ArticlePDF Available

Species-rich bark and ambrosia beetle fauna (Coleoptera, Curculionidae, Scolytinae) of the Ecuadorian Amazonian Forest Canopy

Authors:

Abstract and Figures

Canopy fogging was used to sample the diversity of bark and ambrosia beetles (Coleoptera, Curculionidae, Scolytinae) at two western Amazonian rainforest sites in Ecuador. Sampling was conducted by Dr Terry Erwin and assistants from 1994–2006 and yielded 1158 samples containing 2500 scolytine specimens representing more than 400 morphospecies. Here, we analyze a subset of these data representing two ecological groups: true bark beetles (52 morphospecies) and ambrosia beetles (69 morphospecies). A high percentage of these taxa occurred as singletons and doubletons and their species accumulation curves did not reach an asymptote. Diversity estimates placed the total scolytine species richness for this taxon subset present at the two sites between 260 and 323 species. The α-diversity was remarkably high at each site, while the apparently high β-diversity was an artifact of undersampling, as shown by a Monte Carlo resampling analysis. This study demonstrates the utility of canopy fogging for the discovery of new scolytine taxa and for approximate diversity assessment, but a substantially greater sampling effort would be needed for conclusive alpha as well as beta diversity estimates.
Content may be subject to copyright.
Species-rich bark and ambrosia beetle fauna
(Coleoptera, Curculionidae, Scolytinae) of the
Ecuadorian Amazonian Forest Canopy
Stephanie A. Dole1, Jiri Hulcr2, Anthony I. Cognato3
1Department of Entomology, California Academy of Sciences 55 Music Concourse Drive, San Francisco, CA
94118, USA 2School of Forest Research and Conservation, University of Florida 136 Newins-Ziegler Hall,
Gainesville, FL 32611, USA 3Department of Entomology, Michigan State University 288 Farm Ln. East
Lansing, MI 48824, USA
Corresponding author: Anthony I. Cognato (cognato@msu.edu)
Academic editor: M. Alonso-Zarazaga|Received 20 August 2020|Accepted 3 October 2020|Published 16 June 2021
http://zoobank.org/D4EB9324-A5B4-48FD-8609-7F260B245010
Citation: Dole SA, Hulcr J, Cognato AI (2021) Species-rich bark and ambrosia beetle fauna (Coleoptera,
Curculionidae, Scolytinae) of the Ecuadorian Amazonian Forest Canopy. In: Spence J, Casale A, Assmann T, Liebherr
JK, Penev L (Eds) Systematic Zoology and Biodiversity Science: A tribute to Terry Erwin (1940–2020). ZooKeys 1044:
797–813. https://doi.org/10.3897/zookeys.1044.57849
Abstract
Canopy fogging was used to sample the diversity of bark and ambrosia beetles (Coleoptera, Curculioni-
dae, Scolytinae) at two western Amazonian rainforest sites in Ecuador. Sampling was conducted by Dr
Terry Erwin and assistants from 1994–2006 and yielded 1158 samples containing 2500 scolytine speci-
mens representing more than 400 morphospecies. Here, we analyze a subset of these data representing
two ecological groups: true bark beetles (52 morphospecies) and ambrosia beetles (69 morphospecies).
A high percentage of these taxa occurred as singletons and doubletons and their species accumulation
curves did not reach an asymptote. Diversity estimates placed the total scolytine species richness for this
taxon subset present at the two sites between 260 and 323 species. e α-diversity was remarkably high
at each site, while the apparently high β-diversity was an artifact of undersampling, as shown by a Monte
Carlo resampling analysis. is study demonstrates the utility of canopy fogging for the discovery of new
scolytine taxa and for approximate diversity assessment, but a substantially greater sampling eort would
be needed for conclusive alpha as well as beta diversity estimates.
Keywords
ambrosia beetles, bark beetles, diversity, neotropical, rainforest, Terry Erwin
ZooKeys 1044: 797–813 (2021)
doi: 10.3897/zookeys.1044.57849
https://zookeys.pensoft.net
Copyright Stephanie A. Dole et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC
BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
SHORT COMMUNICATION
Launched to accelerate biodiversity research
A peer-reviewed open-access journal
Stephanie A. Dole et al. / ZooKeys 1044: 797–813 (2021)
798
Introduction
First pioneered by Southwood (1961) in temperate forests and then later adapted for
tropical research by numerous others (Lowman and Wittman 1996), canopy fogging
methods use insecticide to collect arthropods from the upper architecture of the forest
habitat. ese methods have been used in surveying arthropod diversity, particularly
in lowland rain forests and at several neotropical localities (Erwin 1982; Basset 2001;
Rice 2015). ese data in part were used to make Erwin’s (1982) bold estimate of
30–50 million arthropod species which was a stark contrast to previous estimates of
1.5–10 million (Erwin 1982). Although this provocative publication produced im-
mediate criticism, it initiated focused scientic inquiry for an improved estimate of the
number of worldwide arthropod species (e.g., May 1988; Adis 1990; Gaston 1991;
Erwin 1991; Ødegaard 2000; Hamilton et al. 2010).
For a more than a decade, Erwin and colleagues sampled arthropod diversity in the
Ecuadorian Amazon rainforest canopy at two lowland sites with identied trees, separated
by 21 km of contiguous primary forest, using a standardized insecticidal fogging protocol
(Erwin 1983a, 1983b; Pitman et al. 2001; Erwin et al. 2005). Sampling occurred during
dry, wet, and transitional seasons to measure temporal turnover in species composition.
Over nine million specimens were collected from these fogging events (Rice 2015) and
many new taxa have been described from the specimens (e.g., Erwin 2010).
e Scolytinae (Coleoptera, Curculionidae) is comprised of approximately 257
genera containing 6000 species worldwide (Hulcr et al. 2015). Scolytine species feed
sub-cortically on a wide variety of woody and herbaceous plants. e typical life cycle
of scolytines consists of a brief dispersal ight period after adult emergence, followed
by colonization of new hosts. Once a suitable host has been located, adults bore galler-
ies into the host tissue, where eggs are laid, and larvae complete their development into
the next generation of adults (Kirkendall et al. 2015).
Scolytines are divided into two main ecological groups: bark and ambrosia beetles.
e degree to which scolytines specialize on specic hosts varies considerably depend-
ing on these ecological groups. Bark beetles bore into the phloem of trees, feed on
tree tissues, and tend to have more specialized host preferences. Ambrosia beetles bore
into the xylem, feed on species of symbiotic fungi, which grow along the walls of
their galleries, and tend to have more generalized tree host preferences (Beaver 1979;
Hulcr et al. 2007; Kirkendall et al. 2015). e majority of scolytine diversity occurs
in tropical regions of the world, and many tropical species remain undescribed (Wood
2007; Hulcr et al. 2015; Smith et al. 2017). e Ecuadorian canopy fogging samples
collected in Erwin’s surveys oer a rich source of new scolytine specimens because of
observed scolytine species specialization to tree taxa, tree parts, and other microclimate
factors (e.g., Hulcr et al. 2007; Kirkendall et al. 2015). In addition, only fewer than
200 species have been recorded for Ecuador (Wood 2007; Martínez et al. 2019; Jordal
and Smith 2020), but the Ecuadorian species richness is likely underestimated given
the continuous discovery of new species (e.g., Petrov and Flechtmann 2013; Petrov
and Mandelshtam 2018; Smith and Cognato, in prep.).
Scolytine Amazonian canopy diversity 799
Remarkably few studies have addressed the spatial and temporal turnover of sco-
lytine species (β-diversity) (Deyrup and Atkinson 1987; unes 1998; Peltonen et
al. 1998; Hulcr et al. 2008a, b). e majority of studies have focused on the com-
position of the scolytine fauna of temperate regions and examined the distributions
of a few economically important species (Deyrup and Atkinson 1987; Jakus 1998;
Peltonen et al. 1998; Oliver and Mannion 2001; Gaylord et al. 2006). Several stud-
ies in the tropics have attempted to determine the eects of seasonal changes in
rainfall and temperature on the composition of scolytine communities (Beaver and
Löyttyniemi 1991; Madoe and Bakke 1995; Morales et al. 2000; Flechtmann et
al. 2001; Hulcr et al. 2008a; Sandoval Rodríguez et al. 2017; Martinez et al. 2019;
Sanguansub et al. 2020). Studies in Malaysian forests have examined the spatial dis-
tribution of scolytines across horizontal (Maeto et al. 1999; Chung 2004) and ver-
tical gradients (Maeto and Fukuyama 2003; Simon et al. 2003). Recent studies in
ailand (Hulcr et al. 2008a; Sanguansub et al. 2020) and Papua New Guinea (Hulcr
et al. 2008b) have used quantitative sampling to examine scolytine community com-
position and attempt to determine the proximate causes of the distribution of species
in tropical habitats. Scolytine communities in lowland homogeneous Papua New
Guinean rainforests have a low β-diversity, thus contradicting the expected trend
of high β-diversity in the tropics. Novotny et al. (2007) similarly demonstrated low
species turnover for insect communities when examined on a large scale across Papua
New Guinea. In ailand, two study sites separated by only 5 km were found to have
signicantly dierent scolytine species composition (Hulcr et al. 2008a), however the
dierences were attributed to dierences in forest type, elevation, seasonality, mean
annual temperature and humidity (Hulcr et al. 2008a; Sanguansub et al. 2020). Giv-
en the scenarios above, it is uncertain whether Amazonian forests will produce the
same trend of low β-diversity seen in Papua New Guinea or high β-diversity, as was
observed between dierent ai forests.
