Agrilus mali Matsumara (Coleoptera: Buprestidae), a new invasive pest of wild apple in western China: DNA barcoding and life cycle

Agrilus mali Matsumara (Coleoptera: Buprestidae) is a wood‐boring beetle distributed to eastern China that occasionally injures apple species. However, this wood‐boring beetle is new to the wild apple forests (Malus sieversii) of the Tianshan Mountains (western China) and has caused extensive tree mortality. The development of a biological control program for these wild apple forests is a high priority that requires exploration of the life cycle, DNA barcoding and taxonomic status of A. mali. In this study, to determine the diversity of invasive beetles, a fragment of the mitochondrial cytochrome oxidase gene was analyzed. Based on the results, beetles from Gongliu and Xinyuan counties of Xinjiang were identical but differed from those in the apple nursery of Gongliu by a single‐nucleotide substitution. We summarize the taxonomic status, relationships, and genetic distances of A. mali among other Agrilus species using the Tajima‐Nei model in maximum likelihood phylogeny. Analysis revealed that A. mali was closely related to Agrilus mendax and both belong to the Sinuatiagrulus subgenus. The life cycle of A. mali was investigated based on a monthly regular inspection in the wild apple forests of Tianshan. Similar to congeneric species, hosts are injured by larvae of A. mali feeding on phloem tissue, resulting in serpentine galleries constructed between bark and xylem that prevent nutrient transport and leading to tree mortality. Future studies will focus on plant physiological responses to the invasive beetles and include surveys of natural enemies for a potential classical biological control program.     

Host-seeking behavior in larvae of the robber fly Mallophora ruficauda (Diptera: Asilidae)

The robber fly Mallophora ruficauda is the most important pest of apiculture in the Pampas region of Argentina. Adults prey on honeybees and other insects, while larvae parasitize larvae of scarab beetles, which live underground. Females of M. ruficauda do not search for hosts but instead lay eggs in tall pastures. Once hatched, larvae drop to the ground and burrow underground to search for their hosts. We tested in the laboratory whether larvae of M. ruficauda actively search for their hosts using host and/or host-related chemical cues. We report that M. ruficauda detects its host using chemical cues that originate in the posterior half of the host's body, most likely from an abdominal exocrine structure. This particular host-searching strategy is described for the first time in Asilidae.     

New records of nematomorph parasites (Nematomorpha: Gordiida) of ground beetles (Coleoptera: Carabidae) and camel crickets (Orthoptera: Rhaphidophoridae) in Washington State

From 1998 to 2003, beetles and crickets infected with hairworms were collected from 4 localities within the Hanford Nuclear Site and the Hanford Reach National Monument, located in a shrub-steppe region of Washington State along the Columbia River. Infected hosts comprised 6 species of carabid beetles within 5 genera and 2 camel crickets within 1 genus; all are newly documented insect-nematomorph associations. A large proportion of the infected hosts (48%) were collected from a single site during a single collecting period. Of the 38 infected hosts, 32 contained a single worm, 4 hosts contained 2 worms, and 2 hosts contained 3 worms. Five of the hosts with multiple infections contained at least 1 male and 1 female worm. Camel crickets were infected with Neochordodes occidentalis while carabids were infected with an undescribed species of Gordionus . As the majority of hairworms are collected in the post-parasitic adult phase, host data and hairworm-arthropod associations remain poorly documented and our work adds new data to this area of nematomorph biology.     

