Lucanidae Research Articles

A new species of Prosopocoilus Hope amp; Westwood, 1845 from China and Vietnam (Coleoptera: Lucanidae: Lucaninae).

A new species of stag beetle, Prosopocoilus zhuchuangi new species (Coleoptera: Lucanidae: Lucaninae) is described from China (Guizhou) and Vietnam. It is closely related to P. fulgens (Didier, 1927), sharing a fringe of dense setae in the apical 2/3 of the mesal sides of the mesotibiae and metatibiae. Diagnostic characters of the two species are illustrated and compared.

Lateral Transmission of Yeast Symbionts Among Lucanid Beetle Taxa.

To deepen understanding the evolutionary process of lucanid–yeast association, the lateral transmission process of yeast symbionts among stag beetle genera Platycerus and Prismognathus around the border between Japan and South Korea was estimated based on molecular analyses and species distribution modelings. Phylogenetic analyses were based on yeast ITS and IGS sequences and beetle COI sequences using Prismognathus dauricus from the Tsushima Islands and Pr. angularis from Kyushu, Japan, as well as other sequence data from our previous studies. The range overlap based on the species distribution model (SDM) and differentiation in ecological space were analyzed. Based on the IGS sequences, Clade II yeast symbionts were shared by Platycerus hongwonpyoi and Pr. dauricus in South Korea and the Tsushima Islands, and Platycerus viridicuprus in Japan. Clade III yeasts were shared by Pr. dauricus from the Tsushima Islands and Pr. angularis in Japan. During the Last Interglacial period when the land bridge between Japan and the Korean Peninsula existed, range overlap was predicted to occur between Pl. viridicuprus and Pr. dauricus in Kyushu and between Pr. dauricus and Pr. angularis in Kyushu and the Tsushima Islands. The ecological space of Pl. hongwonpyoi was differentiated from that of Pl. viridicuprus and Pr. angularis. We demonstrated the paleogeographical lateral transmission process of Scheffersomyces yeast symbionts among lucanid genera and species: putative transmission of yeasts from Pr. dauricus to Pl. viridicuprus in Kyushu and from Pr. angularis to Pr. dauricus in Kyushu or the Tsushima Islands. We also found that the yeast symbionts are likely being replaced in Pr. dauricus on the Tsushima Islands. We present novel estimates of the lateral transmission process of microbial symbionts based on phylogenetic, SDM and environmental analyses among lucanid beetles.

Characterization of the complete mitochondrial genome of Pseudorhaetus sinicus Boileau, 1899 (Coleoptera: Lucanidae)

Pseudorhaetus sinicus is a stag beetle common to China and Vietnam, but whose distribution is limited within China. Little is known about the molecular biological characteristics of this species, so we characterized its complete mitochondrial genome (GenBank accession number MZ504793.1). The mitogenome consists of a circular DNA molecule of 18,126 bp, with 67.693% AT content. It contains 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes. The PCGs have typical ATN (Met) start codons and TAN stop codons. Phylogenetic analysis suggests that P. sinicus is closely related to Prosopocoilus confucius. This newly described mitochondrial genome provides a valuable resource for the phylogenetic analysis of Lucanidae beetles.

Feeding performance of the larval stag beetle Aegus chelifer (Coleoptera: Lucanidae) explains adult body size variation and sexual dimorphism

Abstract In stag beetle larvae, food availability is considered a major cause of body size variation in adults, but this has not been explicitly tested. To evaluate wood use and the effects of food quantity on growth and adult body size, the feeding performance of the tropical stag beetle Aegus chelifer MacLeay (Coleoptera: Lucanidae), which is widely distributed in Southeast Asia, was investigated by rearing larvae with different food quantities. Apparent digestibility was approximately 9%, and the efficiency of conversion of ingested food ranged from 0.7% to 1.7%. Feeding period, total food consumption, and adult body size significantly increased alongside food quantity. Males had higher consumption rates than females did at the same larval weight due to shorter food retention time. Males showed greater variation in feeding, growth performance, and adult body size than females. Differences in feeding performance that depend on food availability may enhance their fitness and may further result in sexual differences and adult body size variation.