In tropical ecosystems, an increase in host specicity combined with an increase
in plant diversity is often used to explain high levels of species diversity. However,
bark and ambrosia beetles show a reverse trend with at least some groups exhibiting
lower host specicity in tropical regions. is is largely due to the greater abundance
of ambrosial feeding scolytines which, as discussed above, tend to be relative host plant
generalists (Beaver 1979), with high symbiont specicity. Nevertheless, most scolyt-
ine groups have higher species diversity in tropical regions than they do in temperate
ones (Beaver 1979; Deyrup and Atkinson 1987; Hulcr et al. 2015). It is therefore
expected that canopy fogging will yield a high number of scolytine species, but that
the β-diversity of scolytines across the Amazonian canopy may not necessarily be high.
In this study, we use a subset of scolytine specimens representing both the bark
beetle and ambrosia beetle ecological groups to assess the diversity of scolytines at two
western Amazonian forest study sites. We use these data to assess the value of canopy
fogging as a source of scolytine specimens, determine the spatial turnover of scolytine
species, and use the data collected from these fogging stations to predict the scolytine
species richness at the two sites.
Stephanie A. Dole et al. / ZooKeys 1044: 797–813 (2021)
800
Materials and methods
Field sites and sampling
e two study sites in this investigation were typical lowland rain forest habitats in
the western Amazon Basin at the margin of Yasuní National Park, separated by 21 km
of contiguous primary forest: Onkone Gare Station (cited as “Pirañain Pitman et al.
2001 and Erwin et al. 2005) (0°39'25.685"S, 76°217'10.813"W; 216 m) and Tiputini
Biodiversity Station (0°37'55.397"S, 76°08'39.205"W; 216 m). e Onkone Gare
and Tiputini study plots were established in 1994 and 1997, respectively. e study
sites receive an average of 2.7 m of rainfall per year (Erwin et al. 2005). Precipitation at
the two sites is seasonal, with the wet season occurring from May to October and the
dry season occurring from November to April.
Tree data were recorded for collecting stations within Erwin’s canopy fogging study
transects. Trees with a diameter at breast height (diameter measured at 1.33 m from
tree base) greater than 10 cm that had at least part of a branch hanging over the col-
lecting sheet were tagged by Erwin’s team and subsequently identied (Pitman et al.
2001). In terms of trees, the Onkone Gare and Tiputini sites are very dierent at the
species level (73% occurring at only one site), moderately dissimilar at the generic level
(53% occurring at only one site), and fairly similar at the family level (26% occurring
at only one site). With approximately 250 species each, the two study sites represent
individually 21.26% (Onkone Gare) and 21.42% (Tiputini) and collectively 34% of
the regional tree diversity (Erwin et al. 2005).
e fogging protocol followed Erwin (1983a, b). e study plot area at each site
(100 m × 1000 m) was divided into 10 transects (10 m × 100 m). Each transect con-
sisted of 10 collecting stations, catches for falling arthropods (3 m × 3 m), which were
randomly arrayed on both sides of the transect centerline. Each station was constructed
of a sampling sheet tied, suspended 1 m o the ground, and xed with a collecting jar
attached to the center of the sheet. e total area of these collecting stations was 9250
m2, which represented just 1.11% of the entire transect at each site.
Fogging occurred at Onkone Gare from 1994–1996 and 2005–2006, and at Ti-
putini from 1998–2002 three times per year: January/February (dry), June/July (wet),
and October (transitional). Foggings occurred at 0345–0500 hr in order to minimize
insecticidal drift outside of the column due to air currents. e pyrethroid insecticide
resmythrim was fogged for 60 seconds in a column from just above the sheet to a
height that was then recorded for each fogging event (for details on fogging techniques
and equipment used see Lucky et al. 2002). Previous studies demonstrated that arthro-
pod repopulation occurs within 10 days after fogging (Lucky et al. 2002). Hence, the
same stations could be resampled seasonally without an eect on sampling.
e samples examined herein represent only a subset (1158 samples) of the total
(1400+ samples) taken during the decade of canopy fogging. Samples from several
collecting expeditions were not exported from Ecuador and were therefore not avail-
able for this study. Scolytine beetles were extracted from the adult Coleoptera samples,
Scolytine Amazonian canopy diversity 801
sorted to morphospecies, and identied using published keys (e.g., Wood 2007). For
this study, subset of scolytine specimens representing both the bark beetle (Bothros-
ternini, Phloeosinini, Phloeotribini, Phrixosomini) and ambrosia beetle (Xyleborini,
Ipini: Premnobius) were included for the diversity assessments. We excluded the Cor-
thylini, Trypophloeini, Hexacolini and other former Cryphalini, and Scolytini because
of potential ination of the diversity estimates due to sexual dimorphism and cryptic
species boundaries.
Analysis of communities
We compared the dierences between the communities of scolytines occurring at
Onkone Gare and Tiputini with statistical analyses used in similar studies (Hulcr et al.
2008a, b). All calculations were performed with the EstimateS software (Colwell 2004).
Accumulation curves of species richness were estimated using the Mao Tau
function which is an analytical analog of a randomized rarefaction procedure. Im-
pact of rare species on these accumulation curves was evaluated with abundance-
based, Chao1 (Chao 1984) and the Abundance-based Coverage Estimator (ACE)
(Chao and Lee 1992; Chao et al. 1993), and incidence-based, Chao2 (Chao 1987)
and the Incidence-based Coverage Estimator (ICE) (Lee and Chao 1994), richness
estimators. ACE and ICE considered two classes of species for their calculations:
those that are rare and those that are not rare. For analytical purposes, ACE and
ICE considered species with fewer than 10 individuals in the sample to be rare (the
default setting in EstimateS Colwell 2004). Chao1 and Chao2 treat all species (rare
and not rare) the same in their calculations. ese calculations also estimate the
eect of unseen rare species (rare species that were not sampled). e default bias-
corrected option was used to calculate Chao1 and Chao2. is analysis estimated
the critical value for the abundance distribution as > 0.5 for all subsets of the data
analyzed. In cases such as these the recalculation of the Chao1, Chao2, ACE, and
ICE using the Classic option is recommended. us, the richness estimators re-
ported herein were calculated using the Classic option under diversity settings in
EstimateS (Colwell 2004).
In addition to the above richness estimators, a second-order Jackknife (Burnham
and Overton 1978, 1979) was calculated. is measure is based on the number of
species that occur in one sample, as well as those that occur in exactly two samples.
Colwell and Coddington (1994) have shown the second-order Jackknife to be one of
the more reliable predictors of species diversity.
Faunal distinctness or dissimilarity between the two sites was measured with the
Complementarity Index (CI) (Colwell and Coddington 1994). is calculation is
based on the observed species for each sample, the total species richness, and the num-
ber of species unique to either sample. Complementarity Index value of 1 indicates
that compared samples do not share any species in common. Complementary indices
were calculated for each taxon, as well as for the ambrosia beetles, bark beetles, and for
the total sample (all beetles) for Onkone Gare and Tiputini. In addition, for the total
Stephanie A. Dole et al. / ZooKeys 1044: 797–813 (2021)
802
sample, we used the Chao-Sørensen abundance-based estimator which corrects for
biases of incomplete samples of the fauna by incorporating the eect of unseen shared
species (Chao et al. 2005, 2006). Given that the Onkone Gare study site was sampled
more than twice as much as the Tiputini site (311 lots versus 115 lots, respective), we
rareed the data for the Chao-Sørensen analysis. A lognormal distribution was used for
rarefaction resulting in a Tiputini mean (SD) = 1.93 (12.21) and a Onkone Gare mean
(SD) = 1.93 (12.70)]. e total number of individual specimens for both the Tiputini
and the Onkone Gare rareed samples equaled 230.
To test the hypothesis that the observed similarity is not statistically signicant,
but rather a result of random sampling of individuals from similar or identical scolyt-
ine communities, we performed a Monte Carlo analysis using the total rareed dataset.
In each replicate of this test individuals of each species were randomly distributed
between the two sites. is randomized dataset was then used to calculate the Chao-
Sørensen similarity index and the procedure was repeated 100 times.
Results
A total of 1158 canopy fogging bulk samples were analyzed from the Ecuadorian Ama-
zon study transects; 965 from Onkone Gare and 293 from the Tiputini (Table 1).
Scolytines were found in 60% of the Onkone Gare samples, 75% of the Tiputini
samples, and 69% of the total samples from both sites. ese samples contained a
total of 2500 scolytines, representing more than 400 morphospecies including a large
number of rare species occurring as singletons and doubletons. e subset of taxa
examined here represented 688 individuals and 121 species (Tables 2, 3). e bark
beetles (Bothrosternini, Phloeosinini, Phloeotribini, and Phrixosomini) totaled 183
specimens representing 9 genera and 52 morphospecies (Tables 2, 4). e ambrosia
beetles (Xyleborini, and Premnobiina) totaled 504 specimens representing nine genera
and 70 species (Tables 3, 4).
