Beetle Species Research Articles

Evidence for 3-hydroxyhexan-2-one as a shared pheromone component for 12 South American species of cerambycid beetles.

3-Hydroxyhexan-2-one (3-C6-ketol) has emerged as the most conserved pheromone structure within the beetle family Cerambycidae. In this study, we report the sex-specific production of this compound by males of 12 species of South American cerambycid beetles. Males of Chrysoprasis chalybea Redtenbacher and Mallosoma zonatum (Sahlberg) (Tribe Dichophyiini), and Ambonus lippus (Germar), Eurysthea hirta (Kirby), Pantonyssus nigriceps Bates, Stizocera plicicollis (Germar), and Stizocera tristis (Guérin-Méneville) (Elaphidiini) produced 3R-C6-ketol as a single component, whereas males of Neoclytus pusillus (Laporte & Gory) (Clytini), Aglaoschema concolor (Gounelle), Orthostoma abdominale (Gyllenhal) (Compsocerini), Dorcacerus barbatus (Olivier), and Retrachydes thoracicusthoracicus (Olivier) (Trachyderini) produced 3R-C6-ketol, along with lesser amounts of other compounds. In field trials testing 8 known cerambycid pheromone compounds, C. chalybea, E. hirta, and R. t. thoracicus were attracted in significant numbers to traps baited with 3-C6-ketol. A second field experiment provided support for the strategy of using the attraction of cerambycid species to test lures as a method of providing leads to their likely pheromone components. Because both sexes are attracted to these aggregation-sex pheromones, live beetles can be obtained from baited traps to verify they produce the compound(s) to which they were attracted, that is, that the compounds are indeed pheromone components.

Additions to the taxonomy of the genus Ophionea Klug, 1821 (Coleoptera: Carabidae: Lebiinae) and a new species from India

A new ground beetle species Ophionea vvrei sp. nov. is described from South India, with revised key to the species of the genus Ophionea, revised descriptions of O. bhamoensis bhamoensis (Bates, 1892) and O. interstitialis Schmidt-Göbel, 1846, first report of Ophionea ceylonica (Baehr, 1996) from Indian mainland and designation of the lectotype of O. indica (Thunberg, 1784).

Edge history modulates the depth of edge influence: Evidence from ground beetles with different feeding traits

Anthropogenic habitat loss and fragmentation are major concerns to conservationists, since these processes lead to species decline and extinction. Edge effect is one of the most important causes of biodiversity losses in fragmented habitats. The depth of edge influence, the distance over which the edge effect penetrates into the adjacent habitat is a central issue, as it fundamentally determines whether the habitat fragment has any remaining core habitat, which is essential for the survival of habitat specialist species. We reviewed 204 edge studies on ground beetles (Coleoptera: Carabidae) of different feeding habits, in forests, one of the habitats most impacted by humans. Meta-analysing 1814 abundance data of 351 ground beetle species from forest edges and their adjoining interiors, we showed that forest edges had significantly higher abundance of herbivorous, omnivorous, and predatory ground beetles than their interiors. Edge history considerably affected the depth of edge influence which on all trophic groups was similar in natural edges and those maintained by agriculture (≤ 10–20 m), while it was wider (> 300 m) when created by forestry or other anthropogenic activities. Consequently, the minimum area of a forest fragment should be ∼ 330 ha in order to keep half of it as core habitat to preserve forest-interior species.

Why are there so many beetle species?

Why are there so many beetle species?

Unexpected Formation of 11(9→7)-abeo-Steroid Skeleton in Synthetic Studies toward Batrachotoxin.

Batrachotoxin (1) is a potent cardio- and neurotoxic steroid isolated from certain species of frogs, birds, and beetles. We previously disclosed two synthetic routes to 1. During our synthetic studies toward 1, we explored an alternative strategy for efficiently assembling its 6/6/6/5-membered steroidal skeleton (ABCD-ring). Here we report the application of intermolecular Weix and intramolecular pinacol coupling reactions. While Pd/Ni-promoted Weix coupling linked the AB-ring and D-ring fragments, SmI2-mediated pinacol coupling did not cyclize the C-ring. Instead, we discovered that SmI2 promoted a 1,4-addition of the α-alkoxy radical intermediate to produce the unusual 11(9→7)-abeo-steroid skeleton. Thus, this study demonstrates the convergent assembly of the skeleton of the natural product matsutakone in 11 steps from 2-allyl-3-hydroxycyclopent-2-en-1-one.

