Fig 1 - uploaded by Vincent Bretagnolle
Content may be subject to copyright.
Mean seed intake of Viola arvensis consumed by 28 carabid beetle species (±1 SE), with the number of individuals tested on the bottom of the histogram for each species. Species are grouped according to their tribe, within tribe they are classified from the lowest consumer to the highest.
Source publication
Seedbank control has been the cornerstone of agricultural management practices. Regulating weeds by using their predators, as a weed control strategy, may be a prerequisite of decreasing herbicide use, and has thus attracted much research investigating the possible contribution of both vertebrates and invertebrates as weed seed predators. Carabid b...
Context in source publication
Context 1
... were obvious variations in the consumption shown by different beetle species for the seed ( fig. 1). Ten of the 12 species tested in Harpalini tribes seemed to actively seek and eat Viola seeds (five seeds or more). For species of the Pterostichini tribe, individuals ate on average between 0 and 3.28 seeds. Table 1. Feeding preferences of 28 carabid beetle species tested during our experimentation based on literature survey ...
Similar publications
Seed bank control is the mainspring of agricultural management practices. Using weeds seeds natural predators as a weed control strategy can be a valuable alternative to herbicide use. Among natural predators, ground beetles (Coleoptera, family Carabidae) have been claimed to be one of the most important invertebrate seeds predators in agroecosyste...
Seeds of many species of plants may survive for a long time in the soil and germinate when brought to the surface, but whether they are subsequently eaten by seed predators is unknown. We examined the preferences of three species of carabids (Coleoptera: Carabidae) for 25 species of seeds and determined the difference in palatability between freshl...
Citations
... Ground beetles (Coleoptera: Carabidae) are an ideal group for characterizing relationships between invertebrate and tree communities as they are a well-described, species-rich family that fulfill a variety of functional roles in forests (Koivula, 2011;Bousquet, 2012;Lövei and Sunderland, 1996;Kotze et al., 2011) Trophically, ground beetles include carnivores, granivores, fungivores, and omnivores (Lövei and Sunderland, 1996;Bohan et al., 2011;Kotze et al., 2011;Deroulers and Bretagnolle, 2019), which result in ground beetles contributing to a variety of ecosystem functions. Forests often host more specialized populations of ground beetles than other habitats (Halme and Niemelä, 1993;Butterfield et al., 1995), making these communities particularly susceptible to changes in forest composition. ...
Purpose: Soil invertebrates are abundant and diverse members of forest ecosystems, contributing in large parts to
ecosystem functioning. Understanding drivers of soil invertebrate diversity, density, and community composition
is critical to inform management practices as forests face rapid changes in land use and climate. Tree community
metrics may help predict invertebrate communities due to their large role in shaping microhabitat and soil
conditions. Ground beetles are a large family of soil-dwelling invertebrates comprised of multiple functional
groups ideal for tying tree communities to invertebrate communities broadly. Methods Here, we evaluated the
effects of tree diversity, density, and functional groups on ground beetle (Carabidae) diversity, density, and
community composition in four eastern US temperate forest sites in the National Ecological Observatory
Network. Results We found little evidence to support our hypothesis that higher tree diversity and density would,
respectively, lead to higher diversity and density ground beetle communities. Instead, evergreen tree abundance
strongly shaped ground beetle density and community composition. Specifically, evergreen stands contained a
lower density of ground beetles than deciduous stands. Similarly, the relative abundance of predatory ground
beetles increased as the relative abundance of evergreen trees increased. Conclusions Our results show that the
resource environments created by trees with varying leaf habits are a dominant force driving ground beetle
community diversity and density patterns and suggest that future research exploring mechanisms driving this
pattern could improve our understanding of plant-soil interactions.
... We also observed that the beneficial effects of crop diversity on weed control were mediated by a strong top-down control of weed seeds by their natural enemies (38,39). Suitable candidates for weed seed control in arable crops are carabid beetles (38), which feed on many weed seed species (40), are known to contribute to seed bank regulation (41) and respond positively to crop heterogeneity (42,43). Although we cannot rule out that crop rotation (44) may have contributed to the crop diversity effect detected in our analyses, we are confident that weed seed control delivered by natural enemies contributed to the observed pattern given the correlation found between seed predation rate and weed abundance in this study as in others studies (41,45). ...
Increasing landscape heterogeneity has been suggested to be an important strategy to strengthen natural pest control in crops, especially through enhancing the amount of seminatural habitats. Increasing crop diversity is also a promising strategy to complement or replace seminatural habitat when seminatural habitat is scarce. However, their relative or possibly interactive effects on pest and weed infestation remain poorly investigated, and the role of different types of seminatural habitats has been understudied. Using an extensive sampling effort in 974 arable fields across 7 y, we evaluated the separate and interactive effects of crop diversity (seven arable crop types) and the amount of four types of seminatural habitats (meadows, hay, forests, and hedgerows) in the landscape on pest and weed control. Meadows and crop diversity, respectively, supported insect pest and weed control services in agricultural landscapes through a complementarity effect. Crop diversity increased weed seed predation rate (by 16%) and reduced weed infestation (by 6%), whereas long-term grasslands (to a much higher degree than hay or woody habitats) increased insect pest predation rates (by 23%) and reduced pest infestation (by 19%) in most arable crops. Our results demonstrate that diversification of the agricultural landscape requires long-term grasslands as well as improved crop diversity to ensure the delivery of efficient pest and weed control services.