Behavioral ecology ofMyiopharus doryphorae (riley) andM. aberrans (townsend), tachinid parasitoids of the colorado potato beetle

The behavior ofMyiopharus doryphorae andM. aberrans, North American tachinid parasitoids of the Colorado potato beetle, was recorded under field and laboratory conditions throughout three growing seasons in western Massachusetts. Eight common behaviors associated with resting, searching, feeding, and larviposition were distinguished, which together accounted for nearly all daytime activity of the females of both tachinids. Several of these behaviors, and in particular larviposition, were closely related to temperature but differed between species. A sequence of five defensive behaviors by the different larval stages of the Colorado potato beetle prevented larviposition in 49% of resisted attempts and perhaps one-fourth of total larviposition attempts byMyiopharus species, yet both parasitoids were highly successful in allocating their progeny during most of the summer. Second- and third-instar beetle larvae were least effective in resisting larviposition. Females of bothMyiopharus species actively guarded recently parasitized hosts from otherMyiopharus females for a period of several minutes after larviposition during the last month of the growing season when second- and third-instar Colorado potato beetle larvae were most scarce. Laboratory studies based on the field observation that femaleM. aberrans doggedly pursued circum-diapausing adult beetles led to the first recorded account ofM. aberrans larvipositing in adult hosts. Flies gained access to a beetle’s vulnerable abdominal dorsum at the instant it lifted its elytra to initiate flight. The late-season switch ofM. aberrans to adult Colorado potato beetles contributed to a seasonal sequence of larviposition-related behaviors concordant with prevailing host densities, which should lend complementarity toM. doryphorae andM. aberrans as biological controls of pest populations.     

Distribution and hosts of Callidiellum rufipenne (Coleoptera: Cerambycidae), an asian cedar borer established in the eastern United States

The distribution and hosts of the exotic cedar-boring beetle, Callidiellum rufipenne (Motschulsky) (Coleoptera: Cerambycidae), were determined in five northeastern U.S. states by capturing adults on cedar trap logs and by rearing adults from various conifers. This beetle was detected in the coastal states of Massachusetts, Rhode Island, Connecticut, New York, and New Jersey. In these states, adults emerged from the live or dead wood of four genera and eight species of Cupressaceae; species of Pinaceae were not hosts. Through its entire range, C. rufipenne is reported to infest at least 14 species of Cupressaceae, four species of Pinaceae, and one species of Taxaceae; but, records of Pinaceae and possibly Taxaceae are suspect. Based on the number of adults that emerged from coniferous poles in a five-way choice test in the field, the infestation level was significantly greater in Chamaecyparis thyoides (L.) Britton, Sterns, and Poggenburg and Juniperus virginiana L. than in Pinus rigida Miller, Pinus strobus L., and Tsuga canadensis (L.) Carribre (last three species uninfested). In a second test of host preference in the wild, beetles infested four cupressaceous species, but not Abies balsamea (L.) Miller, Picea rubens Sargent, Pinus rigida, P. strobus, and Ts. canadensis in the Pinaceae. Infestation level was highest in Ch. thyoides, followed in decreasing order by Juniperus communis L., Thuja occidentalis L., and J. virginiana. In a comparison of live and dead J. virginiana, beetles developed to adults only in dead trees (36 beetles per tree). When trunk sections of Th. occidentalis with and without bark were offered to females in cages, beetles of the next generation emerged exclusively from wood with bark. In the Northeast, only species of Cupressaceae apparently are suitable hosts for C. rufipenne. Infestation of these species may be prevented or reduced by proper care of live plants and by debarking trees after harvesting.     

Two Human Cases Infected by the Horsehair Worm, Parachordodes sp. (Nematomorpha: Chordodidae), in Japan

The present study was performed to describe 2 human cases infected by the horsehair worm, Parachordodes sp., in Japan. Two gordiid worms were collected in the vomit and excreta of an 80-year-old woman in November 2009 in Kyoto city, and in the mouth of 1-year-old boy in December 2009 in Nara city, Japan, respectively. Both worms were males having bifurcated posterior ends and male gonads in cross sectional specimens. They were identified as Parachordodes sp. (Nematomorpha: Chordodidae) based on the characteristic morphologies of cross sections and areoles in the cuticle. DNA analysis on 18S rRNA partial sequence arrangements was also carried out and both worms were assumed to be close to the genus Paragordionus based on tree analysis, and far from Gordius sp. which has already been reported in humans in Japan. DNA sequencing of the Parachordodes worm does not appear on the database; therefore, more information on the gene sequences of the genus Parachordodes from humans, animals, or intermediates is required.     