Table 1. Numbers of scolytine species from canopy fogging two sites in Ecuador, complimentary index
values and species richnessestimates. CI= complimentary index, ACE= Abundance-based Coverage Esti-
mator, ICE= Incidence-based Coverage Estimator, Jack2 = second-order jackknife.
(A) All taxa No. Samples Species
Observed
Unique
Species
CI ACE ICE Chao1 Chao2 Jack2
Onkone Gare 965 98 74 NA 275 292 296 309 217
Tiputini 293 47 24 NA 90 96 85 90 95
Both Sites 1158 121 NA 0.81 301 323 308 311 260
(B) Bark beetles
Onkone Gare 965 42 32 NA 95 90 154 109 83
Tiputini 293 20 10 NA 38 35 32 30 35
Both Sites 1158 52 NA 0.81 121 119 154 137 109
(C) Ambrosia beetles
Onkone Gare 965 56 42 NA 179 184 153 208 128
Tiputini 293 27 14 NA 51 61 55 67 58
Both Sites 1158 69 NA 0.81 183 211 161 174 150
Scolytine Amazonian canopy diversity 803
Table 2. Numbers of bark beetle species collected at two sites in Ecuador.
Subtribe Genus Species Locality(ies) No. Specimens
Bothrosternini Akrobothrus ecuadoriensis Onkone Gare 3
Bothrosternus n. sp. nr. truncatus Onkone Gare/Tiputini 8
sp. 1 Tiputini 1
sp. 2 Onkone Gare 1
sp. 3 Onkone Gare 1
sp. 4 Onkone Gare 1
Cnesinus sp. 1 Onkone Gare 4
sp. 2 Onkone Gare 6
sp. 3 Tiputini 1
sp. 4 Tiputini 2
sp. 5 Tiputini 2
sp. 6 Onkone Gare/Tiputini 4
sp. 7 Onkone Gare/Tiputini 4
sp. 8 Onkone Gare 1
sp. 9 Onkone Gare/Tiputini 5
sp. 10 Onkone Gare 1
Eupagiocerus sp. 1 Onkone Gare/Tiputini 2
Pagiocerus sp. 1` Onkone Gare/Tiputini 4
Sternobothrus sp. 1 Tiputini 2
sp. 2 Onkone Gare 1
sp. 3 Onkone Gare 1
sp. 4 Onkone Gare 1
Phloeosinini Chramesus sp. 1 Onkone Gare 1
sp. 2 Tiputini 1
sp. 3 Onkone Gare 1
sp. 4 Tiputini 1
sp. 5 Onkone Gare 1
sp. 6 Onkone Gare 1
Phloeotribini Phloeotribus sp. 1 Onkone Gare/Tiputini 31
sp. 2 Onkone Gare 20
sp. 3 Onkone Gare/Tiputini 6
sp. 4 Onkone Gare/Tiputini 21
sp. 5 Onkone Gare 1
sp. 6 Onkone Gare 4
sp. 7 Onkone Gare 1
sp. 8 Onkone Gare 1
sp. 9 Onkone Gare 2
sp. 10 Onkone Gare 1
sp. 11 Onkone Gare 1
sp. 12 Tiputini 2
sp. 13 Onkone Gare 1
sp. 14 Tiputini 1
sp. 15 Onkone Gare/Tiputini 7
sp. 16 Onkone Gare 13
sp. 17 Onkone Gare 1
sp. 18 Tiputini 1
sp. 19 Onkone Gare 1
sp. 20 Onkone Gare 1
sp. 21 Onkone Gare 1
Phrixosomini Phrixosoma sp. 1 Onkone Gare 1
sp. 2 Onkone Gare 1
sp. 3 Onkone Gare 1
183
Stephanie A. Dole et al. / ZooKeys 1044: 797–813 (2021)
804
Table 3. Numbers of ambrosia beetle species collected at two sites in Ecuador.
Subtribe Genus Species Locality(ies) No. Specimens
Xyleborini Ambrosiodmus sp. Onkone Gare 1
Callibora sarahsmithae Onkone Gare 1
Coptoborus sp. 1 Onkone Gare/Tiputini 6
sp. 2 Onkone Gare 1
sp. 3 Onkone Gare 2
sp. 4 Onkone Gare/Tiputini 15
sp. 5 Onkone Gare/Tiputini 11
sp. 6 Onkone Gare/Tiputini 2
sp. 7 Tiputini 1
sp. 8 Onkone Gare/Tiputini 2
sp. 9 Onkone Gare/Tiputini 5
sp. 10 Onkone Gare/Tiputini 6
sp. 11 Onkone Gare 1
sp. 12 Onkone Gare 1
sp. 13 Onkone Gare 1
sp. 14 Onkone Gare 1
sp. 15 Onkone Gare 1
sp. 16 Onkone Gare 1
sp. 17 Onkone Gare 3
sp. 18 Onkone Gare 1
sp. 19 Onkone Gare 1
sp. 20 Onkone Gare 1
sp. 21 Onkone Gare 1
sp. 22 Tiputini 1
sp. 23 Onkone Gare 1
sp. 24 Onkone Gare 1
sp. 25 Onkone Gare 2
vespatorius Onkone Gare 1
Dryocoetoides sp. 1 Onkone Gare 6
sp. 2 Onkone Gare 1
sp. 3 Onkone Gare 1
sp. 4 Onkone Gare 1
sp. 5 Onkone Gare 2
eoborus sp. 1 Tiputini 1
sp. 2 Tiputini 3
sp. 3 Onkone Gare/Tiputini 5
nr. micarius Onkone Gare 1
sp. 4 Onkone Gare 3
sp. 5 Tiputini 1
sp. 6 Onkone Gare/Tiputini 8
sp. 7 Tiputini 1
sp. 8 Onkone Gare 1
sp. 9 Onkone Gare 1
sp. 10 Onkone Gare 1
Xyleborinus sp. 1 Tiputini 2
Xyleborus sp. 1 Tiputini 21
spathipennis Onkone Gare/Tiputini 2
anis Onkone Gare/Tiputini 317
sp. 2 Tiputini 1
nr. ferrugineus Onkone Gare/Tiputini 12
sp. 3 Onkone Gare 2
Scolytine Amazonian canopy diversity 805
Subtribe Genus Species Locality(ies) No. Specimens
Xyleborini Xyleborus sp. 4 Tiputini 8
sp. 5 Tiputini 1
sp. 6 Onkone Gare 1
sp. 7 Tiputini 1
sp. 8 Tiputini 1
sp. 9 Onkone Gare 1
sp. 10 Onkone Gare 2
sp. 11 Tiputini 1
sp. 12 Onkone Gare 1
sp. 13 Onkone Gare 1
sp. 14 Onkone Gare 2
sp. 15 Onkone Gare 1
sp. 16 Onkone Gare 1
sp. 17 Onkone Gare 1
sp. 18 Onkone Gare 1
sp. 19 Onkone Gare 1
Xylosandrus morigerus Onkone Gare/Tiputini 12
Premnobiina Premnobius cavipennis Onkone Gare 1
Total 504
Table 4. South American (SA) scolytine genera and species recorded and collected via canopy fogging.
Taxon SA Genera SA Species Genera Collected Species Collected
Xyleborini 11 233 8 69
Premnobiina 2 4 1 1
Bothrosternini 6 82 6 22
Phloeosinini 5 61 1 6
Phloeotribini 1 54 1 21
Phrixosomini 1 10 1 3
Species accumulation curves for both sites combined and for each site individually
did not reach an asymptote (Fig. 1). e steady increase of the curves indicated a contin-
ued accumulation of rare species (singletons and doubletons). Estimates of species rich-
ness were very similar between abundance-based and incidence-based statistics (Table
1; Fig.1). For the two sites combined, the abundance-based ACE and Chao1 estimated
a total species richness of 301 and 308 species, respectively. e incidence-based ICE
and Chao2 gave marginally higher estimates. Abundance-based and incidence-based
estimates of species richness for the Onkone Gare overlapped slightly with 275–309
species. Abundance-based and incidence-based (Chao1) statistics arrived at similar es-
timates and the incidence-based statistics, ICE and Chao2 estimated a slightly greater
species diversity for the Tiputini site. e second-order Jackknife estimated a species
richness of 260 species for both study sites (Table 1; Fig. 1). For Onkone Gare, the
second-order Jackknife estimated 217 species and for Tiputini it estimated 95 species.
Simple Complementarity Indices suggested that the composition of the scolytine
fauna was markedly dierent for the two study sites. Onkone Gare and Tiputini had a
CI = 0.81 for the total analyzed subset of scolytine tribes (Table 1). Complementarity
Indices for the tribes ranged from 0.73 to 1.00 (although a CI=1 for Premnobiina is
Stephanie A. Dole et al. / ZooKeys 1044: 797–813 (2021)
806
meaningless because only one specimen was collected) (Table 5). In the samples, at
least half of all the species occurring at either site was unique to that site: 76% of spe-
cies at Onkone Gare and 50% or species at Tiputini (Table 1).
