Beetle Guilds Research Articles

Multifactorial structuring in a local guild of coprophilic scarab beetles from theMexicantransition zone: Analyses of ecological hypotheses

AbstractDifferent hypotheses have been proposed to explain the environmental gradients‐biotic structuring relationship. Nevertheless, several inconsistencies have arisen when only one hypothesis is chosen to explain the biological diversity patterns. Our aim is to test a multiple hypotheses approach to explain the structure of a coprophilic scarab local guild.Coprophilic Scarabaeoidea beetles were sampled for 33 sites along the study region (Los Chimalapas, Oaxaca, Mexico). Several environmental variables were used to test four hypotheses for geographic gradients: Productivity, ambient energy, habitat heterogeneity and temporal heterogeneity. Generalised linear mixed models were used to test the relationship of the hypotheses on the abundance, species richness and Shannon‐Wiener diversity of the local guild. Moreover, canonical correspondence analysis was performed to analyse the effects on species composition.Abundance was negatively affected by the simultaneous effect between two habitat heterogeneity factors, while both species richness (positive effect) and Shannon‐Wiener diversity (negative effect) were mainly related to productivity, and species composition was mainly explained by habitat heterogeneity.We conclude that multiple hypotheses, both based on species‐energy and heterogeneity, need to be considered to explain biotic setting of communities, ensembles, assemblages, local guilds and other complex biotic systems.

Urban intensity and flower community structure drive monkey beetle assemblage in Cape Town

Background: Urban landscapes present an important opportunity for pollinator conservation, but little is known about the status and distribution of pollinator populations in urban habitats in Africa. This represents a major gap in the development of a global understanding of urban pollinators – particularly from the rapidly urbanising context. This study uses a speciose clade of flower-visiting beetles (Coleoptera: Scarabaeidae: Hopliini) to explore patterns of pollinator distribution in a major metropolitan area in South Africa. Objectives: We investigated community composition across gradients of urban intensity (defined according to the percentage of soil-sealing within 1 km2 of each sampling location) and socio-economic status to determine pollinator responses to these urban landscape effects. Methods: A selection of 142 sites were surveyed twice in the austral spring seasons of 2018 and 2019. Data were collected on habitat structure, flower diversity, and pollinator diversity. Results: The study found that different feeding guilds of monkey beetles favoured different levels of urban intensity and that beetle richness significantly correlated with flower richness. It did not, however, correlate with diversity indicating that abundance is less impacted than the number of species present. Monkey beetles with moderate sensitivity to urban intensity benefitted from the presence of preferred species of flowers. Conclusion: Overall, the findings demonstrate the importance of plant community assemblage in supporting urban monkey beetles. We recommend landscaping with preferred flower species in urban parks to support urban pollinators.

Partitioning resources through the seasons: abundance and phenology of carrion beetles (Silphidae) in southeastern Ontario, Canada

The coexistence of ecologically similar species is thought to require resource partitioning to minimize competition. Phenological, seasonal differences in activity may provide an important axis for resource partitioning. Here, we test for evidence of seasonal differences in activity within a diverse guild of carrion beetles (Silphidae) in a habitat preserve on the Frontenac Arch, southeastern Ontario, Canada, using a large-scale survey during their active seasons (April to October). We then used generalized additive models to test for differences in seasonal abundance among eight co-occurring carrion beetle species, including five species of burying beetles (Nicrophorinae: Nicrophorus Fabricius, 1775) and three species from the Silphinae subfamily. Consistent with previous work, all species showed seasonal variation in abundance, with peak abundance of most species occurring between June and August. All but one species (Nicrophorus sayi Laporte, 1840) showed positive relationships between abundance and temperature. We find evidence consistent with seasonal partitioning of resources among Nicrophorus habitat generalists that could potentially reduce competition for limited carrion resources. In contrast, we find little evidence for seasonal differences in abundance among Nicrophorus habitat specialists, which instead may partition resources spatially. Overall, our results provide evidence consistent with an important role for seasonal resource partitioning among carrion beetle species that show higher levels of spatial (habitat) overlap within a temperate beetle guild.