First Description of the Immature Stages of Philonthus spinipes Sharp, 1874 (Coleoptera: Staphylinidae: Staphylininae) – An Adventive Rove Beetle Species in Europe, with Notes on Its Biology, Ecology and Zoogeography

First Description of the Immature Stages of Philonthus spinipes Sharp, 1874 (Coleoptera: Staphylinidae: Staphylininae) – An Adventive Rove Beetle Species in Europe, with Notes on Its Biology, Ecology and Zoogeography

Cretafrica orapensis: a new genus and species of Mycetoporinae (Coleoptera: Staphylinidae) from lacustrine deposits at Orapa Diamond Mine, Botswana

Abstract A new genus and species of staphylinid beetle, Cretafrica orapensis gen. nov. et sp. nov. is described using a single well-preserved impression fossil from an Upper Cretaceous fossil insect deposit, the Orapa Diamond Mine in Botswana. Cretafrica is placed in the extant subfamily Mycetoporinae based on its general habitus, typical sublimuloid medium-to-large body form, elongated head, visible ridge on ventral side of head under eyes, antennomeres increasing in length and width apically, scutellum with basal carina that is distinctly divided medially, elevated area along suture of the elytra, and presumably large metacoxae, and tapering abdomen. It differs from other Mycetoporinae by its triangular head and elytra with broadly rounded apico-lateral margins. A possible preservation distortion illustrates brush-like or fork-like mouthparts. The fossil insect may have been found in forest litter or fresh and rotting mushrooms at Orapa. It confirms the widespread distribution of mycetoporines with phytophagous or mycophagous lifestyles during the mid-Cretaceous. Moreover, like other described fossil staphylinids, the fossil portrays morphological stasis dating back to the Cretaceous. It further confirms the proposed punctuated equilibrium pattern of evolution.

First Record of Leucopholis lepidophora Blanchard, 1850 (Scarabaeidae; Melolonthinae) from Western Himalayas along with a Checklist of the Genus Leucopholis from India

Melolonthinae is a subfamily of June beetles and contains many species of agronomic importance in India. It holds major genera like Brahmina (Blanchard 1850), Eotrichia (Medvedev 1951), Holotrichia (Hope 1837) and Sophrops (Fairmaire 1887) in India. A survey based on light trap collection was conducted in the terai foot hills of the Western Himalaya in Uttarakhand to check for the presence of the species. During surveys in the years 2021-22 and 2022-23, various chafer beetles were collected to observe the distribution pattern and their hosts. Among these various species, one beetle species is here reported for the first time i.e., Leucopholis lepidophora Blanchard, 1850, from Uttarakhand, India. This also represents their first record for Western Himalaya. Their habitus and male genitalia are provided herein to aid in identification. A preliminary checklist of Indian Leucopholis is also provided.

First molecular identification of Haemonchus contortus (Nematoda: Trichostrongylidae), a blood-sucking gastric nematode of artiodactyles, in the ground beetle Carabus granulatus (Coleoptera: Carabidae).

Among gastrointestinal nematodes, Haemonchus contortus (Rudolphi) Cobb (order Strongylidae; family Trichostrongylidae) is one of pathogenic and economic importance in domestic and wild ruminants, including the European bison, Bison bonasus Linnaeus (order Cetartiodactyla; family Bovidae); a species on the International Union for Conservation of Nature's Red List of Threatened Species. Carabus granulatus Linnaeus (order Coleoptera; family Carabidae) is one of the most prevalent species of ground beetle, inhabiting a wide range of terrestrial ecosystems in Poland. Twenty-six ground beetles of this species inhabiting the Białowieża Primeval Forest in eastern Poland were screened for the presence of DNA of pathogenic gastrointestinal nematodes of ruminants. Extracted DNA was sequenced and compared to reference sequences. In six insects, the presence of H. contortus DNA was detected. The obtained nucleotide sequences were homologous to each other and to the majority of the published DNA sequences of H. contortus isolates. The sequences were also identical to a sequence of H. contortus isolated from European bison in Poland. The study provides the first molecular evidence of the presence of H. contortus DNA in C. granulatus. The finding suggests that ground beetles may play a role in the transmission dynamics of this parasite.