... Many species of ground beetles, as universal predators with a wide food spectrum, can act as an essential component of biological regulation (Symondson et al. 2002;Stiling and Cornelissen 2005). And in agricultural landscapes, they play a very significant role in reducing the number of pests (Koval andGuseva 2008, Halimov 2020) and weeds (Talarico et al. 2016, Deroulers andBretagnolle 2019). ...
Citation: Khalimov F (2023) Composition and structure of the fauna of ground beetles (Coleoptera, Carabidae) of the Zerafshan Range. Acta Biologica Sibirica 9: 113-125. https://doi.org/10.5281/zenodo.7725474 Abstract The article presents the results of studying the fauna of ground beetles in the western part of the Zer-afshan Range (Uzbekistan). The Carabidae list includes 81 species from 41 genera, 18 tribes and nine subfamilies. The ecological diversity of the ground beetle fauna is analyzed on three parts of the ridge. The greatest diversity of Carabidae is noted in the Karatepo Mountains (74 species), and the smallest in the Zirabulak-Ziyadin Mountains (54 species). The fauna of the ground beetles of the Chakalikalyan and Karatepa Mountains are closer to each other (Jaccard index-0.79, Chekanovsky-Sørensen coefficient -0.89). The lowest value of the similarity coefficients was noted between the Chakalikalyan and Zirabulak-Ziadin Mountains (0.64; 0.78). The most numerous are Anchomenus dorsalis (10.46%), Calathus ambiguus (8.23%), Amara aenea (7.48%) and Harpalus rufipes (6.03%).
... Identifying and choosing the optimum exposure period and time for estimating weed seed predation levels was challenging. Most of the relevant previous studies assessed seed predation during long-term exposure periods, ranging from a couple of weeks to several months [51][52][53]. In our study, however, to achieve accurate estimates of seed predation levels, data on seed predation from day 0 to day 2 (48 h exposure period) were used, based on the low number of remaining seeds left on the final days of the field exposure. ...
Weeds are one group of pests that significantly reduce crop yields and qualities, while herbicide use poses a risk to human health and environment. Weed seed predation has been identified as a potential biocontrol approach offering sustainable weed management. It causes substantial seed losses on weed species in crop fields, and thus may result in a reduction in herbicide use. This study aimed to investigate the relevant seed predation patterns on important weed species, Galium aparine L., Papaver rhoeas L., and Apera spica-venti L., in a winter wheat field and the adjacent semi-natural habitat (SNH) near Gödöllő, Hungary, assuming that weed seeds are likely to be predated, but predation levels may differ by weed species and habitat type. Sampling rounds were performed twice, in 2019 and 2021, before crop harvest, by placing a total of 240 seed cards (120 cards/round) on the soil surface inside both crop field, and in the adjacent SNH. Seed predation was assessed on each card every 24 h, for 5 days in 2019 and 6 days in 2021. The results revealed high intensity (100%) of seed predation on the evaluated weed species, during the exposure periods in both years and habitat types, although weed seeds were significantly consumed (p < 0.001) in 2019 as opposed to 2021. Whereas, seed consumption levels were not significantly different (p = 0.802) among habitat types, and between habitats and years (p = 0.842). The optimum period for measuring weed seed predation was found to be after 48 h of field exposure. Our findings showed that seed predation reduced the number of exposed weed seeds on the soil surface, which may decrease the weed seed banks, and the number of weed seedlings the next cropping season.
... Often, the shape of mandibles is linked to different foraging strategies. In carabid beetles, the wider and shorter mandibles are associated with phytophagous species (Deroulers & Bretagnolle, 2019). In dung beetles (Bai et al., 2015), in checkered beetles (Vega & Hofstetter, 2015) and grasshoppers Kang et al., 1999), morphological differences in mandible shape are linked to the quality (shape, texture or toughness) of the food resource. ...
The extinction of species is a non‐random process, and understanding why some species are more likely to go extinct than others is critical for conservation efforts. Functional trait‐based approaches offer a promising tool to achieve this goal. In forests, deadwood‐dependent (saproxylic) beetles comprise a major part of threatened species, but analyses of their extinction risk have been hindered by the availability of suitable morphological traits.
To better understand the mechanisms underlying extinction in insects, we investigated the relationships between morphological features and the extinction risk of saproxylic beetles. Specifically, we hypothesised that species darker in colour, with a larger and rounder body, a lower mobility, lower sensory perception and more robust mandibles are at higher risk.