Body size variation in a guild of carrion beetles

Body size is a key biological trait, influencing the biomechanics, physiology, behaviour, and ecology of species. Describing variation in body size within and among co-occurring species within an ecological guild can provide important context for understanding the ecology of species and the structure of ecological communities. Here, we focus on a guild of carrion beetles (Coleoptera: Silphidae) co-occurring in southeastern Ontario, Canada. We examine how body size varies (i) among species, (ii) within species, including among sexes, and (iii) across the active season, contrasting estimates of size based on mass with those based on morphological structure (elytron length). We find that body size varies significantly both within and among species. Five focal species show evidence for sexual dimorphism in size. All focal species show significant seasonal variation in size, but these patterns differ across species, and depend on our estimates of size. Overall, the observed variation in body size is most consistent with widespread environmental constraints on size and (or) diverse selective pressures favouring different sizes within and among species. We discuss possible selective pressures acting on size within and among species; however, the causes and consequences of the variation in body size that we describe remain to be discovered.

Forest decline differentially affects trophic guilds of canopy-dwelling beetles

Decline can affect the structure, resources, and microclimates of the forest canopy, and potentially have cascading effects on canopy-dwelling species. Our survey shows that an oak decline can promote saproxylic beetles, especially xylophagous ones, and generalist phyllophagous weevils. However, it negatively affects specialist leaf-eating species and has no effect on seed-eating weevils. Decline in a context of climate change is expected to induce considerable changes in forest structure, potentially affecting habitat opportunities and trophic resources for numerous species. Nonetheless, the consequences of decline in forest biodiversity have rarely been studied. We aimed to characterize the impact of oak decline on different guilds of canopy-dwelling beetles. Beetles were sampled for three consecutive years in oak stands exhibiting different levels of decline. Several guilds were considered: (i) Buprestidae, (ii) other saproxylic beetles split into wood-boring species and non-wood-boring species, (iii) seed-eating weevils, and (iv) specialist and generalist leaf-eating weevils. Overall, decline had positive effects on the abundance and biomass of beetles, though contrasting variations were observed at the species or guild levels. Wood-boring species, especially the main oak-associated buprestids, and other saproxylic species benefitted from decline conditions. However, at odds with the insect performance hypothesis, decline had a positive effect on generalist leaf-eating species, a negative effect on specialist leaf-eating species, and a null effect on seed-eating species. The increase in species richness for saproxylic and leaf-eating beetle communities suggests that decline might promote forest biodiversity. Our results call for further studies to thoroughly assess the functional outcomes of forest decline and to suggest management strategies for conservation biologists.

The scale of saproxylic beetles response to landscape structure depends on their habitat stability

Forest management and disturbances cause habitat fragmentation for saproxylic species living on old-growth attributes. The degree of habitat spatiotemporal continuity required by these species is a key question for designing biodiversity-friendly forestry, and it strongly depends on species’ dispersal. The “stability–dispersal” model predicts that species using stable habitats should have lower dispersal abilities than species associated with ephemeral habitat and thus respond to habitat availability at smaller scales. We aimed at testing the stability–dispersal model by comparing the spatial scales at which saproxylic beetle guilds using substrates with contrasted stability (from stable to ephemeral: cavicolous, fungicolous, saproxylophagous and xylophagous guilds) are affected by landscape structure (i.e. habitat amount and aggregation). We sampled saproxylic beetles using a spatially nested design (plots within landscape windows). We quantified habitat availability (tree cavities, polypores and deadwood) in 1-ha plots, 26-ha buffers around plots and 506-ha windows, and analyzed their effect on the abundance and diversity of associated guilds. The habitat amount within plots and buffers positively affected the abundance of the cavicolous and the fungicolous guilds whereas saproxylophagous and xylophagous did not respond at these scales. The habitat aggregation within windows only positively affected the saproxylophagous species richness within plots and also on the similarity in species composition among plots. Beetle guilds specialized on more stable habitat were affected by landscape structure at smaller spatial scales, which corroborated the stability–dispersal model. In managed forests, the spatial grain of conservation efforts should therefore be adapted to the target habitat lifetime.

