Phylogeny of the Saprininae reveals interesting ecological shifts in the history of the subfamily (Coleoptera: Histeridae)

A morphological data set for the histerid beetle subfamily Saprininae comprising 95 adult morphological characters scored (multistate coding) from 72 terminal taxa and four outgroups was developed in order to analyse and determine the relationships amongst the genera and subgenera of the Saprininae subfamily. Cladograms were rooted with exemplars of Dendrophilinae (genus Dendrophilus), Bacaniini (genus Bacanius), Abraeinae (genus Chaetabraeus), and Anapleini (genus Anapleus). Parsimony‐based phylogenetic analyses were performed based on the type species of each genus and subgenus of the Saprininae occurring around the world, with the exception of three taxa: Paramyrmetes foveipennis (type species of the genus Paramyrmetes), Satrapister nitens (type species of the genus Satrapister) and Xerosaprinus (Auchmosaprinus) laciniatus (type species of the subgenus Auchmosaprinus) that were not available. In addition, in order to test the monophyly of several questionable genera, multiple exemplars were added in a few cases. The analysis also included an exemplar of an apparently undescribed genus. The results of the analysis confirm the monophyly of the subfamily supported by two unique synapomorphies: (1) presence of sensory structures of the antenna; and (2) presence of the antennal cavity, as well as several other weaker synapomorphies. However, the phylogeny inferred here shows mostly low support for the deeper branches and consequently no major changes in the Saprininae classification are proposed. The presented cladogram is discussed together with its implications for the evolution of the subfamily. The most informative characters and their respective states are outlined. Multiple shifts in lifestyles have evolved during the evolutionary history of the group. Taxa found near the root of the cladogram are mostly nidicolous or myrmecophilous, and inquiliny is presumed to be the plesiomorphic lifestyle of the subfamily. The nidicolous lifestyle has undergone several transformations to other lifestyles and myrmecophily has evolved three times independently during the evolution of the subfamily. Termitoxeny has evolved two times independently in the group whereas ecological adaptation for life in caves has likewise evolved two times independently. The analyses yielded a large clade of predominantly psammophilous taxa; psammophily is thought to have evolved once and has been subsequently lost several times. © 2014 The Linnean Society of London     

Life cycle of an endangered riffle beetle,Leptelmis gracilis Sharp (Coleoptera: Elmidae), in the Hiikawa River system,Shimane prefecture,Japan

We studied the life cycle of the riffle beetle Leptelmis gracilis Sharp, 1888 from a population located in a river stream with lotic environments. Samples were collected monthly, between September 2018 and August 2019, from a tributary of the Hiikawa River in Izumo city, Shimane Prefecture, Honshu, Japan. Larvae were separated into five distinct groups based on size. The first and last instar larval sizes were identified through rearing methods. From these results, we determined that the larval stage of this species consists of five instars. From the monthly evaluations, the number of individuals corresponding to each instar period suggested that last-instar larvae were dominant in May and that new adults emerged from July to August. Landing and pupation were estimated to occur from May to June. Monthly observations revealed that mature eggs were present in the female abdomen from April to June, as well as from August to September. It is, therefore, predicted that overwintering adults mainly oviposit from spring to early summer, while new adults oviposit from late summer to early autumn.     

三种圈养草食性野生动物粪便对 粪食性金龟的引诱效果

圈养草食性野生动物产生的大量粪便堆积容易造成环境污染,且处理耗时耗力。如果能筛选、利用粪食性金龟对草食性野生动物粪便进行处理,无疑具有一定的应用价值。本研究于2019年8和9月,以南京红山森林动物园3种圈养草食性野生动物,亚洲象（Elephas maximus）、黇鹿（Dama dama）和长颈鹿（Giraffa camelopardalis）的新鲜粪便为诱饵,在南京紫金山研究了粪便对粪食性金龟的引诱效果。本实验分为2个阶段,第1阶段采用更换陷阱法,第2阶段采用放置陷阱法,采用单因素方差分析（One-way ANOVA）对粪食性金龟诱捕数量进行检验。第1阶段更换陷阱法共引诱采集粪食性金龟4 597头,隶属于1科5属7种,优势种为中华嗡蜣螂（Onthophagus sinicus）和短亮凯蜣螂（Caccobius brevis）,占总捕获量的比例分别为48.79%和30.95%。第2阶段放置陷阱法共引诱采集粪食性金龟3 512头,同样隶属于1科5属7种,物种与阶段1实验结果相同。粪食性金龟对3种野生动物粪便显示多食性特征,在3种粪便中取食活动的有效时间段主要集中在1 ~ 2 d内,活动时间较短,粪便放置第7天,基本不存在粪食性金龟的活动。粪食性金龟群落的Shannon-Wiener多样性指数和Pielou均匀度指数在亚洲象粪便中相对较高。本研究表明,动物园3种圈养草食性野生动物粪便对粪食性金龟具有较好的引诱效果,未来需进一步研究粪食性金龟对粪便的处理效果。     