The European Stag Beetle (Lucanus cervus) Monitoring Network: International Citizen Science Cooperation Reveals Regional Differences in Phenology and Temperature Response

Simple SummaryInternational cooperation is needed to prevent the loss of threatened species. To evaluate the situation, standardised monitoring is an important tool. Involving the general public (citizen science) can play a crucial role in realising such international monitoring. Here we report on the start-up and initial findings of the European Stag Beetle Monitoring Network (ESBMN), an international network of stag beetle (Lucanus cervus) monitoring schemes using the same protocol. This network aims to regularly assess local and international changes in the population of the stag beetle. Therefore, an internationally standardised protocol was agreed and a website was created where volunteers can create a transect and submit the data of their transect walks. Currently, the number of transects and transect walks submitted is increasing annually and will soon allow trend analysis. Our initial experience with the ESBMN shows that volunteers need more guidance and encouragement to avoid them dropping out of the project. In conclusion, we believe this system of international cooperation can be used for other charismatic insects in order to evaluate their threatened status and plan conservation actions.To address the decline in biodiversity, international cooperation in monitoring of threatened species is needed. Citizen science can play a crucial role in achieving this challenging goal, but most citizen science projects have been established at national or regional scales. Here we report on the establishment and initial findings of the European Stag Beetle Monitoring Network (ESBMN), an international network of stag beetle (Lucanus cervus) monitoring schemes using the same protocol. The network, started in 2016, currently includes 14 countries (see results) but with a strong variation in output regarding the number of transects (148 successful transects in total) and transect walks (1735). We found differences across European regions in the number of stag beetles recorded, related to phenology and temperature, but not for time of transect start. Furthermore, the initial experiences of the ESBMN regarding international cooperation, citizen science approach, and drop-out of volunteers is discussed. An international standardised protocol that allows some local variation is essential for international collaboration and data management, and analysis is best performed at the international level, whereas recruiting, training, and maintaining volunteers is best organised locally. In conclusion, we appeal for more joint international citizen science-based monitoring initiatives assisting international red-listing and conservation actions.

When perception isn’t reality: allometric variation in the exaggerated mandibles of male stag beetles (Coleoptera: Lucanidae)

Abstract A variety of protocols have been used to study allometric variation in size of the exaggerated mandibles on male stag beetles. Many of these protocols entail logarithmic transformation of the original measurements followed by numerical analysis of the transformations by linear regression or some conceptual extension thereof. I reanalysed data from four such studies to show how these protocols can lead investigators to conclusions that are not well supported by the original observations. One of the data sets was originally reported to conform to simple loglinear allometry, with untransformed observations that presumably follow the path of a two-parameter power function; one was said to represent biphasic, loglinear allometry, with two distinctive morphs having different scaling relationships on the arithmetic scale; and two were originally described as cases of discontinuous, loglinear allometry caused by dimorphisms. My analyses, which were based on graphical analysis and nonlinear regression of untransformed observations, revealed that all the data sets form S-shaped distributions and that each of the distributions is well described by a four-parameter sigmoid function. None of the bivariate distributions reveals a discontinuity or dimorphism. Thus, the original authors unknowingly offered descriptions and interpretations for patterns of variation that do not exist in their data.

Incipient speciation and its impact on taxonomic decision: a case study using a sky island sister-species pair of stag beetles (Lucanidae: Lucanus)

Abstract Species delimitation can be difficult when the divergence between focal taxa is in the incipient stage of speciation, because conflicting results are expected among different data sets, and the species limits can differ depending on the species concept applied. We studied speciation history and investigated the impact on taxonomic decision-making when using different types of data in a Taiwanese endemic sister-species pair of stag beetles, Lucanus miwai and Lucanus yulaoensis, from sky island habitats. We showed that the two geographical taxa can be diagnosed by male mandibular shape. We found two mitochondrial co1 lineages with pairwise sequence divergence > 3%; however, L. miwai might not be monophyletic. The result of our multispecies coalescent-based species delimitation using five nuclear loci supported the evolutionary independence of the two sister species, but the calculated values of the genealogical divergence index (gdi) corresponded to the ambiguous zone of species delimitation. We also showed that post-divergence gene flow is unlikely. Our study demonstrates challenges in the delineation of incipient species, but shows the importance of understanding the speciation history and adopting integrative approaches to reconcile seemingly conflicting results before making evolutionarily relevant taxonomic decisions.