Impact ofBeauveria bassiana(Ascomycota: Hypocreales) on the Small Southern Pine Engraver (Coleoptera: Scolytidae) in a Loblolly Pine Bolt Assay1

Abstract The small southern pine engraver, Ips avulsus Eichhoff (Coleoptera: Scolytidae), is one member of a guild of southern pine bark beetles that causes millions of dollars of losses to southern U.S. pine forests annually. Our objective was to determine the impact of a commercial preparation of the entomopathogenic fungus Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Ascomycota: Hypocreales) in protecting pine host plant tissue from colonization and damage by I. avulsus and on the B. bassiana–induced mortality of I. avulsus adults during the first 2 wk of host attack. The field trials were conducted in the Kisatchie National Forest (Rapides Parish, LA) using a small-bolt technique. Results showed that the I. avulsus adults successfully colonized both the B. bassiana–treated bolts and the control bolts within the first week of field exposure. Although the formulation did not protect bolts from attack, it caused significantly higher mortality of I. avulsus adults in B. bassiana–treated bolts than in ...

Trap height considerations for detecting two economically important forest beetle guilds in southeastern US forests

Wood-infesting beetles continue to be introduced into new areas at high rates through global trade. Once established, these species can be difficult or impossible to eradicate and can be extremely damaging to both ecosystems and economies. Efforts to detect newly arrived species before they become widespread represent an important early line of defense against these threats. There is considerable interest in optimizing trapping methods to best detect taxa of greatest concern. The purpose of this paper is to explore the role of trap height in influencing detection rates for two economically important guilds of forest Coleoptera [phloem/wood feeders (Buprestidae, Cerambycidae and some scolytine Curculionidae) and ambrosia beetles (scolytine Curculionidae)]. We examine this question using three datasets from southeastern US forests. In general, we found phloem/wood feeders and ambrosia beetles to exhibit contrasting vertical distribution patterns. Whereas phloem/wood feeders generally became more species-rich and abundant with increasing trap height, the opposite pattern was found for ambrosia beetles. Moreover, all species found to be significantly associated with the highest traps were phloem/wood feeders, whereas all but one of the species significantly associated with the lowest traps were ambrosia beetles. It is clear from these findings that detection efforts targeting both guilds will be most effective when traps are deployed at multiple heights in southeastern US forests.

Temporal Resource Partitioning and Interspecific Correlations in a Warm, Temperate Climate Assemblage of Dung Beetles (Coleoptera: Scarabaeidae)

Guilds of dung dwelling and tunneling dung beetles coexist in local assemblages in warm temperate regions, despite the tendency of dwellers to be inferior competitors. A field experiment on the Black Sea coast of Turkey examined the role of temporal resource partitioning in their coexistence. Standardized dung pads deposited at 4 h intervals through a 24 h period in summer were collected 12, 24, or 48 h later. Adults from 10 tunneling and seven dung dwelling species were collected. The tunnelers contributed a high proportion of both total abundance and biomass. There was a significant effect of dung deposition time and exposure period on mean tunneler abundance. Mean tunneler abundance was nearly seven times higher in dung deposited at 06:00 than at 18:00. The dwellers reduced the potential for competitive interactions with tunnelers by relatively uniform dispersal across the six dung deposition times. The distinctly different dung use patterns by dwellers and tunnelers demonstrated temporal resource partitioning. Interspecific correlation coefficients were also determined because interspecific relationships are at the core of resource partitioning. Total tunneler and dweller abundances were not correlated. Overall, there were strong positive correlations between tunneling species and low correlations between tunneling and dwelling species, and between dwelling species. The five most abundant tunnelers, from two tribes and three genera, were strongly positively correlated. There were substantial size differences among the four most abundant tunnelers that probably facilitate their coexistence.