Host range of Asobara japonica (Hymenoptera: Braconidae), a larval parasitoid of drosophilid flies

We studied the host range of Asobara japonica, a larval‐pupal parasitoid of drosophilid flies. Habitat selection was found to be an important determinant of host range in this parasitoid; it attacked drosophilid larvae breeding on banana and mushrooms, but seldom attacked those breeding on decayed leaves. This parasitoid was able to use diverse drosophilid taxa as hosts. Attack by A. japonica sometimes killed hosts at the larval stage, and therefore parasitoid larvae also died. Drosophila elegans and D. busckii suffered particularly high larval mortality due to the attack by A. japonica (in the latter species only when young larvae were attacked). Many individuals of D. subpulchrella also died at the pupal stage without producing parasitoids when they were parasitized at the late larval stage. In contrast, D. bipectinata, D. ficusphila, D. immigrans, D. formosana and D. albomicans were resistant to attack: large proportions of the larvae of these drosophilid species grew to adulthood, even in the presence of parasitoids. On the basis of phylogenetic information, we concluded that phylogenetic position has only limited importance as a factor determining whether a species is suitable as a host for A. japonica, at least within the genus Drosophila.     

Come with me if you want to live: sympatric parasites follow different transmission routes through aquatic host communities

Community composition, including the relative density of each host species, plays a vital role in the transmission of parasites or disease in freshwater ecosystems. Whereas some host species can effectively transmit parasites, others can act as dead ends (non-viable transmission routes), accumulating large numbers of parasites throughout their life, thus becoming important sinks for parasite populations. Although population sinks have been identified in certain host-parasite systems, robust field estimates of the proportions of parasites that are lost to these hosts are lacking. Here, we quantified the distribution of encysted larval hairworms (phylum Nematomorpha), common parasites in lotic ecosystems, in two subalpine stream communities of New Zealand. With parasite and host population densities calculated per m², we identified which host species most likely contributed to the transmission of three sympatric hairworm morphotypes identified in both streams, and which species acted as population sinks. We also tested for seasonal patterns and peaks in the abundance of each morphotype in the two communities over the sampling season. Finally, we tested whether hosts emerging from the streams had comparable abundances of hairworm morphotypes throughout the sampling period. For each morphotype, different key sets of host species harboured more hairworms on average (abundance) than others, depending on the stream. For one morphotype in particular, two species of hosts were found to be important population sinks that inhibited over a third of these parasites from completing their life cycle. We also observed a clear peak in abundance for another hairworm morphotype during summer. Our data suggest that hosts emerging from the streams matched their aquatic counterparts with respect to hairworm abundance, indicating no infection-dependent reduction in emergence success. Our findings suggest that, depending on relative community composition, sympatric parasites follow different host transmission pathways, some of which lead to dead ends that potentially impact overall infection dynamics. In turn, this information can help us understand the spread or emergence of disease in both freshwater and terrestrial environments, since hairworms infect terrestrial arthropods to complete their life cycle.     

Novelty and emergent patterns in sperm: Morphological diversity and evolution of spermatozoa and sperm conjugation in ground beetles (Coleoptera: Carabidae)

