The carabid beetle species Pterostichus oblongopunctatus is common in different types of forests in Poland and Europe. With respect to this species, some unclarities exist concerning the morphological feature of punctures on the elytra. P. oblongopunctatus has dorsal pits in the third interval of the elytra, the available identification keys, however, provide inconsistent information concerning the puncture in other intervals. During long-term studies at different study sites in Poland, the first author rarely but regularly discovered individuals with unusual dorsal puncture patterns, i.e., pits in the fifth and even in the seventh interval of the elytra. Since such rare patterns might be connected with special habitat characteristics, and thus have a potential as an indicator, the aim of the study was to test if they are connected with specific subpopulations (interaction groups), if they are related to the sex or size of the beetles, and if they are related to specific habitat conditions.
The host-parasite associations between ground beetles (Coleoptera: Carabidae) and hairworms (Nematomorpha: Gordiida) collected from the arctic (an understudied and ecologically important region) is described. Carabids and their parasites were collected from 12 sites spanning the 3 northernmost ecoclimatic zones of Canada (north boreal, subarctic and high arctic) using standardized methods. The beetles and hairworms were identified using traditional morphological approaches. Seven beetle species are recorded as hosts: Amara alpina, Pterostichus caribou, P. brevicornis, P. tareumiut, P. haematopus, Patrobus septentrionis, and Notiophilus borealis. All represent new host records (increasing the known North American host list from 14 to 21), and this is the first record of hairworm infection in the genus Notiophilus. Beetles from Banks Island, Northwest Territory, were infected in high numbers (11-19% per sampling period) and were used as an ecological case study. There was no significant relationship between infection status and host species, body size or sex. Beetles collected in yellow pan traps and in wet habitats were more likely to be infected, likely due to water-seeking behavior induced by the parasites. Morphological examinations indicate that the hairworms collected from all locations represent a single, new species of Gordionus, making it only the sixth hairworm species and the third species of that genus found in Canada. Hosts are unknown for all other Canadian (and 1 Alaskan) Gordionus species.
Despite the important roles ground beetles (Coleoptera: Carabidae) play in ecosystems, the highly valued ecosystem services they provide, and ample descriptive documentation of their phenology, the relative impact of various environmental factors on carabid phenology is not well studied. Using the long-term pitfall trap capture data from 12 terrestrial Environmental Change Network (ECN) sites from the UK, we examined how changing climate influenced the phenology of common carabids, and the role particular climate components had on phenological parameters. Of the 28 species included in the analyses, 19 showed earlier start of their activity. This advance was particularly pronounced in the spring, supporting the view that early phenophases have a greater tendency to change and these changes are more directly controlled by temperature than later ones. Autumn activity extended only a few cases, suggesting a photoperiod-driven start of hibernation. No association was found between life-history traits and the ability of species to change their phenology. Air temperatures between April and June were the most important factors determining the start of activity of each species, whilst late season precipitation hastened the cessation of activity. The balance between the advantages and disadvantages of changing phenology on various levels is likely to depend on the species and even on local environmental criteria. The substantially changing phenology of Carabidae may influence their function in ecosystems and the ecosystem services they provide.
The life cycle of Neotropical ground beetle, Abaris basistriata (Coleoptera: Carabidae) reared on different substrates
- Brazilian journal of biology = Revista brasleira de biologia
- Published almost 3 years ago
Carabids are recognized worldwide as biological control agents of agricultural pests. The objective was to compare the life cycle of Abaris basistriata Chaudoir (Coleoptera: Carabidae) on three substrates: soil, fine vermiculite, or paper napkins. The biological cycle of A. basistriata presented different durations in soil and paper. The viability of eggs and larvae survival of the first and second instars were similar on all three substrates, while the third instar and pupa in the soil presented higher survival when compared with vermiculite and paper. The soil substrate was more favorable for the longevity of the carabid beetle. Abaris basistriata showed a shorter pre-oviposition period and a higher oviposition and post-oviposition period in the soil. Fecundity and fertility were higher when A. basistriata was reared on soil. The soil was most favorable substrate for rearing of A. basistriata in the laboratory. This information may make this species useful for the biological control.
Male and larval female of the parasitic mite Eutarsopolipus abdominis Regenfuss, 1968 (Acari: Prostigmata: Podapolipidae) belonging to the myzus species group, are described and illustrated for the first time based on the materials recovered from under elytra of Agonum sp. (Coleoptera: Carabidae) from Mazandaran Province, Northern Iran. A redescription of the adult female is also provided. It is the first record of this species from Asia and fourth representative of parasitic mites of myzus group found from Iran. Furthermore, this finding revealed the first record of the association between tribe Platynini (Coleoptera: Carabidae: Harpalinae) and mites of myzus species group, and one of the highest level of polyxeny among mites of the genus Eutarsopolipus.
Effects of passive restoration of mountain rivers on the organisms inhabiting exposed riverine sediments are considerably less understood than those concerning aquatic biota. Thus, the effects of a recovery of the Raba River after abandonment of maintenance of its channelization scheme on ground beetle (Coleoptera: Carabidae) communities were investigated by comparing 6 unmanaged cross-sections and 6 cross-sections from adjacent channelized reaches. In each cross-section, ground beetles were collected from 12 sampling sites in spring, summer, and autumn, and 8 habitat parameters characterizing the cross-sections and sampling sites were determined. Within a few years after abandonment of the Raba River channelization scheme, the width of this gravel-bed river increased up to three times and its multi-thread pattern became re-established. Consequently, unmanaged river cross-sections had significantly larger channel width and more low-flow channels and eroding cutbanks than channelized cross-sections. Moreover, sampling sites in the unmanaged cross-sections were typified by significantly steeper average surface slope and larger average distance from low-flow channels than the sites in channelized cross-sections. In total, 3992 individuals from 78 taxa were collected during the study. The ground beetle assemblages were significantly more abundant and richer in species in the unmanaged than in the channelized cross-sections but no significant differences in carabid diversity indices between the two cross-section types were recorded. Redundancy Analysis indicated active river zone width as the only variable explaining differences in abundance and species richness among the cross-sections. Multiple regression analysis indicated species diversity to predominantly depend on the degree of plant cover and substrate grain size. The study showed that increased availability of exposed sediments in the widened river reaches allowed ground beetles to increase their abundance and species richness within a few years after the onset of river restoration, but more time may be needed for development of more diverse carabid communities.