Faunal inventory and illustrated taxonomic keys to aquatic Coleoptera (Arthropoda: Insecta) of the northern Western Ghats of Maharashtra, India

Following several surveys of aquatic Coleoptera during 2013–2018 in northern Western Ghats, India, we hereby provide an illustrated checklist with modified keys to the species of families Dytiscidae, Gyrinidae, Noteridae, and Hydrophilidae. To date, we have collected 69 species of true water beetles, adding new occurrence records for two species to the fauna of the state. Keys are modified from the works of various authors. Distribution records are provided with district specific records for Maharashtra. Keys, species lists, and distribution records are based on our survey results. Species were identified following the works of various authors, and affirmed by dissecting male genitalia. Provided with keys are habitus images, images of male genitalia for 59 species, and digital drawings & scanning electron micrographs of taxonomically important structures wherever necessary. These surveys were conducted to revive the work on aquatic beetles that have been neglected for about 40 years, and to prepare a revised checklist.

Four new species of Burmomiles (Coleoptera, Cantharidae) from the mid-Cretaceous Burmese amber

Here we describe four new fossil species of soldier beetles, Burmomiles brevicollis sp. nov., B. angustipennis sp. nov., B. recticollis sp. nov., B. dentatus sp. nov., which are collected from the mid-Cretaceous amber in Kachin (Hukawng valley) of Northern Myanmar. They are placed in Burmomiles Fanti, Damgaard et Ellenberger, 2018 based on the male antennomeres IV‒X each with an antennal appendage inserted at a basal cavity on the ventral side, and tibiae hardly longer than femora, tarsomeres I normal and less than twice as long as II. Moreover, with more species added, the key for the identification of all Burmomiles species is updated. These results will significantly expand our knowledge on the species diversity of Burmite cantharids.

SPECIES DIVERSITY OF PULSE BEETLE IN FOUR MAJOR GRAIN LEGUMES IN ANDHRA PRADESH

Studies were carried in kharif, 2022 to know the species diversity of pulse beetles infesting  stored grain legumes in Krishna zone of Andhra Pradesh.The pulse beetles were identified as Callosobruchus maculatus and C. chinensis based on their morphological characters. A total of 1391 adults of C. maculatus were observed in blackgram. About 737 and 473 individuals of C. maculatus were recorded in greengram and chickpea, respectively. A total of 566 individuals of C. maculatus and 241 individuals of C. chinensis were found in pigeonpea grains collected from the different storage godowns. The diversity indices for pulse beetle species in pigeonpea were calculated. The Shannon- Wiener index was 2.712, indicating moderate diversity.The species evenness was 0.6273 suggesting that the evenness among the species was zero and the Margalef index was 3.436 indicating relatively high species richness.

Cephalodesmius carminya, a new flightless dung beetle species from the Central Mackay Coast, Queensland.

A new species from the genus Cephalodesmius Westwood (Coleoptera: Scarabaeidae: Scarabaeinae) is described from the Cental Mackay Coast bioregion, Queensland extending the northern range of the genus. Cephalodesmius carminya Ebert & Gunter new species is known from two localities in the Pine Mountain, Carminya Forest Reserve and 2.5 km west of Eungella dam. A key to the four species of Cephalodesmius is provided and we discuss morphological similarities between Cephalodesmius and its closest relative Canthonosoma Macleay.

Evolution, types, and distribution of flight control devices on wings and elytra in bark beetles

Gaining the ability to fly actively was a ground-breaking moment in insect evolution, providing an unprecedented advantage over other arthropods. Nevertheless, active flight was a costly innovation, requiring the development of wings and flight muscles, the provision of sufficient energetic resources, and a complex flight control system. Although wings, flight muscles, and the energetic budget of insects have been intensively studied in the last decades, almost nothing is known regarding the flight-control devices of many crucial insect groups, especially beetles (Coleoptera). Here, we conducted a phylogenetic-informed analysis of flight-related mechanosensors in 28 species of bark beetles (Curculionidae: Scolytinae, Platypodinae), an economically and ecologically important group of insects characterized by striking differences in dispersal abilities. The results indicated that beetle flight apparatus is equipped with different functional types of mechanosensors, including strain- and flow-encoding sensilla. We found a strong effect of allometry on the number of mechanosensors, while no effect of relative wing size (a proxy of flight investment) was identified. Our study constitutes the first step to understanding the drivers and constraints of the evolution of flight-control devices in Coleoptera, including bark beetles. More research, including a quantitative neuroanatomical analysis of beetle wings, should be conducted in the future.