The beetle family Carabidae, with about 40,000 species, exhibits enough diversity in sperm structure and behavior to be an excellent model system for studying patterns and processes of evolution. We explore their potential, documenting sperm form in 177 species of ground beetles using light microscopy and collecting data on one qualitative and seven quantitative phenotypic traits. Our sampling captures 61% of the tribal-level diversity of ground beetles. These data highlight the notable morphological diversity of sperm in ground beetles and suggest that sperm in the group have dynamic evolutionary histories with much morphological innovation and convergence. Sperm vary among species in total length (48–3,400 μm), head length (0.5–270 μm), and head width (0.2–6.3 μm). Most ground beetles make sperm with heads that are indistinct from the flagella at the gross morphological level. However, some or all Omophron, Trachypachus, and Dyschiriini make broad-headed sperm that show morphological differences between species. Most ground beetles package their sperm into groups of sperm, termed conjugates, and ground beetles show variation in conjugate form and in the number and arrangement of sperm in a conjugate. Most ground beetles make sperm conjugates by embedding their sperm in a hyaline rod or spermatostyle. The spermatostyle is remarkably variable among species and varies in length from 17 to 41,000 μm. Several unrelated groups of ground beetles make only singleton sperm, including Nebriinae, Cicindelinae, many Trechinae, and the tribe Paussini. In order to study patterns in sperm evolution, we combine these data with a low-resolution phylogeny of ground beetles. Results from modern comparative analyses suggest the following: (a) sperm differ from conjugates in some aspect of their underlying evolutionary process, (b) sperm have influenced conjugate evolution and vice versa, and (c) conjugation with a spermatostyle likely evolved early within the history of Carabidae and it has been lost independently at least three times.     

Heydenius araneus n.sp. (Nematoda: Mermithidae), a parasite of a fossil spider, with an examination of helminths from extant spiders (Arachnida: Araneae)

Abstract. A mermithid, a parasite of a spider (Araneae: Thomisidae) in Baltic amber (40 mya), is described as Heydenius araneus n.sp. (Nematoda: Mermithidae) and represents the first fossil record of a nematode parasite of an arachnid. After a critical examination of reports of naturally occurring helminths of extant spiders, I conclude that although mermithid parasitism is well established in this host group, previous reports of hairworm parasites of spiders are "nomina dubia," putative records, or refer to mermithid nematodes.     

Artificial diets for rearing the coconut hispine beetle,Brontispa longissima (Coleoptera: Chrysomelidae), and their suitability to two specialist parasitoids

The coconut hispine beetle, Brontispa longissima (Gestro), is a serious invasive pest that infests young unopened fronds of coconut palms (Cocos nucifera L.) in Southeast Asia. We previously developed the first artificial diet for rearing B. longissima larvae, which contained a leaf powder of young coconut fronds. Because the fronds are required for healthy growth of coconut palms, it is necessary to reduce their use for rearing the beetles. In this study, we tested two new artificial diets for the beetle larvae, which contained the leaf powders of mature coconut leaves or orchard grass (Dactylis glomerata L.). Brontispa longissima successfully developed from hatching to adulthood on both the mature coconut leaf diet and orchard grass diet. The beetles reared on the mature coconut leaf diet and orchard grass diet developed faster than those reared on the young coconut leaf diet. Fecundity and egg hatchability of beetles did not differ among the three diet treatments. We then examined the suitability of beetle larvae or pupae reared on each diet as hosts for two specialist endoparasitoids, Asecodes hispinarum Boucek and Tetrastichus brontispae Ferriere. The survival rate from oviposition to adult emergence for A. hispinarum was 43.8% in hosts reared on a young coconut leaf diet, 77.1% on a mature coconut leaf diet, and 85.7% on an orchard grass diet. For T. brontispae, the survival rate was 70.0% in hosts reared on the young coconut leaf diet, 38.1% on the mature coconut leaf diet, and 66.7% on the orchard grass diet. Our results indicate these artificial diets can be useful for rearing B. longissima and its two parasitoids, helping to reduce the costs of mass rearing these insects.     

Effect of changes in the thermoperiod on reproductive diapause in Bruchidius atrolineatus Pic (Coleoptera: Bruchidae)

Abstract. Bruchidius atrolineatus (Pic) is a tropical bruchid developing in Vigna unguiculata (Walp) pods. Adults are in reproductive diapause during the dry season. In conditions of 40:25C or 35:25C, diapause is induced when larvae develop in thermophases longer than 14 h, in thermophases shorter than 10 h and in continuous darkness. Thermophases of 12 h cause a reduction of the proportion of diapausing beetles. This proportion also depends on the thermoperiod temperatures. Development at low temperatures (23: 16C, 12: 12 h) induces a high percentage of diapausing beetles. However, at low temperatures, the developmental times of the beetles are long and show important interindividual variability. When larvae develop in decreasing temperatures, small changes in thermoperiod temperatures (35:25C to 3O:2OC) have a strong effect on diapause induction. When larvae develop at low temperatures (25:15C) and then at high temperatures (40:25C), the proportion of diapausing beetles depends on the duration of development at low temperatures. Whatever the developmental conditions, both sexually active and diapausing beetles always emerge from the seeds. This interindividual variability is important in this species which has a wide geographical distribution in Africa.     

