocapitis
(8.9–10.67 days). This finding showed that test prey quality was similar
for both predatory beetles. However, the mean life spans of the predatory
beetles varied significantly for the test prey species, which was mainly
attributed to the adult life span. The mean longevity of the adults varied
substantially among the test prey species. Although predators with a
longer life span may indicate an extended predating periods, prey consumption
rate and their fecundity may also need to be considered for
bio-control potential.
In summary, our results showed that the host ranges were similar for
C. nipponicus and C. flavocapitis. These species mainly fed and oviposited
on Diaspididae scale species, and A. yasumatsui is likely to be one of the
most suitable host prey for both beetle species (Bailey et al., 2011). Results
of a field survey revealed that these two beetle species overlapped
on most of the island (Hwang, unpublished data). In addition, Bailey et
al. (2011) indicated that these two beetle species share many similarities,
such as morphology and life demography. Because these two
Cybocephalus beetles share a similar host range, interactions between
them may occur. Future research should focus on the interaction between
these two Cybocephalus beetles and how that interaction may affect
the population dynamics of A. yasumatsui.
Acknowledgment
We thank everyone who contributed to this study. We also thank
the two anonymous reviewers and Roger Haesevoets for their valuable
input to improve the manuscript. This study was funded by the
Forestry Bureau, Council of Agriculture, Executive Yuan, Taiwan.
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