Diversity distribution of saproxylic beetles in Chilean Mediterranean forests: influence of spatiotemporal heterogeneity and perturbation

Mediterranean ecosystems have been recognized as a priority for biodiversity conservation due to their high levels of species richness and endemism. In South America, these environments are restricted to central Chile and represent a biodiversity hotspot. The study of saproxylic beetles in this area is an unexplored topic, despite the ecological role they play in these ecosystems and their potential usefulness for monitoring the degree of forest conservation. We investigated the diversity distribution of trophic guilds of saproxylic beetles in Chilean Mediterranean forests, to identify the main environmental variables that influence their distribution. We also analyzed seasonal dynamics as a key factor influencing insect communities and the effect of human disturbance on their diversity and composition. We identified characteristic species of perturbation degree as bioindicators for habitat monitoring. A total of 40 window traps were used to survey three Mediterranean forest types in the Rio Clarillo National Reserve and the adjacent non-protected areas. We found that the diversity, abundance and composition of saproxylic beetles varied significantly spatiotemporally among the studied forest types and among perturbation degrees, showing different patterns depending on the trophic guild. Results indicated that conservation decisions should include the preservation of a larger range of different vegetation types and the nearby zones that have suffered low levels of disturbance or fragmentation and where actions promoting the presence of old native trees would have a significant conservation value.

Contributions of the mammal community, habitat structure, and spatial distance to dung beetle community structure

Dung beetles feed and nest in mammal feces, are influenced by habitat quality and have limited dispersal ability. We hypothesized that dung beetle community structure is affected by mammal composition, habitat structure, and spatial distance, and that these predictors vary among the functional groups in communities. Dung beetles and mammals were sampled using pitfall traps and camera traps, respectively, at 15 Atlantic Forest sites between 2005 and 2013. Habitat structure was described using the point-quadrant method. We utilized descriptive ecological values and used variation partitioning to identify predictors of dung beetle community composition both as a whole, and after organizing the community into functional groups. We recorded 43 dung beetle species and 28 mammal species. Mammal and dung beetle species richness were positively correlated. Mammals and habitat explained the majority of the variation among dung beetle communities, and explanatory values varied substantially when using the functional group approach. Our results indicate that mammals are, indeed, important drivers of dung beetle community structure. Individually, or in combination with habitat structure, mammal composition explained 40 % of the total variation in dung beetle data, i.e., the abundance and species composition of dung beetles and mammals covary. However, herbivorous mammals, medium-sized mammals and omnivorous mammals numerically contributed more than did other groups to the explanation of variation in dung beetle guilds. Habitat structure was an important determinant for dung beetle functional group abundance, and spatial distance influenced covariation between dung beetles and mammals. Thus, the integrity and maintenance of ecological processes in the Atlantic Forest may be dependent on these groups, and further fragmentation, habitat loss and defaunation may increase the sensitivity of this already reduced and threatened biome.

Species composition and functional guilds of dung beetles (Insecta: Coleoptera: Scarabaeidae: Scarabaeinae) in different vegetational types in the Brazilian Shield–Chacoan Depression Border

SummaryThe present study was carried out in Chapada dos Guimarães (Brazilian Shield-Chacoan Depression Border), Mato Grosso, Brazil. In this paper we describe the species and composition of dung beetles in different vegetational environments in the Brazilian Shield–Chacoan Depression Border, to associate species present in each habitat to their known distributions, in order to determine whether this region is a biogeographic transition zone. We also update the first checklist of dung beetles from this region published over a century ago. We collected 17,635 individuals of dung beetles belonging to 98 species. Dung beetle fauna responded to the abrupt variation of altitude; in the upland savanna formations we observed species which are predominantly distributed in the Cerrado biogeographic province, whilst the lowland savanna formations were mainly constituted by species which are commonly distributed in the provinces of Chaco or Chaco + Cerrado. Forest formations harbor species which occur frequently in the Amazon sub-region. Due to several overlapped biotic components and also associated with the local endemism records, we regard the region as a biogeographic transition zone for dung beetles.