Interspecific discrimination and larval competition amongMicroplitis croceipes,Microplitis demolitor,Cotesia kazak (Hym.: Braconidae), andHyposoter didymator (Hym.: Ichneumonidae), parasitoids ofHeliothis virescens (Lep.: Noctuidae)

Interspecific host discrimination by adults, and larval competition among the endoparasitoidsMicroplitis croceipes (Cresson),Microplitis demolitor Wilkinson,Cotesia kazak (Telenga) andHyposoter didymator (Thunberg) were investigated usingHeliothis virescens (F.) as the host. In ovipositional choice tests, the mean number of encounters and ovipositions for unparasitized hosts was not significantly different from the mean number of encounters and ovipositions for parasitized hosts for each treatment combination (P>0.05). Thus, none of the parasitoid species discriminated between host larvae recently parasitized once by a female of another species und unparasitized hosts. However, in all but two cases, females did discriminate between unparasitized hosts and hosts in which an early first instar of the first-attacking species was developing.Cotesia kazak andH. didymator did not discriminate between unparasitized hosts and hosts parasitized by an early first instar ofM. demolitor. Larval competition among these parasitoid species was studied for three time intervals between the first and second species parasitization: 1) second species attack immediately (5–15 sec) after the first; 2) second species attack 24 h after the first; and 3) second species attack 48 h after the first. Time until egg eclosion was shortest forM. demolitor, thenC. kazak, thenM. croceipes, and longest forH. didymator. When the second parasitoid species attacked a host immediately after the first species, the species in which egg eclosion occurred first was the victor more frequently, except whenM. demolitor competed withC. kazak andH. didymator. With a 24 h delay between the first and second species to attack, the older first instar from the first parasitization usually outcompeted the younger first instar from the second attack. A first instar from the second species to attack generally outcompeted the second instar of the first species when the second parasitization had been delayed 48 h. Competiors were eliminated mainly by physical attack, butC. kazak andM. croceipes apparently also killedH. didymator eggs by physiological processes.     

Seasonal occurrence,morphology, and observations on the life history of Gordius difficilis (Nematomorpha: Gordioidea) from southeastern Wisconsin,United States

A total of 584 adult nematomorphs, Gordius difficilis, was collected from 2 man-made ponds and their overflow stream in southeastern Wisconsin. Ponds were surveyed throughout the year, but all free-living worms were found during July-August of 1996, July-September of 1997, and June-August of 1998. Overall sex ratio was male biased; however, sex ratio was variable during different months. Observations during 1998-2000 indicated that worms mated within 24-48 hr of emergence from their hosts and began laying eggs by mid-August, continuing until mid-October. Eggs with well-developed larvae were recovered during October and November. Encysted larval nematomorphs were recovered from aquatic and semiaquatic invertebrates (gastropods, earthworms, and insects), whereas developing hairworms were found in terrestrial European ground beetles Pterostichus melanarius. It is hypothesized that semiaquatic invertebrates may serve as intermediate/paratenic hosts in this system and are preyed upon by terrestrial carabid beetles, thus completing the life cycle. In addition, scanning electron microscopy observations of G. difficilis add previously unreported observations on intraspecific variation in body length, cuticle morphology, and gametes of this species. This is the first report of G. difficilis from Wisconsin as well as the first report of this species from P. melanarius and aquatic and semiaquatic invertebrates.     