Bark and ambrosia beetles on native and transplanted dead wood along an altitudinal tropical forest gradient

AbstractGlobal warming is expected to shift the distribution ranges of many species towards higher latitudes and altitudes. This will rewire plant‐herbivore food webs as new combinations of herbivore species encounter novel host plants. We investigated the effects of a simulated altitudinal shift in an herbivore‐host community of bark and ambrosia beetles on fig trees in a tropical mountain forest on Mt. Wilhelm, Papua New Guinea. We reared beetles from wood baits cut from five local Ficus species in their natural altitudinal ranges, between 200 and 1700 m a. s. l. Further, we transplanted baits from three of these tree species 500 m below the limits of their natural distribution range, to simulate a mean temperature increase of 2.7°C. Beetle species richness declined, and their species composition changed with increasing elevation. Furthermore, while altitude explained a large proportion of variance in beetle composition, host tree species was more important for bark beetles than ambrosia beetles. Beetle communities that assembled on the transplanted baits were similar in diversity and host specificity to those on the fig trees native to the same elevation, but also contained a number of unique species. Overall, these results indicate that saproxylic beetles in this tropical forest are highly resilient and flexible to the potential effects of climate change.Abstract in Česky is available with online material.

Genetic diversity and population structure of the endangered saproxylic beetle L. cervus in a fragmented landscape

Abstract Despite the significance of saproxylic beetle species for ecosystems, the investigation of fine‐scale population genetics within the stag beetle, Lucanus cervus, remains notably limited. Because of their limited dispersal distances and habitat fragmentation, high genetic structure and low genetic diversity are expected in its populations. To evaluate the impact of habitat fragmentation on genetic diversity and structure, we examined 150 specimens of L. cervus from three sites in western Poland: two forest stands and one stand located in an Oak avenue. We utilised 19 microsatellite DNA loci for this examination. Results of neighbour‐joining analysis and principal coordinates analysis, values of differentiation indexes (G'ST, D(Jost) and FST) and rare/private allele frequencies indicated weak genetic differentiation among individuals collected from the tree sites. A spatial component to the genetic structure was identified through STRUCTURE (LOCPRIOR), isolation by distance tests and spatial autocorrelation analysis. The genetic diversity remained relatively high (HE: 0.49–0.51), with no inbreeding observed and no significant differences in mean relatedness among individuals from sampling sites. Limited genetic differentiation between the individuals of L. cervus from the investigated sites may result from a lag time since fragment isolation, unrestricted gene flow and marker/sample size limitations. Though weak, the significant differentiation between two of the sites may be linked to environmental differences and distance. Genetic data support treating individuals from forests as a single management unit. Non‐invasive sampling suffices for genetic studies, but achieving balanced sampling is crucial for precise historical demography estimates of endangered species.

Interaction between regional temperature and shade level shapes saproxylic beetle communities

AbstractAimThe ‘concept of relative constancy of habitats’ assumes that species differ in their habitat preferences depending on the regional temperature so that all populations experience similar microclimatic conditions. Our aim was to assess the relevance of this concept by disentangling the effects of shade level and regional temperature on southern and northern distributed saproxylic (=dead wood dependent) beetle species.LocationSweden.MethodsWe established a field experiment by placing 435 logs of Norway spruce (Picea abies) along shade gradients in six regions differing in regional temperature (along a 1200 km latitudinal gradient). For each log, we sampled the saproxylic beetle community and calculated the Community Temperature Index (CTI), indicating to what extent the community is dominated by southern or northern species.ResultsSpecies richness and total abundance were better explained by shade level, whereas species composition was better explained by study region. In colder regions, CTI varied along the shade gradient, whereas in warmer regions, CTI was more similar along the shade gradient. Moreover, in colder regions, the number of southern species was higher in sun‐exposed logs, whereas in warmer regions, the number of southern species was higher in shaded logs. This supports the concept of relative constancy of habitats. In contrast, northern species preferred shaded conditions regardless of the regional temperature.Main ConclusionsRegional temperature, shade level and resulting microclimate are important drivers of species richness, total abundance and composition. Occurrence patterns of saproxylic beetle species follow to some extent the concept of relative constancy of habitats since their habitat preferences vary with regional temperature. Northern species are of conservation concern due to disadvantages by climate warming and clear‐cutting. They are favoured by preserving forests with rarely disturbed canopies.