The importance of heterogeneity revisited from a multiscale and multitaxa approach

The importance of spatial scale for β-diversity has been shown in several studies, but it is unclear how spatial diversity patterns correlate among different organismic groups. We studied spatial diversity organization of plants and several trophic guilds of beetles in beech-dominated forests in two regions of Germany to test whether different trophic guilds are organized independently in space. We applied multiplicative diversity partitioning using a nested hierarchical design of four increasingly broader spatial levels (subplot, plot, forest class, region) and tested for correlations among trophic guilds by using Pearson product moment correlations and Mantel-tests. We observed similar general diversity patterns at different trophic guilds showing a high contribution of β-diversity to total γ-diversity and found β-diversity to be higher at different spatial scales and α-diversity to be lower than expected by random distributions of individuals. Results, however, partly depended on the weighting of rare and abundant species. Beta-diversity in our study was caused mainly by species spatial turnover rather than by nestedness. Correlations of α-diversity between trophic guilds were low whereas correlations of β-diversity above subplot level were high. Importantly, more strongly connected trophic guilds revealed not generally stronger relationships than less strongly connected guilds. Three important implications for conservation can be deduced from our results: (1) heterogeneity of beech forests at different spatial scales should be supported in conservation strategies to enhance biodiversity and related functions; (2) the observed high importance of spatial turnover in relation to nestedness implies a concentration of conservation efforts to a large number of not necessarily the richest sites, and (3) recommendation for particular conservation strategies (e.g. selection of priority sites for conservation at regional scale) based on single indicator taxa or functional guild is difficult because of the varied response of the species in our study.

Species diversity and community structure of rove beetles (Coleoptera: Staphylinidae) attracted to dung of sika deer in coniferous forests of southwest Japan

AbstractInsect communities of mammal dung have been known as excellent model ecosystems for scientific study. Ecological surveys of diversity and seasonal patterns of coprophilous rove beetles in relation to wild mammals have rarely been conducted, although the high potential species diversity and abundance of the rove beetles are known. In order to investigate biodiversity of these beetles, we analyzed species composition, abundance, feeding guild and seasonality of rove beetles that were attracted to sika deer Cervus nippon dung by using dung‐baited pitfall traps for a 1.5‐year study in two plantations (cypress, cedar) and one secondary natural forest (pine) in Fukuoka Prefecture, southwest Japan. Consequently, saprophagous Anotylus sp. (Oxytelinae) was dominant in all forests. Analyses of feeding guild structure showed the number of individuals were dominated by saprophagous beetles, but the number of species were dominated by predatory beetles. Seasonal effects suggested that the species richness and abundance of rove beetles are possibly regulated by scarabaeoid dung beetles. These findings feature one example of a coprophilous rove beetle community.

Effect of dead wood enrichment in the canopy and on the forest floor on beetle guild composition