Mites (Acari) phoretic on ground beetles (Coleoptera,Carabidae) in a southern taiga forest in the environs of Vologda

Ground beetles were captured in a mixed southern taiga forest near the city of Vologda, Russia, from March to September 2014 using different collection techniques. Of the 250 specimens of ground beetles belonging to 22 species, 109 beetles representing 11 species yielded 326 specimens of mites of the cohorts Gamasina (4 species), Astigmatina (5), and Heterostigmatina (1). Two mite species, Antennoseius pseudospinosus Eidelberg, 1990, a common species in the steppes of southeastern Europe, and Halodarcia incideta Karg, 1969, a polyzonal European hydrophile, are recorded in the taiga zone for the first time. Dorsipes dorsipes Regenfuss, 1968, a specialized parasite of beetles of the genus Carabus Linnaeus, 1758, is new to the fauna of Eastern Europe. An adult mite of the genus Stylochirus G. Canestrini et R. Canestrini, 1882 was found for the first time in a natural hibernating chamber in close contact with an overwintering ground beetle, in particular, a male of S. fimetarius (Müller, 1859) on Carabus granulatus Linnaeus, 1785. The most common mite to occur on ground beetles was Antennoseius bullitus Karg, 1969, which was found on 7 carabid species with the mean occurrence of 41% and comprised 68% of the total mite sample. Joint phoresy of 2–3 mite species was recorded on 12 specimens of ground beetles; in 5 cases the co-occurring mites were Antennoseius bullitus and Stylochirus fimetarius. Three dominant mite species (85% of the total mite sample) were mainly collected off three dominant carabid species (70% of the beetle sample), but individual mite species preferred different hosts.     

Bark and ambrosia beetles (Curculionidae: Scolytinae), their phoretic mites (Acari) and associated Geosmithia species (Ascomycota: Hypocreales) from Virgilia trees in South Africa

Bark and ambrosia beetles are ecologically and economically important phloeophagous insects that often have complex symbiotic relationships with fungi and mites. These systems are greatly understudied in Africa. In the present study we identified bark and ambrosia beetles, their phoretic mites and their main fungal associates from native Virgilia trees in the Cape Floristic Region (CFR) of South Africa. In addition, we tested the ability of mites to feed on the associated fungi. Four species of scolytine beetles were collected from various Virgilia hosts and from across the CFR. All were consistently associated with various Geosmithia species, fungi known from phloeophagous beetles in many parts of the world, but not yet reported as Scolytinae associates in South Africa. Four beetle species, a single mite species and five Geosmithia species were recovered. The beetles, Hapalogenius fuscipennis, Cryphalini sp. 1, and Scolytoplatypus fasciatus were associated with a single species of Elattoma phoretic mite that commonly carried spores of Geosmithia species. Liparthrum sp. 1 did not carry phoretic mites. Similar to European studies, Geosmithia associates of beetles from Virgilia were constant over extended geographic ranges, and species that share the same host plant individual had similar Geosmithia communities. Phoretic mites were unable to feed on their Geosmithia associates, but were observed to feed on bark beetle larvae within tunnels. This study forms the first African-centred base for ongoing global studies on the associations between arthropods and Geosmithia species. It strengthens hypotheses that the association between Scolytinae beetles and dry-spored Geosmithia species may be more ubiquitous than commonly recognised.     

Nematode (Nematoda: Mermithidae) and hairworm (Nematomorpha: Chordodidae) parasites in Early Cretaceous amber

The present report describes a mermithid nematode (Nematoda: Mermithidae) and a gordiid hairworm (Nematomorpha: Chordodidae) from Early Cretaceous Burmese amber dated at 100-110 million years. The mermithid, Cretacimermis protus sp. n., is emerging from a biting midge (Diptera: Ceratopogonidae) while the hairworm, Cretachordodes burmitis, gen. n., sp. n. had already emerged from its host. These rare specimens represent the first fossil mermithid parasite of a ceratopogonid midge and second oldest described nematode and the earliest known and only Mesozoic fossil of the phylum Nematomorpha. A list of previously described fossil mermithids is included.     