Assessing the origin of Neotropical mountain dung beetle assemblages (Scarabaeidae: Scarabaeinae): the comparative influence of vertical and horizontal colonization

Aims The fauna of mountains and their surrounding regions are likely to be influenced principally by two biological processes: horizontal colonization along similar altitudinal levels by elements originating from lineages inhabiting higher latitudes; and vertical colonization by lineages from the same latitude, but at lower altitudes. We examine whether the expected patterns derived from the latter process can be observed in mountain dung beetle assemblages. Specifically, we study the variation in species composition and richness with altitude in five regions spanning elevation gradients, analysing whether the altitudinal rates of change in the number of species and genera differ, and whether beta‐diversity scores for adjacent sites in each altitudinal gradient are different for species and genera. Location Eastern Cordillera of the Colombian Andes. Methods Field work was carried out in 1997–99 at 27 sites in five regions with elevation gradients, with 10–32 pitfall traps placed in each site. For each altitudinal level the numbers of species and genera were analysed with respect to altitude, and the slope of the linear regression between these variables was calculated. The slope of the curve of the altitude against the cumulative number of species and genera was also calculated for each altitudinal gradient to describe the compositional change between adjacent sites (beta diversity). Species and generic slopes were compared using analysis of covariance. The turnover of species along each altitudinal gradient was measured using presence/absence data and Cody's beta‐diversity index between adjacent pairs of sites. A cluster analysis was used to detect faunistically homogeneous groups of localities. Results Species richness always decreased with altitude, although the slopes did not differ significantly from zero. The number of genera also decreased with increasing altitude, but generally at a significantly slower rate than for species. Variation in the species beta‐diversity scores between altitudinal levels did not follow a homogeneous pattern in the different regions. Two main altitudinal groups of sites with a boundary c. 1500–1750 m a.s.l. can be detected with respect to faunistic similarity. Low‐ and mid‐altitude sites are inhabited by all of the genera (19) and 80% of all species collected. Eight genera and 61 species (c. 60% of the total) are unable to inhabit high‐altitude sites, and only 20 species appear to be exclusive to these high‐altitude environments (> 2000 m a.s.l.). Main conclusions The dominant processes explaining dung beetle composition in the high north‐eastern Andean mountains are probably those of vertical colonization. The limited role of horizontal colonization processes, or colonization from northern or southern lineages, could be a consequence of the isolation and recent geological origin of these mountains.     

Burying beetle Nicrophorus investigator reproduction on Pacific salmon carcasses

Abstract.  1. In many undisturbed watersheds along the Pacific Rim, anadromous salmon ( Oncorhynchus spp.) provide a predictable source of carrion to the riparian zone, largely due to horizontal transfer of salmon carcasses by bears ( Ursus spp.) and other vertebrates.
2. Burying beetles are important members of the north-temperate carrion fauna, and may utilise salmon carcasses and remnants for breeding. In this study, isotopic and observational data are reported that demonstrate previously unrecognised Nicrophorus investigator (Zetterstedt) reproduction on large salmon carcasses from five watersheds in coastal British Columbia.
3. Stable isotope signatures (δ¹⁵N and δ¹³C) of adult beetles collected in autumn indicate a diet of salmon origin in all but one individual from all watersheds, suggesting that this beetle–salmon association is widespread. Comparison of autumn isotope signatures to individuals collected randomly in summer suggests that isotope signatures represent the larval carrion source from the previous autumn rather than immediate adult diet.
4. In a survey of N. investigator use of salmon carcasses from two watersheds, 35 broods were observed on chum and pink salmon carcasses, including 16 natural brood complexes containing over 100 larvae, and five ranging from 250 to 750 larvae.
5. Overall, north-coastal populations of N. investigator breed on the rich and reliable salmon resource and may exhibit a system of communal breeding on these carcasses. This is most relevant when the dramatic reduction in salmon spawning biomass over the last century is considered.     