In managed forests, the abundance and diversity of saproxylic insect species and beetles in particular has been argued to be primarily limited by the amount of dead wood while the importance of other factors for community composition of this functional group has been largely neglected. It has also been argued that management regimes that lead to increasing amounts of dead wood in forests will increase the abundance and diversity of saproxylic species, but experimental evidence for this assumption is rare. We studied the importance of dead wood and a number of abiotic and biotic factors for community composition of saproxylic species in a range of managed forests in Germany for 2years and found that the total amount of dead wood in the forests only played a minor role in explaining the composition of the saproxylic beetle community compared to other factors such as precipitation, temperature, tree species and vertical stratum. We then tested for eight forest plots whether dead wood experimentally exposed in the canopy and forest floor is attractive to saproxylic beetles. We found that a high diversity and abundance of beetles of various habitat and feeding guilds, were attracted to fresh dead wood, many more than in control areas without dead wood manipulation. Thus, in managed forests where abundance and diversity of saproxylic beetles is low, enrichment of dead wood resulted in an immediate increase of species and a change of guild composition particularly in the canopy. Our results suggest that the amount of ground dead wood is by itself not a sufficient measure for the local diversity of saproxylic beetles. We conclude that dead wood enrichment in managed forests is an effective strategy to promote saproxylic beetle diversity. Changes in the functional composition are expected to be large enough to influence ecosystem processes such as decomposition of dead wood or the control of herbivores.

Species ecological preferences predict extinction risk in urban tenebrionid beetle guilds

A number of studies have attempted to investigate which species traits influence species proneness to extinction in vertebrates. By contrast, studies involving insects are scarce, because of difficulties in obtaining complex assessments of species extinction risk and measures of species traits. In this paper, a simple (binary) codification based on literature data and field observations was used to determine the importance of various traits (notably ecological preferences) in determining species vulnerability of the tenebrionid beetles inhabiting urban Rome (Italy). Vulnerability scores were calculated from measures of geographical, habitat and population rarity. Vulnerable species were distributed with similar proportions among different tenebrionid guilds, which suggests that conservation programs in urban ecosystems should be more addressed to the development of species-oriented actions than to the identification of priority ‘habitats’. Species traits accurately predicted species assignment to vulnerability classes, with some traits being particularly important in determining species vulnerability. Species associated with ruins and cellars, and which are typically fairly common in Rome, tend to be moderately or middle vulnerable. The identification of important sites for these species and definition of measures for population management would be useful strategies to preserve them.

The multidimensional space of integral characteristics: Invariance of its structure to various biocenotic assemblages

In the virtual multidimensional space of integral biocenotic characteristics, such as abundance, the sizes of individuals, and the components of species diversity, which are scaled on corresponding coordinate axes, the points that represent samples from various biocenotic assemblages, form similar multi-layered hill-shaped figures. The examples we considered are the pelagic macrofauna of the Bering Sea, the Sea of Okhotsk, the Sea of Japan and the adjacent waters of the Northwestern Pacific Ocean; the phytoplankton, zooplankton, and zoobenthos of Lake Ladoga, the Neva Bay, and the Gulf of Finland in the Baltic Sea; the beetle guild in the rainforest of Borneo Island on the Malay Archipelago; and the bird taxocenes and biotope groups of soil mites in North America, among others. The obvious similarity of the composed diagrams results from the close interrelationships of all the integral characteristics and also from the universality of the structure of links between them, which is tolerant to movements in the real space-time continuum and invariant towards the subject of the studies. The multidimensional domain of the analyzed variables is a set of points that are aggregated along a segment, whose length and orientation relative to the coordinate axes determine the general rules of the biocenotic organization of the living matter.

Species abundance distributions of moth and beetle assemblages in a cool‐temperate deciduous forest

Abstract Species abundance distributions of moth and beetle assemblages, in addition to beetle feeding guilds, were examined using data collected by light traps in a cool‐temperate deciduous forest at Hokkaido, Japan. Four types of species abundance distributions with a continuous shift in shape (broken stick, log‐normal, power function, and dispersal‐limited multinomial) were fitted and compared, and then the deviation of observed data from that expected for the neutral model (dispersal‐limited multinomial distribution) was tested using species evenness and richness. Significantly better fits were obtained for the neutral model than for the other models for all assemblages and all beetle guilds. This result implies that the better fits of the neutral model might be characteristic of transient assemblages having an excess of rare species. The evenness of species abundance distributions for assemblages and guilds, except for moths associated with the understorey and predatory beetles, significantly deviated from that expected by the neutral model. The departure of beetle guilds (detritivores, herbivores, and xylophages) from the neutral model suggests their microhabitat dependence. The neutral model may prove to be a viable null hypothesis for examining the species abundance distributions of insect assemblages. In this study, we found that although stochastic dynamics appeared to have an increasing influence on insect community assembly, there are also complex biological processes still likely to be present. The fits of the neutral model suggest that habitat connectivity and microhabitat diversity are potentially important for conserving moth and beetle diversity in a temperate forest.