However, the correction for biases of incomplete sampling of the fauna using the
Chao-Sørensen abundance-based estimator with the rareed data estimated a faunal
similarity of 0.79. Similarly, the Monte Carlo analysis returned a probability of 0.374
[median modeled similarity L’ = 0.77 (lower and upper 2.5% quantiles = 0.634 and
0.836)]. Both the Chao-Sørensen and the Monte Carlo analyses indicate that the ap-
parent dierence between the two sites was due to stochastic sampling error and the
dierence does not appear to be biologically signicant.
Figure 1. A species accumulation curves for Onkone Gare B species accumulation curves for Tiputini
Cspecies richness estimators for Onkone Gare D species richness estimators for Tiputini E species accu-
mulation curves for both sites combined F species richness estimators for both sites combined.
Scolytine Amazonian canopy diversity 807
Discussion
e goals of this study were to assess the scolytine species richness, the use of canopy
fogging to enhance the discovery of new taxa, and to estimate the faunal turnover
(β-diversity) between a short distance in Amazonian rain forest. Species records for
Ecuador range from 50 recorded in a monograph (Wood 2007) to 85 collecting at one
site over a year (Martinez et al. 2019) and 248 have been recorded for Peru (Smith et al.
2017). Our entire collection of scolytines from the fogging represents 400 morphospe-
cies out of 2500 specimens. is species richness is proportionally 30x greater than the
species richness recorded for a western Ecuadorian forest (85 species out of ~18,000
specimens). Given the estimates of species richness suggest nearly twice the number
of species in only these eld sites (Tables 2, 3) and the diversity and long stability of
Ecuadorian forest habitats (McKenna and Farrell 2006), it is likely the actual scolytine
diversity exceeds 400 species.
Taxonomic study of these 400 morphospecies has yielded species descriptions of
21 Scolytodes species (84% of the known Ecuadorian fauna) (Jordal and Smith 2020),
seven Camptocerus species (39% of the known Ecuadorian fauna) (Smith and Cognato
2010), and 15 Coptoborus (45% of the known Ecuadorian fauna) (Smith and Cognato,
in prep.). In addition, faunal discoveries include descriptions of new genera with strik-
ing morphologies: Akrobothrus Dole & Cognato, 2007 and Callibora Cognato, 2018.
ese discoveries suggest that canopy fogging is not only a useful method for the col-
lection of known scolytine fauna, but it is also a mean to access a poorly explored fauna.
Our analysis of the partial scolytine samples fogged from the Ecuadorian Amazo-
nian canopy indicates a species-rich fauna but the estimate of a high β-diversity de-
pended on the method’s sensitivity to undersampling. Specically, the simple measure
of complementarity suggested substantial faunal dierence between the sites, but the
Chao-Sørensen and Monte Carlo resampling showed that the dierences were statisti-
cally inconclusive.
Our results indicate that even a large-scale, long-term sampling eort, such as
this one, did not provide a reliable estimate of scolytine diversity for the two western
Amazonian sites. Despite over 1100 individual fogging events (representing 14 fogging
expeditions), which collected 688 individual beetles representing 121 species (used in
this analysis), the species accumulation curves did not reach an asymptote (Fig. 1).
Likewise, the accumulation of rare species in the form of singletons and doubletons
Table 5. Distribution of species by taxon between sites and the corresponding index values.
Taxon % Occurrence in
Samples
Onkone Gare
spp.
Tiputini
spp.
Total
spp.
Shared
spp.
Unique
spp.
CI
Xyleborini 27 56 27 69 14 55 0.81
Premnobiina 0.09 1 0 1 0 1 1.00
Bothrosternini 4.32 17 11 22 6 16 0.73
Phloeosinini 0.52 4 2 6 0 6 1.00
Phloeotribini 7.69 18 7 21 4 17 0.81
Phrixosomini 0.26 3 0 3 0 3 1.00
Stephanie A. Dole et al. / ZooKeys 1044: 797–813 (2021)
808
did not decline. ese phenomena were observed from the individual data collected for
each study transect and for the collective species data for the two sites.
Despite this inconclusive result, we speculate on the scolytine diversity in the
canopy. Given the relatively short distance (21 km) between Onkone Gare and Tipu-
tini the real β-diversity is likely low because of the sites’ relatively proximity and very
similar environment. e Onkone Gare and Tiputini sites dier in the occurrence of
tree species but share the same tree families (Erwin et al. 2005). Bark and ambrosia
beetle’s tree host specicity usually occurs at the family level (Beaver 1979) thus pre-
dicting low β-diversity between these sites. Conversely, previous canopy fogging stud-
ies have found signicant dierences in the beetle species composition of dierent
forest types. In Manaus, Brazil, 83% of beetle species in canopy fogging samples were
found in only one type of forest (Erwin 1983a). Of the four forest types characterized
and studied by Erwin, “mixed-water” forests were found to be the most species rich.
However, “terra rme” (non-oodplain) forests had the second highest number of
species and the highest number of restricted species. Both sites sampled in this study
were “terra rme” forest. Erwin also found that smaller insect species (1 mm class, as
dened for his study) comprise the majority of insects in “terra rmeforests. is
oers another predictor of scolytine diversity in this habitat, as most scolytine species
are within the 1–3 mm range. If scolytines follow the same general patterns found for
all Amazonian insects, we can predict that further sampling would uncover an even
richer scolytine fauna with possibly many species not found in other forest types.
e high percentage of singletons and doubletons at each site supports this predic-
tion. Conversely, increased sampling may yield more specimens of rare species which
would decrease β-diversity.
Large-scale sampling of tropical habitats oers a rich source of previously un-
known species, but as this study demonstrates, even the most ambitious sampling
schemes may not be enough to adequately assess the true species richness of hyper-
diverse groups. Here we have uncovered a level of scolytine α-diversity that increases
the known fauna of Ecuador nearly ve-fold, only based on sampling a single Amazo-
nian habitat. Future studies will need even more extensive sampling protocols to avoid
erroneous conclusions and over-estimates of β-diversity based on stochastic sampling
(Hulcr et al. 2007; Lewinsohn and Roslin 2008).
Acknowledgements
e authors are grateful to Dr Terry Erwin for his collaboration and generous shar-
ing of samples that made this work possible. roughout his distinguished career Dr
Erwin was known for his warm and enthusiastic demeanor and his mentorship of
students from around the world. SAD was one such graduate student and considers
working beside Terry canopy fogging in the Ecuadorian Amazon to be one of the rich-
est experiences of her career. Dr Erwin lives on in his substantial body of work and in
the careers of the many scientists he mentored. We would like to thank Sarah Smith
Scolytine Amazonian canopy diversity 809
(Michigan State University) for her assistance and support with this research. Speci-
men collection funded by: Ecuambiente Consulting Group, Ecuador; Casey Fund,
Department of Entomology, NMNH; NMNH Lowland Amazon Project. is re-
search was supported by NSF-PEET grant (DEB-0328920) to Anthony I. Cognato
(Michigan State University).
References
Adis J (1990) irty million arthropod species – too many or too few? Journal of Tropical Ecol-
ogy 6: 115–118. https://doi.org/10.1017/S0266467400004107
Basset Y (2001) Invertebrates in the canopy of tropical rain forests. How much do we really
know? Plant Ecology 153: 87–107. https://doi.org/10.1007/978-94-017-3606-0_8
Beaver RA (1979) Host specicity of temperate and tropical animals. Nature 281: 139–141.
https://doi.org/10.1038/281139a0
Beaver RA, Löyttyniemi K (1991) Annual ight patterns and diversity of bark and ambrosia
beetles (Col., Scolytidae and Platypodidae) attracted to bait logs in Zambia. Journal of Ap-
plied Entomology 112: 505–511. https://doi.org/10.1111/j.1439-0418.1991.tb01084.x
Burnham KP, Overton WS (1978) Estimation of the size of a closed population when capture
probabilities vary among animals. Biometrika 65: 623–633. https://doi.org/10.1093/bi-
omet/65.3.625
Burnham KP, Overton WS (1979) Robust estimation of population size when capture prob-
abilities vary among animals. Ecology 60: 927–936. https://doi.org/10.2307/1936861
Chao A (1984) Non-parametric estimation of the number of classes in a population. Scandina-
vian Journal of Statistics 11: 265–270.
Chao A (1987) Estimating the population size for capture-recapture data with unequal catch-
ability. Biometrics 43: 783–791. https://doi.org/10.2307/2531532
Chao A, Chazdon RL, Colwell RK, Shen T-J (2005) A new statistical approach for assessing
similarity of species composition with incidence and abundance data. Ecology Letters 8:
148–159. https://doi.org/10.1111/j.1461-0248.2004.00707.x
Chao A, Chazdon RL, Colwell RK, Shen T-J (2006) Abundance-based similarity indicies and
their estimation when there are unseen species in samples. Biometrics 62: 361–371. htt-
ps://doi.org/10.1111/j.1541-0420.2005.00489.x
Chao A, Lee SM (1992) Estimating the number of classes via sample coverage. Journal of
American Statistical Association 87: 210–217. https://doi.org/10.1080/01621459.1992.
10475194
Chao A, Ma MC, Yang MCK (1993) Stopping rules and estimation for recapture debugging with
unequal failure rates. Biometrika 80: 193–201. https://doi.org/10.1093/biomet/80.1.193
Chung AYC (2004) Vertical stratication of beetles (Coleoptera) using ight intercept traps in
a lowland rainforest of Sabah, Malaysia. Sepilok Bulletin 1: 27–39.