Eurasian Eagle Owls Bubo bubo Opportunistically Prey on Stag Beetles Lucanus cervus

We report an exceptional case of Eurasian Eagle Owls Bubo bubo feeding on Stag Beetles Lucanus cervus in Germany, with the beetles making up 56.9% of all prey individuals. A review of literature and a comparison of data reveal that both the number and the biomass of the consumed beetles are typically too low to be of any nutritional importance with respect to the Eurasian Eagle Owl's broad food spectrum. Therefore, we conclude that Eurasian Eagle Owls merely opportunistically fed on this only seasonally available food source and that juvenile owls might prey on these beetles during their hunting exercises.

Characterization of the immune hemocyte in larvae of Dorcus titanus castanicolor (Motschulsky, 1861) (Lucanidae, Coleoptera)

AbstractThere are four types of hemocytes in the stag beetle hemolymph: granulocytes, prohemocytes, coagulocytes, and spherulocytes. Unusually, the size and shape of the hemocyte subtypes are similar. To identify the predominant immune hemocytes, we injected carboxylate‐modified polystyrene latex beads and E. coli particles into the hemocoel of stag beetles. In response to the pathogens, only granulocytes underwent morphological changes, including the extension of fan (or amoeba)‐like structures from their membrane, and had bacterial particles in their cytoplasm. At 6 h post‐injection, lysosomes in the cytoplasm of the granulocytes were activated to remove the pathogens. At 12 h post‐injection, more lysosomes were activated along with phagocytosis of the E. coli particles. At 24 h to 48 h post‐injection, the bacterial particles, including activated lysosomes, were gradually cleared from the cytoplasm. To confirm these results, we performed flow cytometry analysis. Consistent with our microscope observations, the granulocytes were activated after 6 h post‐infection, and lysosomes were mostly activated at 12 h. These results suggest that bacteria are actively engulfed between 6 and 12 h post‐infection by granulocytes. Granulocyte lysosomes were activated within 12 h to digest the bacteria, which were completely cleared by 48 h post‐infection.

Discovery of Hyperactive Antifreeze Protein from Phylogenetically Distant Beetles Questions Its Evolutionary Origin.

Beetle hyperactive antifreeze protein (AFP) has a unique ability to maintain a supercooling state of its body fluids, however, less is known about its origination. Here, we found that a popular stag beetle Dorcus hopei binodulosus (Dhb) synthesizes at least 6 isoforms of hyperactive AFP (DhbAFP). Cold-acclimated Dhb larvae tolerated −5 °C chilled storage for 24 h and fully recovered after warming, suggesting that DhbAFP facilitates overwintering of this beetle. A DhbAFP isoform (~10 kDa) appeared to consist of 6−8 tandem repeats of a 12-residue consensus sequence (TCTxSxNCxxAx), which exhibited 3 °C of high freezing point depression and the ability of binding to an entire surface of a single ice crystal. Significantly, these properties as well as DNA sequences including the untranslated region, signal peptide region, and an AFP-encoding region of Dhb are highly similar to those identified for a known hyperactive AFP (TmAFP) from the beetle Tenebrio molitor (Tm). Progenitor of Dhb and Tm was branched off approximately 300 million years ago, so no known evolution mechanism hardly explains the retainment of the DNA sequence for such a lo­ng divergence period. Existence of unrevealed gene transfer mechanism will be hypothesized between these two phylogenetically distant beetles to acquire this type of hyperactive AFP.

Abundance, distribution and substrate association of Hong Kong stag beetles (Coleoptera: Lucanidae) in secondary forests

Abstract Ecological studies conducted on lucanids in Asia are limited, resulting in considerable knowledge gaps in the fundamental ecology of these charismatic species (e.g. larval substrate associations), despite their potential importance in wood decomposition. We conducted 25 transect surveys in secondary forest sites in Hong Kong and sampled wood parameters and site‐level wood availability data to test whether these habitat features significantly affected abundance or occurrence of lucanids. Out of 412 wood fragments sampled, we found two species: Prosopocoilus oweni was broadly distributed across sites (but still uncommon at the level of wood fragments occurring in 6.07%) while Nigidius sinicus was comparatively rarer (occurring in 0.73% of examined wood fragments). The dominant species P. oweni was more likely to appear in wood fragments in later decay stages and can be classified as a secondary forest generalist with respect to wood resource utilisation. The surveys failed to detect four additional lucanid species known in Hong Kong (Neolucanus sinicus, E. gracilis, P. biplagiatus, and Aegus chelifer) potentially because of their rarity or usage of other habitats or microhabitats. Protection of existing secondary forests in Hong Kong is recommended to secure supply of suitable habitat and resources. Results obtained by standardised surveys can furthermore serve as a baseline for future assessment of lucanid population change. This study provides ecological insights into lucanids within secondary forest ecosystems of subtropical and tropical Asia.