Foraging behaviour influences the outcome of predator–predator interactions

Abstract.  1. Interactions among predators may influence the total efficiency of a predator complex. The effect of intra- and interspecific interactions of the generalist predators Orthotylus marginalis (Heteroptera: Miridae) and Anthocoris nemorum (Heteroptera: Anthocoridae) was investigated in a laboratory experiment. Outcomes of the interactions were determined by comparing predation rates on eggs and larvae of the blue willow beetle Phratora vulgatissima of single individuals with those of two individuals of the same or different species.
2. A non-additive, antagonistic effect on predation rates due to intraspecific interactions was found between individuals of A. nemorum . No such effect was found in O. marginalis . These results are as expected as a consequence of differences in behaviour of the two predator species: A. nemorum is a much more active and mobile predator than O. marginalis .
3. Contrary to expectation, interspecific interactions between A. nemorum and O. marginalis did not affect the total predation rate.
4. An observation from the field corroborated the results obtained in the laboratory study; there was no negative relationship between the densities of the two predator species, indicating that the two species do not interact negatively in the field at their natural densities.
5. It is concluded that the additive effect of multiple predator species is of potential value in biological control.     

Resistance of fast- and slow-growing subalpine fir to pheromone-induced attack by western balsam bark beetle (Coleoptera: Scolytinae)

Abstract 1 We investigated the resistance of fast‐ and slow‐growing subalpine fir to pheromone‐induced attack by western balsam bark beetle at two sites in the interior of British Columbia, Canada. 2 Attack success by the beetle and subsequent tree mortality were higher in slow‐growing trees than in fast‐growing trees. 3 Fast‐growing trees were more likely to produce secondary resin, and in greater quantities, than slow‐growing trees after attack. 4 Host vigour (indicated by recent radial growth) was positively related to the induced defense response and resistance of subalpine fir to bark beetle attack. These results are discussed in the context of plant defense and plant–herbivore interaction hypotheses. 5 Given the preference of western balsam bark beetle for weakened trees, as well as the reduced defenses and increased mortality rates in less vigorous trees, effective management tactics for this beetle may include strategies that increase the growth and vigour of its subalpine fir host.     

Pheromonally mediated mate attraction by males of the burying beetle Nicrophorus orbicollis: alternative calling tactics conditional on both intrinsic and extrinsic factors

Male burying beetles attract females using a pheromonal signaland can provide parental care and a food resource, vertebratecarrion, for their developing offspring. But males attempt toattract females even when they have no carrion. We examinedthe factors that influence male behavior directed toward findingor attracting mates in both field-caught and laboratory-reared Nicrophorusorbicollis, a North American burying beetle. We investigatedwhether male behavior differed based on both intrinsic (size)and extrinsic (resources held) differences among males. Further,we examined repeatability of individual behaviors and the effectof holding or lacking resources on these repeatabilities. Field-caughtand laboratory-reared individuals differed in overall activitybut not in their behavioral repertoire, making studies of laboratory-rearedmales relevant. The behavior of individual males was very consistentwithin a condition, but plastic between resource conditions.The frequency of calling (adopting a posture that indicatespheromone release to attract females) depended on male sizewhen males did not hold resources, but this relationship disappearedwhen males held resources. Without carrion, smaller males calledmore frequently than did larger males. When holding carrion,smaller males reduced their calling, whereas larger males significantlyincreased the frequency with which they attempted to attractfemales and reduced the amount of time they spent searching.Thus, calling behavior of males was conditional on not only intrinsicand extrinsic factors, but also an interaction between them.We suggest that the changes in calling represent alternativetactics based on the costs and benefits of attracting both potentialmates and competitors, which differ for males of different sizes.     

Spatial distribution, resource utilisation and intraspecific competition in the dung beetle Aphodius ater

Competitive interactions in northern temperate dung beetles are poorly understood. This investigation therefore comprises a series of field and experimental work on a dung beetle species common in northern Europe, Aphodius ater, with special focus on intraspecific competitive interactions. The between-pat distribution of adult A. ater in relation to the age of sheep dung pats was studied in the field. The distribution of both sexes was contagious in the fresh pats but became more regular with increasing pat age. The successional occurrence of males and females did not differ, but immature females tended to occur in fresh pats while mature females were mainly found in older pats. With increasing age of pats, the egg load of females also increased. Egg-laying behaviour of the beetles was studied in laboratory experiments. The mean number of eggs laid per female per dung pat decreased with increasing beetle density. Thus, density-dependent processes seem to regulate resource utilisation with regard to breeding behaviour, resulting in equal exploitation of the available pats. Survival and weight of recently hatched beetles decreased with increasing initial density of eggs. Hence, in A. ater, competition between larvae for food within pats does occur. Received: 4 February 1998 / Accepted: 20 April 1998