Cognato AI (2018) Callibora, Cognato, a new genus of xyleborine ambrosia beetle (Curcu-
lionidae: Scolytinae: Xyleborini) from Ecuador. e Coleopterists Bulletin 72: 801–804.
https://doi.org/10.1649/0010-065X-72.4.801
Stephanie A. Dole et al. / ZooKeys 1044: 797–813 (2021)
810
Colwell RK (2004) EstimateS: Statistical estimation of species richness and shared species from
samples. Version 7.5. User’s Guide and application e-published. http://viceroy.eeb.uconn.
edu/estimates
Colwell RK, Coddington JA (1994) Estimating terrestrial biodiversity through extrapolation.
Philosophical Transactions of the Royal Society of London, Series B 345: 101–118. https://
doi.org/10.1098/rstb.1994.0091
Deyrup M, Atkinson TH (1987) Comparative biology of temperate and subtropical bark and
ambrosia beetles (Coleoptera: Scolytidae, Platypodidae) in Indiana and Florida. e Great
Lakes Entomologist 20(2): 59–66.
Dole SA, Cognato AI (2007) A New Genus and Species of Bothrosternina (Coleoptera; Curcu-
lionidae: Scolytinae) from Ecuador. e Coleopterists’ Bulletin 61: 318–325. https://doi.
org/10.1649/0010-065X(2007)61[318:ANGASO]2.0.CO;2
Erwin TL (1982) Tropical forests: their richness in Coleoptera and other arthropod species.
Coleopterists’ Bulletin 36(1): 74–75.
Erwin T L (1983a) Tropical forest canopies, the last biotic frontier. Bulletin of the Entomologi-
cal Society of America 29(1): 14–19. https://doi.org/10.1093/besa/29.1.14
Erwin TL (1983b) Beetles and other arthropods of the tropical forest canopies at Manaus, Bras-
il, sampled with insecticidal fogging techniques, . In: Sutton SL, Whitmore TC, Chadwick
AC (Eds) Tropical Rain Forests: Ecology and Management. Blackwell Scientic Publica-
tions, Oxford, 59–75.
Erwin TL (1991) How many species are there?: Revisited. Conservation Biology 5: 330–333.
https://doi.org/10.1111/j.1523-1739.1991.tb00145.x
Erwin TL, Pimienta MC, Murillo OE, Aschero V (2005) Mapping Patterns of ß-Diversity for
Beetles Across the Western Amazon Basin: A Preliminary Case for Improving Inventory
Methods and Conservation Strategies. Proceedings of the California Academy of Sciences,
ser. 4 56(Suppl. I): 72–85.
Erwin TL (2010) Agra, arboreal beetles of Neotropical forests: pusilla group and piranha
group systematics and notes on their ways of life (Coleoptera, Carabidae, Lebiini, Agrina).
ZooKeys 66: 1–28. https://doi.org/10.3897/zookeys.66.684
Flechtmann, CAH, Ottati ALT, Berisford CW (2001) Ambrosia and bark beetles (Scolytidae:
Coleoptera) in pine and ecalypt stands in southern Brazil. Forest Ecology and Management
142: 183–191. https://doi.org/10.1016/S0378-1127(00)00349-2
Gaston KJ (1991) e magnitude of global insect species richness. Conservation Biology
5(3):283–296. https://doi.org/10.1111/j.1523-1739.1991.tb00140.x
Gaylord ML, Kolb TE, Wallin KF, Wagner MR (2006) Seasonality and lure preference of bark
beetles (Curculionidae: Scolytinae) and associates in a Northern Arizona ponderosa pine for-
est. Environmental Entomology 35: 37–47. https://doi.org/10.1603/0046-225X-35.1.37
Hamilton AJ, Basset Y, Benke KK, Grimbacher PS, Miller SE, Novotny V, Samuelson GA, Stork
NE, Weiblen GD, Yen JDL (2010) Quantifying Uncertainty in Estimation of Tropical Arthro-
pod Species Richness. e American Naturalist 176: 90–95. https://doi.org/10.1086/652998
Hulcr J, Mogia M, Isua B, Vojtech N (2007) Host specicity of ambrosia and bark beetles
(Col., Curculionidae: Scolytinae and Platypodinae) in a New Guinea rainforest. Ecological
Entomology 32: 762–772. https://doi.org/10.1111/j.1365-2311.2007.00939.x
Scolytine Amazonian canopy diversity 811
Hulcr J, Beaver RA, Puranaskul W, Dole SA, Sonthichai, S (2008a) A comparison of bark and
ambrosia beetle communities in two forest types in Northern ailand (Coleoptera: Cur-
culionidae: Scolytinae and Platypodinae). Environmental Entomology 37: 1461–1470.
https://doi.org/10.1603/0046-225X-37.6.1461
Hulcr J, Novotny V, Maurer BA, Cognato AI (2008b) Low beta diversity of ambrosia bee-
tles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) in lowland rainforests
of Papua New Guinea. Oikos 117: 214–222. https://doi.org/10.1111/j.2007.0030-
1299.16343.x
Hulcr J, Atkinson TH, Cognato AI, Jordal BH, McKenna DD (2015) Morphology, Taxonomy
and Phylogenetics of Bark Beetles. In: Vega FE, Hofstetter RW (Eds) Bark Beetles. Biology
and Ecology of Native and Invasive Species. Academic Press, London, 41–84. https://doi.
org/10.1016/B978-0-12-417156-5.00002-2
Jakus R (1998) Patch level variation on bark beetle attack (Col., Scolytidae) on snapped
and uprooted trees in Norway spruce primeval natural forest in endemic conditions:
species distribution. Journal of Applied Entomology 122 (2–3): 65–70. https://doi.
org/10.1111/j.1439-0418.1998.tb01463.x
Jordal BH, Smith SM (2020) Scolytodes Ferrari (Coleoptera, Scolytinae) from Ecuador: 41 new
species, and a molecular phylogenetic guide to infer species boundaries. Zootaxa. https://
doi.org/10.11646/zootaxa.4813.1.1 [In press]
Kirkendall LR, Biedermann PHW, Jordal BH (2015) Evolution and diversity of bark and am-
brosia beetles. In: Vega FE, Hofstetter RW (Eds) Bark Beetles. Biology and Ecology of
Native and Invasive Species. Academic Press, London, 85–156. https://doi.org/10.1016/
B978-0-12-417156-5.00003-4
Lee SM, Chao A (1994) Estimating population size via sample coverage for closed capture-
recapture models. Biometrics 50: 88–97. https://doi.org/10.2307/2533199
Lewinsohn TM, Roslin T (2008) Four ways toward tropical herbivore megadiversity. Ecological
Letters 11: 398–416. https://doi.org/10.1111/j.1461-0248.2008.01155.x
Lowman MD, Wittman PK (1996) Forest Canopies: Methods, Hypotheses, and Future Direc-
tions. Annual Review of Ecology and Systematics 27: 55–81. https://doi.org/10.1146/
annurev.ecolsys.27.1.55
Lucky A, Erwin TL, Witman JD (2002) Temporal and Spatial Diversity and Distribution of
Arboreal Carabidae (Coleoptera) in a Western Amazonian Rain Forest. Biotropica 34(3):
376–386. https://doi.org/10.1111/j.1744-7429.2002.tb00551.x
Madoe SS, Bakke A (1995) Seasonal uctuations and diversity of bark and wood-boring
beetles in lowland forest: implications for management practice. South African Forestry
Journal 173: 9–15. https://doi.org/10.1080/00382167.1995.9629684
Maeto K, Fukuyama K (2003) Vertical stratication of ambrosia beetle assemblages in a lowland
forest at Pasoh, peninsular Malaysia. In: Okuda T, Manokaran N, Matsumoto Y, Niiyama
K, omas SC, Ashton PS (Eds) Pasoh: Ecology of a Lowland Rain Forest in Southeast
Asia. Springer, Tokyo, 325–336. https://doi.org/10.1007/978-4-431-67008-7_24
Maeto K, Fukuyama K, Kirton LG (1999) Edge eects on ambrosia beetle assemblages in a
lowland forest, bordering oil palm plantations in peninsular Malaysia. Journal of Tropical
Forest Science 11: 537–547.
Stephanie A. Dole et al. / ZooKeys 1044: 797–813 (2021)
812
Martínez M, Cognato AI, Guachambala M, Boivin T (2019). Bark and ambrosia beetle (Co-
leoptera: Curculionidae: Scolytinae) diversity in natural and plantation forests in Ecuador.
Environmental Entomology 48: 603–613. https://doi.org/10.1093/ee/nvz037
McKenna DD, Farrell BD (2006) Tropical forests are both evolutionary cradles and muse-
ums of leaf beetle diversity. Proceedings of the National Academy of Sciences, USA 103:
1047–1051. https://doi.org/10.1073/pnas.0602712103
May RM (1988) How many species are there on Earth? Science 241: 1441–1449. https://doi.
org/10.1126/science.241.4872.1441
Morales NE, Zanuncio JC, Pretissoli D, Fabres AS (2000) Fluctuación poblacional de Scolyti-
dae (Coleoptera) en zonas reforestadas con Eucalyptus grandis (Myrtaceae) en Minas Ge-
raes, Brasil. Revista de Biología Tropical 48: 101–107.