Evolutionary aspects of host plant specialisation – a study on bruchids (Coleoptera: Bruchidae)

We have studied the relationship of bruchids and their legume hosts by extensive field sampling throughout Hungary over 17 years and by rearing the beetles from the samples in the laboratory. The value of the system lies in the accuracy of host affiliations. A total of 138 species and subspecies of plants were sampled, representing approximately 87% of the Leguminosae in Hungary. Only 51 legume species (37.0%) harboured bruchids (12 Bruchus spp. and 15 Bruchidius spp). Bruchids occurred in 38.3% of the host plant samples. Thirty-seven plant species congeneric with bruchid host species were unoccupied by bruchids.
The degree of host specificity ranged from monophagy (at least ecological monophagy) to oligophagy. On the basis of presence/absence data we tested the null hypothesis assuming that plant taxa and seed consuming bruchid species form congruent phyletic relations at the species level. We argue that the case for coevolution between the beetles and their hosts is weak. A comparison of the available taxonomic relationships (and presumed phylogenies) best fits a case of sequential evolution, with stronger phylogenetic conservatism in Bruchus species than in Bruchidius species. Bruchid and host plant taxa showed rough congruence only at the tribe level. We suggest that host shifts are best explained by the changes in the bruchids' chemosensory system that determines the females' host selection behaviour.     

Life in harsh environments: carabid and spider trait types and functional diversity on a debris‐covered glacier and along its foreland

1. Patterns of species richness and species assemblage composition of ground‐dwelling arthropods in primary successions along glacier forelands are traditionally described using a taxonomic approach. On the other hand, the functional trait approach could ensure a better characterisation of their colonisation strategies in these types of habitat. 2. The functional trait approach was applied to investigate patterns of functional diversity and life‐history traits of ground beetles and spiders on an alpine debris‐covered glacier and along its forefield in order to describe their colonisation strategies. 3. Ground beetles and spiders were sampled at different successional stages, representing five stages of deglaciation. 4. The results show that the studied glacier hosts ground beetle and spider assemblages that are mainly characterised by the following traits: walking colonisers, ground hunters and small‐sized species. These traits are typical of species living in cold, wet, and gravelly habitats. The diversity of functional traits in spiders increased along the succession, and in both carabids and spiders, life‐history traits follow the ‘addition and persistence model’. Accordingly, there is no turnover but there is an addition of new traits and a variation in their proportion within each species assemblage along the succession. The distribution of ground beetles and spiders along the glacier foreland and on the glacier seems to be driven by dispersal ability and foraging strategy. 5. The proposed functional approach improves knowledge of the adaptive strategies of ground‐dwelling arthropods colonising glacier surfaces and recently deglaciated terrains, which represent landforms quickly changing due to global warming.     

Trait-specific response of ground beetles (Coleoptera: Carabidae) to forest fragmentation in the temperate region in Korea

The objective of this study was to examine the trait-specific response of ground beetles in terms of abundance, species richness, and composition for habitat fragmentation in temperate forests. In addition, we examined how different ecological groups and species of ground beetles responded to environmental variables. During middle May to early November in 2013, ground beetles were sampled using pitfall traps in 27 sites (18 patches and 9 continuous forests) in central Korea. A total of 51 species were identified from 17,845 ground beetles in the 27 study sites. Continuous forests had generally higher abundance and species richness of ground beetles than forest patches. Canonical correspondence analysis for ground beetles was significant, and the proportion of variance explained by environmental variables, such as patch size, elevation, organic matter (C), and soil moisture and pH, was 43.61%. In addition, species composition of ground beetles in continuous forests was grouped distinctively away from those in medium and small-sized patches. In conclusion, both small (1.1–9.6 ha) and medium patches (12.8–51.2 ha) were failed to preserve similar ground beetle biodiversity compared to continuous forests. However, our study revealed that medium-sized forest patches clearly had higher conservation value for forest specialist ground beetles than small-sized forest patches irrespective of forest type.