Endoscopic Treatment of Zenker's Diverticulum: Comparable Treatment Outcomes in Treatment-Naïve and Pretreated Patients.

Background and Aims Flexible endoscopic treatment plays an important role in the treatment of Zenker's diverticulum (ZD). This study analyzes long-term symptom control and the rate of adverse events in treatment-naïve patients and patients with recurrence, using the stag beetle knife junior (sb knife jr). Methods From August 2013 to May 2019, 100 patients with symptomatic ZD were treated with flexible endoscopy using the sb knife jr. Before treatment, as well as 1 and 6 months afterwards, symptoms were obtained by a nine-point questionnaire, with symptoms weighted from 0 to 4. Results Overall, 126 interventions were performed. The median follow-up period was 41 months (range 7-74). For the three most frequent symptoms, regurgitation, dysphagia, and dry cough, a significant reduction of the mean score could be achieved, from 2.85/3.45/2.85 before the initial treatment to 0.56/1.09/0.98 6 months later. 17 patients were retreated because of recurrence. Out of these, 12 patients underwent a 2nd, 4 patients a 3rd, and 1 patient a 4th session, respectively. The mean dysphagia score for successfully treated patients could be reduced from initially 2.34 to 0.49/0.33/0.67 after the 1st/2nd/3rd session, the frequency of dysphagia from 3.45 to 0.92/1.00/1.33, and the score for regurgitations from 2.85 to 0.35/1.00/0.67. In first-line treatment, as well as in retreatment, no severe adverse event occurred. Conclusion Patients with ZD can be treated safely and effectively with the sb knife jr. Retreatment leads to equal symptom relief as compared to a successful first-line treatment and is not associated with a higher rate of adverse events.

A multilocus assessment reveals two new synonymies for East Asian Cyclommatus stag beetles (Coleoptera, Lucanidae).

Cyclommatus scutellaris Möllenkamp, 1912, Cyclommatus elsae Kriesche, 1921 and Cyclommatus tamdaoensis Fujita, 2010 are East Asian stag beetle species with long-debated taxonomic relationships due to high intraspecific morphological variability. In this study, we applied multilocus phylogenetic analyses to reassess their relationships. Two mitochondrial genes (16S rDNA, COI) and two nuclear genes (28S rDNA, Wingless) were used to reconstruct the phylogeny through the Bayesian inference (BI) and Maximum Likelihood (ML) methods. Both topologies supported two clades: the clade C. scutellaris was sister to the clade (C. elsae + C. tamdaoensis) with the subclade C. tamdaoensis embedded in the subclade C. elsae. The Kimura 2-parameter (K2P) genetic distance analysis yielded a low mean value (≤0.035) among the three taxa, which was well below the minimum mean value between other Cyclommatus species (≥0.122). We also compared the accuracy and efficiency of two approaches, GMYC and ABGD, in delimitating the three lineages. The result shows that ABGD is a better approach than GMYC. Our molecular data recognizes the three species as different populations of a single species, ranging from Taiwan Island to the continent. Therefore, we propose two new junior synonyms for C. scutellaris: C. tamdaoensis, syn. nov. and C. elsaesyn. nov.

Relative Contribution of Citizen Science, Museum Data and Publications in Delineating the Distribution of the Stag Beetle in Spain.