Novotny V, Miller SE, Hulcr J, Drew RA, Basset Y, Janda M, Setli GP, Darrow K, Stewart
AJA, Auga J, Isua B, Molem K, Manumbor M, Tamtiai E, Mogia M, Weiblen G (2007)
Low beta diversity of herbivorous insects in tropical forests. Nature 448: 692–697. https://
doi.org/10.1038/nature06021
Ødegaard F (2000) How many species of arthropods? Erwins estimate revised. Biological
Journal of the Linnean Society 71: 583–597. https://doi.org/10.1111/j.1095-8312.2000.
tb01279.x
Oliver JB, Mannion CM (2001) Ambrosia beetle (Coleoptera: Scolytidae) species attacking
chestnut and captured in ethanol-baited traps in Middle Tennessee. Environmental Ento-
mology 30: 909–918. https://doi.org/10.1603/0046-225X-30.5.909
Peltonen M, Heliövaara K, Väisänen R, Keronen J (1998) Bark beetle diversity at dierent spa-
tial scales. Ecography 21: 510–517. https://doi.org/10.1111/j.1600-0587.1998.tb00442.x
Petrov AV, Flechtmann CAH (2013) New data on ambrosia beetles of the genus Sampsonius
Eggers, 1935 with descriptions of three new species from South America (Coleoptera:
Curculionidae: Scolytinae). Koleopterologische Rundschau 83: 173–184.
Petrov AV, Mandelshtam MY (2018) Description of a new species of Cnestus Sampson, 1911,
and notes on other species from South America (Coleoptera: Curculionidae: Scolytinae).
Koleopterologische Rundschau 88: 269–274.
Pitman NCA, Terborgh JW, Silman MR, Núñez P, Neill VDA, Cerón CE, Palacios WA, Aules-
tia M (2001). Dominance and distribution of tree species in upper Amazonian terra rme
forests. Ecology 82: 2101–2117. https://doi.org/10.1890/0012-9658(2001)082[2101:DA
DOTS]2.0.CO;2
Rice, ME (2015) Terry L. Erwin: she had a black eye and in her arm she held a skunk. American
Entomologist 61: 9–15. https://doi.org/10.1093/ae/tmv002
Simon U, Grossner M, Linsenmair KE (2003) Distribution of ants and bark-beetles in crowns
of tropical oaks. In: Basset Y, Novotny V, Miller SE, Kicthing RL (Eds) Arthropods of
Tropical Forests. Cambridge University Press, Cambridge, 59–68.
Sandoval Rodríguez C, Cognato AI, Righi CA (2017) Bark and ambrosia beetle (Curculioni-
dae: Scolytinae) diversity found in agricultural and fragmented forests in Piracicaba-SP,
Brazil. Environmental Entomology 46: 1254–1263. https://doi.org/10.1093/ee/nvx160
Sanguansub S, Buranapanichpan S, Beaver RA, Saowaphak T, Tanaka N, Kamata N (2020)
Inuence of seasonality and climate on captures of wood-boring Coleoptera (Bostrichidae
Scolytine Amazonian canopy diversity 813
and Curculionidae (Scolytinae and Platypodinae)) using ethanol-baited traps in a seasonal
tropical forest of northern ailand. Journal of Forest Research. https://doi.org/10.1080/
13416979.2020.1786897
Smith, SM, Cognato AI (2010) A Revision of Camptocerus Dejean (Coleoptera: Curculionidae:
Scolytinae). Insecta Mundi 148: 1–88.
Smith SM, Petrov AV, Cognato AI (2017) Beetles (Coleoptera) of Peru: A survey of the
Families. Curculionidae: Scolytinae. e Coleopterists Bulletin 71: 77–94. https://doi.
org/10.1649/0010-065X-71.1.77
Southwood TRE (1961) e Number of Species of Insects Associated with Various Trees. e
Journal of Animal Ecology 30: 1–8. https://doi.org/10.2307/2109
unes KH (1998) Bark and ambrosia beetles (Coleoptera: Curculionidae, Scolytinae and Plat-
ypodinae) in a neotropical rain forest. Comparing occurrence and distribution between
dierent forest habitats within a continuous reserve in Costa Rica. PhD esis, University
of Bergen, Bergen.
Wood SL (2007) Bark and Ambrosia Beetles (Coleoptera: Scolytidae) of South America: a
taxonomic monograph. Monte Bean Life Sciences Museum, Brigham Young University,
Provo, 90 pp. [+ 230 plates]
... The diversity of Neotropical scolytine beetles is largely undescribed. Estimates of the Ecuadorian and Peruvian faunas suggest that the fauna is ~3-4 times greater than currently known Dole et al. 2021) and recent taxonomic reviews have revealed several new genera and new species (e.g. Dole and Cognato 2007;Petrov and Mandelshtam 2009;Smith and Cognato 2010;Petrov and Mandelshtam 2010;Petrov 2014;Smith 2017;Cognato 2018;Petrov and Mandelshtam 2018;Bright 2019;Atkinson 2020;Jordal and Smith 2020;Pérez Silva et al. 2020). ...
... In the last major reviews of the Central and South American xyleborine faunas, ~175 species have been recorded and more are likely to be discovered (Wood 1982(Wood , 2007Smith et al. 2017). Indeed, the Amazonian canopy is a source of untapped diversity which may yield an additional 40-80% as compared to the currently known fauna (Dole et al. 2021). Diversification into different habitats and the highly inbred nature of xyleborines may explain the radiation of endemic genera and species that occurred after the colonization of the Americas in the past 15 million years (Cognato et al. 2011;Jordal and Cognato 2012;Gohli et al. 2016). ...
Article
Full-text available
The Neotropical xyleborine ambrosia beetle genus Coptoborus Hopkins is reviewed. The following 40 Coptoborus species are described: C. amplissimus sp. nov. (Peru), C. asperatus sp. nov. (Ecuador), C. barbicauda sp. nov. (French Guiana), C. bettysmithae sp. nov. (Ecuador), C. brevicauda sp. nov. (Ecuador), C. brigman sp. nov. (Ecuador), C. busoror sp. nov. (Ecuador), C. capillisoror sp. nov. (Brazil), C. chica sp. nov. (Suriname), C. crassisororcula sp. nov. (Peru), C. doliolum sp. nov. (Ecuador), C. erwini sp. nov. (Ecuador), C. furiosa sp. nov. (Ecuador), C. galacatosae sp. nov. (Ecuador), C. hansen sp. nov. (Brazil), C. incomptus sp. nov. (Peru), C. janeway sp. nov. (Peru), C. katniss sp. nov. (Ecuador), C. leeloo sp. nov. (Ecuador), C. leia sp. nov. (Ecuador, Suriname), C. leporinus sp. nov. (Peru), C. martinezae sp. nov. (Ecuador), C. murinus sp. nov. (Ecuador), C. newt sp. nov. (Peru), C. osbornae sp. nov. (Ecuador), C. panosus sp. nov. (French Guiana), C. papillicauda sp. nov. (Suriname), C. pilisoror sp. nov. (Ecuador), C. ripley sp. nov. (Ecuador), C. sagitticauda sp. nov. (Guyana), C. sarahconnor sp. nov. (Brazil), C. scully sp. nov. (Ecuador), C. sicula sp. nov. (Ecuador), C. sororcula sp. nov. (Peru), C. starbuck sp. nov. (Ecuador), C. trinity sp. nov. (Brazil), C. uhura sp. nov. (Peru), C. vasquez sp. nov. (Panama), C. vrataski sp. nov. (Brazil), and C. yar sp. nov. (Ecuador). Seventeen new combinations are given: Coptoborus amazonicus (Petrov, 2020) comb. nov., C. atlanticus (Bright & Torres, 2006) comb. nov., C. bellus Bright & Torres, 2006 comb. nov., C. coartatus (Sampson, 1921) comb. nov., C. crinitulus (Wood, 1974) comb. nov., C. exilis (Schedl, 1934) comb. nov., C. incultus (Wood, 1975) comb. nov., C. magnus (Petrov, 2020) comb. nov., C. micarius (Wood, 1974) comb. nov., C. obtusicornis (Schedl, 1976) comb. nov., C. paurus (Wood, 2007) comb. nov., C. pristis (Wood, 1974) comb. nov., C. pseudotenuis (Schedl, 1936) comb. nov., C. puertoricensis (Bright & Torres, 2006) comb. nov., C. ricini (Eggers, 1932) comb. nov., C. semicostatus (Schedl, 1948) comb. nov., C. tristiculus (Wood, 1975) comb. nov., and C. villosulus (Blandford, 1898) comb. nov. Two new synonyms are proposed: Coptoborus Hopkins, 1915 (= Theoborus Hopkins, 1915 syn. nov.) and Coptoborus villosulus (Blandford, 1898) (= Theoborus theobromae Hopkins, 1915 syn. nov.). Xyleborus neosphenos Schedl, 1976 comb. res. is removed from Coptoborus. The revised genus now contains 77 species and a key to their identification is provided.