Molecular evidence of facultative intraguild predation by Monochamus titillator larvae (Coleoptera: Cerambycidae) on members of the southern pine beetle guild

The southern pine bark beetle guild (SPBG) is arguably the most destructive group of forest insects in the southeastern USA. This guild contains five species of bark beetles (Coleoptera: Curculionidae: Scolytinae): Dendroctonus frontalis, Dendroctonus terebrans, Ips avulsus, Ips calligraphus, and Ips grandicollis. A diverse community of illicit receivers is attracted to pheromones emitted by the SPBG, including the woodborers Monochamus carolinensis and Monochamus titillator (Coleoptera: Cerambycidae). These woodborers have been traditionally classified as resource competitors; however, laboratory assays suggest that larval M. carolinensis may be facultative intraguild predators of SPBG larvae. This study used polymerase chain reaction (PCR)-based molecular gut content analyses to characterize subcortical interactions between M. titillator and members of the SPBG. The half-lives of SPBG DNA were estimated in the laboratory prior to examining these interactions in the field. A total of 271 field-collected M. titillator larvae were analyzed and 26 (9.6%) tested positive for DNA of members of the SPBG. Of these larvae, 25 (96.2%) tested positive for I. grandicollis and one (3.8%) for I. calligraphus. Failure to detect D. terebrans and D. frontalis was likely due to their absence in the field. I. avulsus was present, but primers developed using adult tissues failed to amplify larval tissue. Results from this study support the hypothesis that larval Monochamus spp. are facultative intraguild predators of bark beetle larvae. Additionally, this study demonstrates the capabilities of PCR in elucidating the interactions of cryptic forest insects and provides a tool to better understand mechanisms driving southern pine beetle guild population fluctuations.

Diversity and composition of arboreal beetle assemblages in tropical pasture afforestations: effects of planting schemes and tree species identity

Timber tree plantations are considered for rehabilitating forest biodiversity in the tropics, but knowledge on determinants of faunal diversity patterns in such human-modified forest landscapes is scarce. We quantified the composition of beetle assemblages on three native timber species (Anacardium excelsum, Cedrela odorata and Tabebuia rosea) planted on former pasture to assess effects of tree species identity, tree species diversity, and insecticide treatment on a speciose group of animals in tropical plantations. The beetle assemblage parameters ‘abundance’, ‘species richness’, ‘Chao1 estimated species richness’ and ‘Shannon diversity’ were significantly reduced by insecticide treatment for each tree species. Shannon diversity increased with stand diversification for T. rosea but not for A. excelsum and C. odorata. Species similarity was highest (lowest species turnover) between beetle assemblages on T. rosea, and it was lowest (highest species turnover) for assemblages on insecticide-treated trees of all timber species. Considering trophic guilds, herbivorous beetles dominated on all tree species and in all planting schemes. Herbivores were significantly more dominant on T. rosea and C. odorata than on A. excelsum, suggesting that tree species identity affects beetle guild structure on plantation trees. Insecticide-treated stands harbored less herbivores than untreated stands, but exhibited a high abundance of predator beetle species. Our study revealed that even young pasture-afforestations can host diverse beetle assemblages and thus contribute to biodiversity conservation in the tropics. The magnitude of this contribution, however, may strongly depend on management measures and on the selected tree species.