Simple SummaryConservation of insects requires a reliable knowledge of their distribution. Such knowledge is hard to obtain in many cases, due to lack of human power and funding for extensive surveys. Three ways out of this problem have been suggested: (1) data already available in museum collections, (2) data already available in the entomological literature and (3) use of citizen science projects as a cheap, efficient way to survey extensive territories. We assessed the contribution of each of these sources of information in delineating the Spanish distribution of the European stag beetle. Although citizen science quickly contributed more grid cells than the other sources, some grid cells were uniquely contributed by museum and publication data. Thus, the three sources of information need to be combined when targeting endangered species in a broad, heterogenous, sparsely populated territory such as Spain.Reliable distribution maps are in the basis of insect conservation, but detailed chorological information is lacking for many insects of conservation concern (the Wallacean shortfall). Museum collections, entomological publications and citizen science projects can contribute to solve this Wallacean shortfall. Their relative contribution to the knowledge on the distribution of threatened insects has been scarcely explored, but it is important given that each of these three sources of information has its own biases and costs. Here we explore the contribution of museum data, entomological publications and citizen science in delineating the distribution of the European stag beetle in Spain. Citizen science contributed the highest number of records and grid cells occupied, as well as the highest number of grid cells not contributed by any other information source (unique grid cells). Nevertheless, both museum data and publications contributed almost 25% of all unique grid cells. Furthermore, the relative contribution of each source of information differed in importance among Spanish provinces. Given the pros and cons of museum data, publications and citizen science, we advise their combined use in cases, such as the European stag beetle in Spain, in which a broad, heterogeneous, sparsely populated territory has to be prospected.

Biology and conservation of the European stag beetle: recent advances and lessons learned

Abstract Reliable information for the conservation of many insects is lacking due to a poor knowledge of their ecology. Here, we review the biological knowledge about the European stag beetle (Lucanus cervus), in which recent advances are improving the basis for successful conservation. A review of the biological and ecological literature about this species identified an exponential increase in both total and peer‐reviewed articles after Natura 2000 regulations. Recent progress in the last two decades has been made in solving taxonomic problems, as well as in habitat description through radiotelemetry and habitat models. Dependence on large old‐growth forest has given place to a more complex picture of habitat use along the distribution range of this species. Monitoring protocols have been developed that will allow to assess conservation status and actual decline. Stag beetle conservation would benefit from a better understanding of larval demography, quantification of microhabitat requirements, landscape genetics and quantification of historical and current threats. Lessons learned include the need to solve taxonomic problems and to target methodological bottlenecks. The stag beetle is one of the few European saproxylic organisms that can engage the broad public through outreach activities and therefore its role as an umbrella species should be promoted.

Divergence in Gut Bacterial Community Structure between Male and Female Stag Beetles Odontolabis fallaciosa (Coleoptera, Lucanidae).

Simple SummaryIntestinal microbiota play crucial roles for their hosts. Odontolabis fallaciosa shows striking sexual dimorphism and male trimorphism, which represents an interesting system to study their gut microbiota. We have compared the intestinal bacterial community structure between the two sexes and among three male morphs of O. fallaciosa. The gut bacterial community structure was significantly different between males and females. The females were associated with higher bacterial alpha-diversity relative to males. Large males had a higher relative abundance of Firmicutes and Firmicutes/Bacteroides (F/B) ratio, which contributed to nutritional efficiency. The results increased our understanding of beetle–bacterial interactions of O. fallaciosa between the two sexes, and among three male morphs, which might reveal the relationship among the gut microbiota, nutrition level, and phenotypic evolution of the stag beetle.Odontolabis fallaciosa (Coleoptera: Lucanidae) is a giant and popular stag beetle with striking sexual dimorphism and male trimorphism. However, little is known about their intestinal microbiota, which might play an indispensable role in shaping the health of their hosts. The aim of this study was to investigate the intestinal bacterial community structure between the two sexes and among three male morphs of O. fallaciosa from China using high-throughput sequencing (Illumina MiSeq). The gut bacterial community structure was significantly different between males and females, suggesting that sex appeared to be the crucial factor shaping the intestinal bacterial community. Females had higher bacterial alpha-diversity than males. There was little difference in gut bacterial community structure among the three male morphs. However, compared to medium and small males, large individuals were associated with the higher relative abundance of Firmicutes and Firmicutes/Bacteroides (F/B) ratio, which might contribute to nutritional efficiency. Overall, these results might help to further our understanding of beetle–bacterial interactions of O. fallaciosa between the two sexes, and among the three male morphs.