... The diversity of Neotropical scolytine beetles is largely undescribed. Estimates of the Ecuadorian and Peruvian faunas suggest that the fauna is ~3-4 times greater than currently known Dole et al. 2021) and recent taxonomic reviews have revealed several new genera and new species (e.g. Dole and Cognato 2007;Petrov and Mandelshtam 2009;Smith and Cognato 2010;Petrov and Mandelshtam 2010;Petrov 2014;Smith 2017;Cognato 2018;Petrov and Mandelshtam 2018;Bright 2019;Atkinson 2020;Jordal and Smith 2020;Pérez Silva et al. 2020). ...
... In the last major reviews of the Central and South American xyleborine faunas, ~175 species have been recorded and more are likely to be discovered (Wood 1982(Wood , 2007Smith et al. 2017). Indeed, the Amazonian canopy is a source of untapped diversity which may yield an additional 40-80% as compared to the currently known fauna (Dole et al. 2021). Diversification into different habitats and the highly inbred nature of xyleborines may explain the radiation of endemic genera and species that occurred after the colonization of the Americas in the past 15 million years (Cognato et al. 2011;Jordal and Cognato 2012;Gohli et al. 2016). ...
Article
Full-text available
The Neotropical xyleborine ambrosia beetle genus Coptoborus Hopkins is reviewed. The following 40 Coptoborus species are described: C. amplissimus sp. nov. (Peru), C. asperatus sp. nov. (Ecuador), C. barbicauda sp. nov. (French Guiana), C. bettysmithae sp. nov. (Ecuador), C. brevicauda sp. nov. (Ecuador), C. brigman sp. nov. (Ecuador), C. busoror sp. nov. (Ecuador), C. capillisoror sp. nov. (Brazil), C. chica sp. nov. (Suriname), C. crassisororcula sp. nov. (Peru), C. doliolum sp. nov. (Ecuador), C. erwini sp. nov. (Ecuador), C. furiosa sp. nov. (Ecuador), C. galacatosae sp. nov. (Ecuador), C. hansen sp. nov. (Brazil), C. incomptus sp. nov. (Peru), C. janeway sp. nov. (Peru), C. katniss sp. nov. (Ecuador), C. leeloo sp. nov. (Ecuador), C. leia sp. nov. (Ecuador, Suriname), C. leporinus sp. nov. (Peru), C. martinezae sp. nov. (Ecuador), C. murinus sp. nov. (Ecuador), C. newt sp. nov. (Peru), C. osbornae sp. nov. (Ecuador), C. panosus sp. nov. (French Guiana), C. papillicauda sp. nov. (Suriname), C. pilisoror sp. nov. (Ecuador), C. ripley sp. nov. (Ecuador), C. sagitticauda sp. nov. (Guyana), C. sarahconnor sp. nov. (Brazil), C. scully sp. nov. (Ecuador), C. sicula sp. nov. (Ecuador), C. sororcula sp. nov. (Peru), C. starbuck sp. nov. (Ecuador), C. trinity sp. nov. (Brazil), C. uhura sp. nov. (Peru), C. vasquez sp. nov. (Panama), C. vrataski sp. nov. (Brazil), and C. yar sp. nov. (Ecuador). Seventeen new combinations are given: Coptoborus amazonicus (Petrov, 2020) comb. nov. , C. atlanticus (Bright & Torres, 2006) comb. nov. , C. bellus Bright & Torres, 2006 comb. nov. , C. coartatus (Sampson, 1921) comb. nov. , C. crinitulus (Wood, 1974) comb. nov. , C. exilis (Schedl, 1934) comb. nov. , C. incultus (Wood, 1975) comb. nov. , C. magnus (Petrov, 2020) comb. nov. , C. micarius (Wood, 1974) comb. nov. , C. obtusicornis (Schedl, 1976) comb. nov. , C. paurus (Wood, 2007) comb. nov. , C. pristis (Wood, 1974) comb. nov. , C. pseudotenuis (Schedl, 1936) comb. nov. , C. puertoricensis (Bright & Torres, 2006) comb. nov. , C. ricini (Eggers, 1932) comb. nov. , C. semicostatus (Schedl, 1948) comb. nov. , C. tristiculus (Wood, 1975) comb. nov. , and C. villosulus (Blandford, 1898) comb. nov. Two new synonyms are proposed: Coptoborus Hopkins, 1915 (= Theoborus Hopkins, 1915 syn. nov. ) and Coptoborus villosulus (Blandford, 1898) (= Theoborus theobromae Hopkins, 1915 syn. nov. ). Xyleborus neosphenos Schedl, 1976 comb. res. is removed from Coptoborus . The revised genus now contains 77 species and a key to their identification is provided.
... Species and generic diversity of African and South American ambrosia beetles is under-described and would benefit from increased sampling and taxonomic study (Wood 2007, Cognato et al. 2020, Dole et al. 2021, Jordal 2021a. Collection of more Xenoxylebora throughout its known geographic range for the extraction of additional molecular data would likely reveal additional species, lend greater credibility to the biogeographical conclusions, and help to better define proposed species limits within the genus. ...
Article
Plant-associated arthropods have been shown to cross large oceanic distances on floating plant material and to establish themselves on distant landmasses. Xyleborini (Coleoptera: Curculionidae: Scolytinae) ambrosia beetles occur in forests worldwide and are likely capable of long range dispersal. In less than 20 million years, this group dispersed from Asia to tropical regions of Africa and South America. The phylogeny, taxonomy, and biogeography of one Xyleborus species group which occurs on both continents are reviewed for this study. Based on a well-resolved molecular phylogeny resulting from parsimony, likelihood, and Bayesian analyses of four gene loci, we describe a new monophyletic genus, Xenoxylebora Osborn, Smith & Cognato, gen. nov., for this bicontinental Xyleborus species group with seven Afrotropical and six Neotropical species. Six new species are described: Xenoxylebora pilosa Osborn, Smith & Cognato, sp. nov. from Africa, and Xenoxylebora addenda Osborn, Smith & Cognato, sp. nov., Xenoxylebora calculosa Osborn, Smith & Cognato, sp. nov., Xenoxylebora hystricosa Osborn, Smith & Cognato, sp. nov., Xenoxylebora serrata Osborn, Smith & Cognato, sp. nov., and Xenoxylebora sulcata Osborn, Smith & Cognato, sp. nov., from South America. Seven new combinations from Xyleborus are proposed: Xenoxylebora caudata (Schedl 1957) comb. nov., Xenoxylebora collarti (Eggers 1932) comb. nov., Xenoxylebora perdiligens (Schedl 1937) comb. nov., Xenoxylebora sphenos (Sampson 1912) comb. nov., Xenoxylebora subcrenulata (Eggers 1932) comb. nov., and Xenoxylebora syzygii (Nunberg 1959) comb. nov. from Africa, and Xenoxylebora neosphenos (Schedl 1976) comb. nov. from South America. One new synonym is proposed: Xenoxylebora sphenos (Sampson 1912) = Xyleborus tenellusSchedl 1957 syn. nov. Descriptions, diagnoses, images, and a key to the identification of all 13 species are provided. The sequence of colonization between Africa and South America is uncertain for Xenoxylebora. Prevailing ocean currents and predominant locality patterns observed for other organisms suggest an African Xenoxylebora origin. However, the phylogeny, biogeographical analyses, and a calibrated divergence time suggest a possible South American origin for African Xenoxylebora (2.3 Ma, 95% HDP 4.5–0.6 Ma), which is supported by the occurrence of ocean counter currents between the continents and evidence of dispersal from South America to Africa among some plant and arthropod taxa.
Article
Full-text available
Insects in the tropics usually have continuous generations throughout the year. We reanalyzed published data of wood-boring beetles, belonging to three taxonomic groups (Bostrichidae; Curculionidae: Scolytinae, Platypodinae), that were captured by ethanol-baited traps continuously set for three years and collected every two weeks in the lowland montane forest in northern Thailand. Because trap captures seemed to have 1-yr cycle, we hypothesized that 1-yr cycle of climate had caused 1-yr cycle in the trap captures. To test this hypothesis, cycles of both total trap captures (TTC) and of each species, synchrony in time-series trap captures, and causality of temperature and rainfall to the TTC were determined. Eighty-nine species were captured over the three years. Among 55 species (>2 individuals), 30 species showed the greatest peak of spectral density at 1-yr, but only three were significant. Some species had (a) cycle(s) shorter than one year. However, 20 species making up 69.7% of TTC and 38 species making up 91.1% of TTC showed significant synchrony with TTC diagnosed by the Phillips-Ouliaris cointegration test and Pearson’s correlation function, respectively. Temperature, rainfall, and season (solar elevation angle) showed significant causalities, the effect of season being the strongest. Both temperature and rainfall positively influenced TTC with lags. These results indicate that seasonality in temperature and rainfall caused a 1-yr cycle in flying beetles of a majority of the more abundant species, and synchrony among species, which resulted in the 1-yr cycle of TTC. The revolution and tilt of the earth was a likely driving force.