Although ecological succession is one of the principal focuses of recent restoration ecology research, it is still unclear which factors drive this process and positively influence species richness and functional diversity. In this study we sought to elucidate how species traits and functional diversity change during forest succession, and to identify important factors that determine the species in the observed assemblages. We analyzed species richness and functional diversity of ground beetle assemblages in relation to succession on post-industrial localities after habitat deterioration caused by spoil deposition. We selected ground beetles as they are known to be sensitive to landscape changes (with a large range of responses), and their taxonomy and ecology are generally well-known. Ground beetles were sampled on the spoil heaps during the last 30 years when spontaneous succession occurred. To calculate functional diversity, we used traits related to habitat and trophic niche, i.e. food specialization, wing morphology, trophic level, and bio-indication value. Ground beetle species were found to be distributed non-randomly in the assemblages in the late phase of succession. Ordination analyses revealed that the ground beetle assemblage was significantly associated with the proportion of forested area. Environmental heterogeneity generated assemblages that contained over-dispersed species traits. Our findings indicated that environmental conditions at late successional stages supported less mobile carnivorous species. Overall, we conclude that the decline in species richness and functional diversity in the middle of the studied succession gradient indicated that the assemblages of open habitats had been replaced by species typical of forest ecosystems.
Olfactory ability is an element of fitness in many animals, guiding choices among alternatives such as mating partners or food. Ground beetles (Coleoptera; Carabidae), exhibit preferences for prey, and some species are well-known weed seed predators. We used olfactometer-based bioassays to determine if olfactory stimuli are associated with detection of Brassica napus L., Sinapis arvensis L., and Thlaspi arvense L. seeds by ground beetles characteristic of agroecosystems, and whether behavioural responses to seed odors depended on seed physiological state (imbibed or unimbibed). Imbibed B.napus seeds were preferred over other weed species by two of the three carabid species tested. Only A. littoralis responded significantly to unimbibed seeds of B. napus. Sensitivity to olfactory cues appeared to be highly specific as all carabid species discriminated between the olfactory cues of imbibed brassicaceous weed seeds, but did not discriminate between weed seeds that were unimbibed. Overall, our data suggest that depending on seed physiological state, odours can play an important role in the ability of carabids to find and recognize seeds of particular weed species.
Metal toxicokinetics and metal-driven damage to the gut of the ground beetle Pterostichus oblongopunctatus
- Environmental science and pollution research international
- Published about 4 years ago
Toxicokinetics makes up the background for predicting concentrations of chemicals in organisms and, thus, ecological risk assessment. However, physiological and toxicological mechanisms behind toxicokinetics of particular chemicals are purely understood. The commonly used one-compartment model has been challenged recently, showing that in the case of metals it does not describe the pattern observed in terrestrial invertebrates exposed to highly contaminated food. We hypothesised that the main mechanism shaping toxicokinetics of metals in invertebrates at high exposure concentrations in food is the cellular damage to the gut epithelial cells. Gut damage should result in decreased metal assimilation rate, while shedding the dead cells - in increased elimination rate. We performed a typical toxicokinetic experiment, feeding the ground beetles Pterostichus oblongopunctatus food contaminated with Cd, Ni or Zn at 40 mM kg(-1) for 28 days, followed by a depuration period of 14 days on uncontaminated food. The male beetles were sampled throughout the experiment for body metal concentrations and histopathological examinations of the midgut. All metals exhibited a complex pattern of internal concentrations over time, with an initial rapid increase followed by a decrease and fluctuating concentrations during further metal exposure. Histopathological studies showed massive damage to the midgut epithelium, with marked differences between the metals. Cd appeared the most toxic and caused immediate midgut cell degeneration. The effects of Ni were more gradual and pronounced after at least 1 week of exposure. Zn also caused extensive degeneration in the gut epithelium but its effects were the weakest among the studied metals.
Commercial cucurbit production typically involves agriculturally intensive practices, with fields prepared using conventional tillage, plasticulture, and chemically based pest management. Conservation-based management options are limited. In this study, we consider two alternative strategies, strip tillage and the use of row covers. We compare their impact on the beneficial carabid beetle (Coleoptera: Carabidae) community in melons and squash, following conventional or organic systems, over two years. Multivariate analysis demonstrated that soil management system (strip tillage versus plasticulture) was the primary variable influencing carabid distribution; row cover was a less important factor. The response to soil management was species dependent. Some dominant species, such as Harpalus pensylvanicus DeGeer, demonstrated no preference for a particular soil treatment. For others, including the tiger beetle, Cicindela punctulata Olivier, and a slug predator, Chlaenius tricolor Dejean, activity-density was higher in strip-tillage production systems. Our analysis suggested that strip-tillage production systems support a richer, more diverse carabid community. These results demonstrate that even within intensive annual horticultural systems, production practices can play a critical role in shaping the beneficial arthropod community, potentially encouraging or limiting ecosystem services.