Dispersal constraints on the potential distribution of cold‐adapted stag beetles (genus Platycerus) in Japan and the implications of climate change

Abstract The effects of climate change on species distribution are typically inferred based on species distribution models (SDMs) that do not account for the dispersal ability of species. Here we investigated the utility of dispersal ability measures in predicting the distribution of 10 Platycerus species in Japan, which are cold‐adapted stag beetles sharing ecological and morphological features. We generated three SDMs based on environmental variables without dispersal constraint and incorporating two alternative dispersal constraint scenarios. We compared these three models with respect to SDM performance and the predicted degree of range overlap between neighbouring species. Using the best models among three SDMs, we predicted range shifts under climate change. Additionally, we characterised environmental differences among species distributional areas. Our results revealed that models incorporating dispersal constraints had better predictive performance. Platycerus delicatulus occupied a largest suitable habitat and P. sue had a narrow range in Japan. Most of Platycerus taxa in 2070 were predicted to lose large portions of present suitable areas. Moreover, environment was confirmed to affect the distribution of the targeted species. Incorporating dispersal ability to better understand the effects of climate change on the species ranges is a crucial step towards developing policies for insect management and conservation of vulnerable species.

Is my sdm good enough? insights from a citizen science dataset in a point process modeling framework

Citizen science programs, and particularly atlas schemes based on opportunistic biological records, are very important sources of data for species distribution models and conservation. Nevertheless, these data are prone to bias, particularly when they come from less popular or hard to detect/identify species, such as insects. With such biased data, it is important to evaluate the stability of the model predictions. In recent years, point process models (PPMs) have shown their strength as a unifying framework to fit presence-only species distribution models with many advantages in model implementation and interpretation; PPMs are closely connected to methods already in widespread use in ecology such as MaxEnt and to logistic regression and benefit from being more transparent about resource selection and absence handling. Moreover, there is a well-developed set of tools to fit these models and assess various features of the underlying model, including model stability. However, such tools are currently unavailable when point process models are fitted with a lasso penalty, which has been shown to improve predictive performance. Based on the French citizen science program “Stag beetle Quest”, we propose new methods to assess model stability in this context. The ultimate goal was to develop a set of functions to analyze PPM models with lasso penalties fitted with presence-only data. To assess model stability, we randomly sampled different subsets of locations with varying size from the whole dataset and used the proposed tools to compare fitted intensities and model coefficients. All the developed measures are complementary and can be used to identify at what number of point locations the model stabilizes, which will be dependent on the dataset. Our work presents a new toolbox to explore questions around model stability based on the number of locations in the context of point process models with a lasso penalty and confirms once more the use of the point process modeling framework as a flexible and unifying framework to fit presence-only species distribution models.

Isolation of Bursaphelenchus macromucronatus from commercialised artificial larval diet for stag beetles in Japan

Isolation of Bursaphelenchus macromucronatus from commercialised artificial larval diet for stag beetles in Japan

EPIZOOTIC SITUATION ON TREMATODES OF MARALS IN THE ALTAI REGION AND THE EFFECTIVENESS OF AN ANTI-TREMATODE DRUG IN PRODUCTION EXPERIENCE

Altai Region has always been and remains a region of developed animal husbandry. Velvet antler industry is an integral part of it. It specializes in the breeding of marals and sika deer. One of the main problems encountered in maral breeding is the infection of animals with helminths. The resistance of helminths to various environmental conditions without loss of invasiveness, as well as anthelmintic treatments is carried out, as a rule, with the same drugs from the group of macrocyclic lactones. They do not have a sufficient destructive effect on the causative agents of parasitic diseases (in particular, on trematodes) and promote helminths circulation and their distribution. In this regard, we set a goal: to analyze the epizootic situation in terms of trematodes of marals in the farms of the Altai Region and to study the effectiveness of the antiparasitic action of the drug Santel 10%. In the course of clarifying the epizootic situation on trematodosis of marals in the main maral breeding areas of the Altai Region, it was established that this group is currently represented by the causative agent of dicroceliosis. In general, over the period of research, the invasion of marals by the causative agent of dicroceliosis tended to slightly decrease in terms of the extent of invasion - by 20%. An experiment in the study of the anti-trematode efficacy of the drug Santel 10% by OOO VIK-Animal Health (Russia), was carried out on stag beetles in the Altai Territory of the Altai Region. As a result of production experience on the use of the drug Santel 10% on spontaneously infested marals, it was revealed that the drug is effective against dicrocelia, in particular, in terms of intensity efficiency, which was 84.5% with an intensity efficiency of 40%.