Article
Full-text available
This study investigated the beetle assemblages, using flight intercept traps set up at different levels (ground, 6 m and 12 m) of an aluminium-alloy tower in a lowland dipterocarp forest in Sabah. A total of 215 morphospecies from 48 families were recorded from 12 samplings between March and September, 2000. Staphylinidae and Scarabaeidae (mainly dung beetles) were the most prominent families, sampled mainly from the ground level. Species richness and abundance of beetles were significantly lower in both 6-m and 12-m levels compared to the ground level. Sampling with mist-blowing from previous study was compared, and the study has shown that the sampling technique is vital in determining prominent beetle groups to be sampled. The high number of beetle singletons sampled in lowland rainforest suggested that beetles are generally resembling non-interactive communities, which can be regarded as non-equilibrium communities.
Article
Full-text available
Land use changes and forest fragmentation result in biodiversity loss and displacement, with insects among the most affected groups. Among these, bark beetles (Curculionidae: Scolytinae) occupy a prominent position due to their close ties to food resources, i.e., trees, and importance as primary decomposers in forest ecosystems. Therefore, our study aimed to document scolytine biodiversity associated with landscape components that vary based on their physical or botanical composition. Bark beetle diversity was sampled monthly for 12 mo in an Atlantic forest remnant and five adjacent vegetation plots (mixed Agroforestry System-AFS, of native trees and fruit species; AFS of rubber trees and coffee plants; coffee monoculture; rubber monoculture; and pasture). In total, 1,833 individuals were sampled from 38 species of which 24 (63%) were detected in very low abundance. The remaining 14 species were more abundant and widespread almost in all areas. Hypothenemus hampei (Westwood), Premnobius cavipennis (Eichhoff), Hypothenemus sp1., and Xyleborus volvulus (Fabricius) were the most abundant. The greatest abundance and richness of bark beetles were found in the dry and cold season. The varied microclimatic conditions of the vegetation plots greatly affected the diversity of the Scolytinae. Solar radiation presented a significant negative effect on abundance in almost all the studied areas. The greatest scolytine diversity was found in anthropic areas with tree canopy structure. Open areas (pasture and coffee monocrop) had a lower species diversity. Similarly, a lower abundance and species richness were found for the Atlantic forest remnant.
Article
Full-text available
The bark and ambrosia beetle fauna (Scolytinae) of Peru is reviewed. Examination of ∼8,000 museum and recently collected specimens and a literature review yielded 106 new country records among 248 species distributed among 56 genera and 15 tribes. Our findings for Peru increase the reported species diversity by ∼75%. Despite this thorough review, at least a hundred more Peruvian species remain to be identified or described. The geographic ranges of some species were discovered to extend more than 1,500 km from Central America or the Guyana Shield to southern Peru. It is unknown if these populations are disjunct or if they represent cryptic species. Our results suggest that only 25% of the South American scolytine fauna is known. A new synonymy of Gymnochilus glaber (Schedl, 1951) = Scolytodes schoenmanni Wood, 2007 is proposed.
Article
The genus Scolytodes Ferrari is a highly diverse group of Neotropical bark beetles. Recent collecting by hand and canopy fogging in Ecuador produced many new records. Overlap in species composition between samples from the canopy and the ground was very low, and canopy fogging revealed the highest proportion of undescribed species. Altogether we report records for 55 species of Scolytodes from Ecuador, including 40 species new to science: Scolytodes pseudoatratus Jordal and Smith, sp. nov., Scolytodes latipes Jordal and Smith, sp. nov., Scolytodes sloanae Jordal and Smith, sp. nov., Scolytodes samamae Jordal and Smith, sp. nov., Scolytodes otongae Jordal and Smith, sp. nov., Scolytodes chaplini Jordal and Smith, sp. nov., Scolytodes projectus Jordal and Smith, sp. nov., Scolytodes lubricus Jordal and Smith, sp. nov., Scolytodes inordinatus Jordal and Smith, sp. nov., Scolytodes cancellatus Jordal and Smith, sp. nov., Scolytodes jubatus Jordal and Smith, sp. nov., Scolytodes abbreviatus Jordal and Smith, sp. nov., Scolytodes stramineus Jordal and Smith, sp. nov., Scolytodes teres Jordal and Smith, sp. nov., Scolytodes animus Jordal and Smith, sp. nov., Scolytodes pseudoanimus Jordal and Smith, sp. nov., Scolytodes bombycinus Jordal and Smith, sp. nov., Scolytodes bisetosus Jordal and Smith, sp. nov., Scolytodes horridus Jordal and Smith, sp. nov., Scolytodes virgatus Jordal and Smith, sp. nov., Scolytodes criniger Jordal and Smith, sp. nov., Scolytodes pseudocrassus Jordal and Smith, sp. nov., Scolytodes semicrassus Jordal and Smith, sp. nov., Scolytodes pseudolepidus Jordal and Smith, sp. nov., Scolytodes semilepidus Jordal and Smith, sp. nov., Scolytodes fortis Jordal and Smith, sp. nov., Scolytodes peniculus Jordal and Smith, sp. nov., Scolytodes tristis Jordal and Smith, sp. nov., Scolytodes chrysifrons Jordal and Smith, sp. nov., Scolytodes amictus Jordal and Smith, sp. nov., Scolytodes cnesinoides Jordal and Smith, sp. nov., Scolytodes maestus Jordal and Smith, sp. nov., Scolytodes vietus Jordal and Smith, sp. nov., Scolytodes echinus Jordal and Smith, sp. nov., Scolytodes rufifrons Jordal and Smith, sp. nov., Scolytodes arcuatus Jordal and Smith, sp. nov., Scolytodes validus Jordal and Smith, sp. nov., Scolytodes sparsus Jordal and Smith, sp. nov., Scolytodes lapillus Jordal and Smith, sp. nov., Scolytodes coronatus Jordal and Smith, sp. nov. We also provide the first description of the female and a new country record for Scolytodes grandis (Schedl, 1962) (=Scolytodes glaberrimus Wood, 1972 syn. nov.) and a redescription and new country record for Scolytodes pilifrons (Schedl, 1962). The total number of valid species is now 287. Additional new country records were established for Scolytodes acuminatus Wood, 1969, Scolytodes comosus Jordal and Kirkendall, 2019, Scolytodes costabilis Wood, 1974, Scolytodes glabrescens Wood, 1972, Scolytodes impressus Wood, 1969, Scolytodes nitidus (Eggers, 1928), Scolytodes striatus (Eggers, 1934), Scolytodes tucumani Wood, 2007, and from another Hexacolini genus, Pycnarthrum fulgidum Wood, 1977. The first molecular phylogeny for Scolytodes is provided and used primarily to guide the inference of species validity. Molecular data from COI, 28S and EF-1α revealed substantial genetic divergence between morphologically very similar but diagnosable species.
Article
The Scolytinae is highly diversified in tropical forests, but richness and abundance patterns within most Ecuadorian forest habitat types are not yet characterized. In this study, we assessed patterns of variation in Scolytinae richness, abundance, and species composition in a primary and a secondary natural forest, and a commercial balsa plantation in Ecuador. We conducted a 1-yr survey of Scolytinae communities with baited traps and measured associated environmental variables. In total, 18,169 Scolytinae individuals were captured and comprised 85 species, 16 genera, and six tribes. In the natural forests, main indicator species were Xylosandrus morigerus, Xyleborus affinis, Xyleborus sp.02, and Corthylus sp.01, whereas all species of Hypothenemus were indicator species in the balsa plantation. The exotic Premnobius cavipennis (Ipini), Xylosandrus compactus, and Xylosandrus morigerus were indicator species for the natural forests. We provide evidence that commercial balsa plantations provide abundant favorable resources for native and exotic scolytines in Ecuador, and that scolytine communities in natural forest and in plantations are more likely to differ in their species composition than in their cumulated species richness. In all habitats, species composition, abundance, and species richness showed temporal patterns of variation that coincided with seasonal variations in climatic conditions, with highest records during the coldest and driest months in the primary forest and the balsa plantation. We provide new knowledge on the native Ecuadorian scolytine fauna and a foundation for the monitoring for potential scolytine pest species of natural and planted tropical forest ecosystems.
Chapter
We report the vertical profile of the species assemblage of ambrosia beetles in a primary forest stand at Pasoh Forest Reserve (Pasoh FR). Ambrosia beetles (xylomycetophagous species of the families Scolytidae and Platypodidae) live in wood, feeding on symbiotic fungi growing on the walls of their galleries. In order to clarify the vertical structure of the assemblage in a tropical rain forest, we used collision traps with ethanol as an attractant set on canopy towers in the forest. In total, 42 species of ambrosia beetles were captured in the ethanol traps placed serially from 1 m to 32 m above the ground. They showed a bi-modal pattern of species distribution in the median height of collection, suggesting that the species are largely divided into canopy species and understorey species. It seems likely that about three quarters of the species are canopy species, probably flying in the main canopy and somewhat shaded subcanopy layers, and most others are understorey species, foraging just above the forest floor. Host taxon selection was not differentiated between the canopy species and the understorey species. However, the canopy species were rather specific to branches of a certain size for each species while the understorey species were mostly generalists in host size selection. Ambrosia beetles are expected to promote early decomposition of wood materials through boring galleries into the wood and infecting them with wooddecaying fungi. Our results suggest that they are rich in species in the forest canopy, where they play an important role in early decomposition and rapid breakdown of standing branches, while some others are confined to the understorey or forest floor, attacking the fallen branches and bigger limbs of trees as well as seedlings.