Species delimitation, discovery and conservation in a tiger beetle species complex despite discordant genetic data

In an age of species declines, delineating and discovering biodiversity is critical for both taxonomic accuracy and conservation. In recent years, there has been a movement away from using exclusively morphological characters to delineate and describe taxa and an increase in the use of molecular markers to describe diversity or through integrative taxonomy, which employs traditional morphological characters, as well as genetic or other data. Tiger beetles are charismatic, of conservation concern, and much work has been done on the morphological delineation of species and subspecies, but few of these taxa have been tested with genetic analyses. In this study, we tested morphologically based taxonomic hypotheses of polymorphic tiger beetles in the Eunota circumpicta (LaFerté-Sénectère, 1841) species complex using multilocus genomic and mtDNA analyses. We find multiple cryptic species within the previous taxonomic concept of Eunota circumpicta, some of which were historically recognized as subspecies. We found that the mtDNA and genomic datasets did not identify the same taxonomic units and that the mtDNA was most at odds with all other genetic and morphological patterns. Overall, we describe new cryptic diversity, which raises important conservation concerns, and provide a working example for testing species and subspecies validity despite discordant data.

Indirect effects of low-impact thinning on insect communities in forest floor of coniferous plantations

ABSTRACT To reveal the effects of low-impact thinning of coniferous planted forests on insects’ diversity, we investigated the relationship among cover degree and the number of plant species and the number of insect species in eight functional groups of herbivorous beetles, ants and carabid beetles at 63 sites of Japanese cedar and cypress which were thinned or unthinned and located in the middle of Japan. We found that when low thinning was applied to approximately 30% of the stand density, the number of plant species increased from the following year, and cover degree moderately increased in the years following thinning, although canopy openness did not significantly change. Using structural equation modeling, we found that the number of herbivorous beetle species increased with the cover degree increment of feeding-intended plants (woody-plants and herbs/vines) in the 4–8 years after thinning. The number of species of woody-plant feeding beetles also increased with an increase in the number of herb/vine plant species. For ant species, the number of habitat generalist species increased in the 4–8 years after thinning or with cover degree increment, although no response was observed in woodland specialist and open-habitat specialist species. For carabid beetle species, only the number of large-size species, not including open-habitat specialists, increased with cover degree increment. It was considered that there were moderate, and yet sustainable, positive effects of low-impact thinning on species diversity of forest-floor-inhabiting insects via understory vegetation increment with a lag-time, and no promotion of migration of non-forest-habitat ant and carabid beetle species.

How host species and body part determine the microbial communities of five ambrosia beetle species.

The ambrosia beetles are farming insects that feed mainly on their cultivated fungi, which in some occasions are pathogens from forest and fruit trees. We used a culture-independent approach based on 16S and 18S rRNA gene metabarcoding analysis to investigate the diversity and composition of the bacterial and fungal communities associated with five ambrosia beetle species: four species native to America (Monarthrum dimidiatum, Dryocoetoides capucinus, Euwallacea discretus, Corthylus consimilis) and an introduced species (Xylosandrus morigerus). For the bacterial community, the beetle species hosted a broad diversity with 1,579 amplicon sequence variants (ASVs) and 66 genera, while for the fungal community they hosted 288 ASVs and 39 genera. Some microbial groups dominated the community within a host species or a body part (Wolbachia in the head-thorax of E. discretus; Ambrosiella in the head-thorax and abdomen of X. morigerus). The taxonomic composition and structure of the microbial communities appeared to differ between beetle species; this was supported by beta-diversity analysis, which indicated that bacterial and fungal communities were clustered mainly by host species. This study characterizes for the first time the microbial communities associated with unexplored ambrosia beetle species, as well as the factors that affect the composition and taxonomic diversity per se, contributing to the knowledge of the ambrosia beetle system.