We first developed a protocol for morphological trait measurements and present a database of 37 traits for 1,157 European saproxylic beetle species. Based on 13 selected, independent traits characterising aspects of colour, body shape, locomotion, sensory perception and foraging, we used a proportional‐odds multiple linear mixed‐effects model to model the German Red List categories of 744 species as an ordinal index of extinction risk.
Six out of 13 traits correlated significantly with extinction risk. Larger species as well as species with a broad and round body had a higher extinction risk than small, slim and flattened species. Species with short wings had a higher extinction risk than those with long wings. On the contrary, extinction risk increased with decreasing wing load and with higher mandibular aspect ratio (shorter and more robust mandibles).
Our study provides new insights into how morphological traits, beyond the widely used body size, determine the extinction risk of saproxylic beetles. Moreover, our approach shows that the morphological characteristics of beetles can be comprehensively represented by a selection of 13 traits. We recommend them as a starting point for functional analyses in the rapidly growing field of ecological and conservation studies of deadwood.
... In this study, we conducted a multiple-choice test to determine the preference of the three carabid species: Pterostichus melanarius, Poecilus cupreus and Anchomenus dorsalis. Although the representatives of the genera Pterostichus, Poecilus and Anchomenus are commonly regarded as predominantly carnivorous species, they have been frequently observed to consume seeds (Goldschmidt & Toft 1997, Honek et al. 2003, Hurst & Doberski 2003, Deroulers & Bretagnolle 2019. The presence of plant DNA in carabid regurgitates of P. melanarius and P. rufipes was found to be substantial (>70% of individuals) and independent of carabid species, sex, region and the time of sampling (Frei et al. 2019). ...
Seed predators are an integral part of agroecosystems, where they can reduce the populations of weeds. The preference of predators for seeds and the observed predation rate may be affected by the properties of seeds (e.g. taxonomy, chemical composition, physical defence). In this work, we focused on seed consumption of Taraxacum officinale Web. and Stellaria media (L.) Vill., from France and the Czech Republic, by three species of ground beetle that are seed predators (Coleoptera: Carabidae): Poecilus cupreus (Linnaeus), Pterostichus melanarius (Illiger) and Anchomenus dorsalis (Pontoppidan). The seed species were offered in arenas, simultaneously, under three different experimental manipulations of moisture and seed coat conditions: dry and intact, water-imbibed and intact, and water-imbibed with a damaged seed coat. Seed consumption was checked after 0.5, 1, 2, 24, and 48 hours of exposure. Anchomenus dorsalis largely refused to feed on seeds. Taraxacum officinale seeds with damaged coats were most preferred by the remaining two species of carabids. The consumption by P. cupreus of T. officinale seeds with damaged coats increased from 0.18 % after 0.5 hours to 83.83 % after 48 hours, and by P. melanarius from 13.76 % after 0.5 hours to 76.77 % after 48 hours. Seeds of S. media were consumed less. There was a significant difference in consumption rates due to the country of origin of the seeds, but there were no differences between the carabid sexes. That carabids preferred water-imbibed and damaged seeds may suggest an involvement of olfactory clues in the seed selection process, and/or shorter seed-handling times.
... A shorter period of test (24 h vs 48 h) may also explain the lower mortality rate measured in the second protocol of replicated test. Our general housing conditions were tested on a total of 28 different ground beetle species (Deroulers and Bretagnolle 2018) using the same conditions (box size, food items, temperature and humidity), and all species accustomed to these conditions despite supposed large diet differences. For future research, this protocol type will allow to replicate tests, as an example, to compare interspecific consumption between weed seed by ground beetles, or to measure and to compare consumption with the same individual of ground beetle species with different seed densities. ...
Seed bank control is the mainspring of agricultural management practices. Using weeds seeds natural predators as a weed control strategy can be a valuable alternative to herbicide use. Among natural predators, ground beetles (Coleoptera, family Carabidae) have been claimed to be one of the most important invertebrate seeds predators in agroecosystems. However, information on the trophic relationship among these two large communities is fragmentary. Laboratory experiments have been conducted using a wide variety of protocols on a few ground beetle and weed seed species. To better characterize trophic relationship among these communities, a standardized and simple protocol is required. We propose a protocol to quantitatively assess weed seed consumption by ground beetles. Importantly, we explore parameters that should be optimized and fixed since they are not targeted, such as fasting time, test duration and substrate type. We also investigate whether, and under which conditions, tests may be replicated with the same individuals. Tests were carried out on five ground beetle species and eight weed seed species, though in the majority of tests Viola arvensis was used. Using climatic chambers, parameters such as temperature, humidity and photoperiod were fixed at 25 °C, 70% and 17-h/7-h day/night, respectively. Fasting time prior testing and test duration were fixed to 3 days and 24 h, respectively, to avoid mortality of ground beetle species that do not rely on seeds as their main food. Also, a recovery period of 24 h between successive tests is required when multiple tests are conducted on the same individuals. Among the substrate tested, we recommend to use sand as it appeared the most convenient substrate to conduct a large amount of replicated experiments.
... After spatial aggregation of carabids, we detected effects of two other medium size species, P. cupreus and P. rufipes, which are spring and autumn breeder species respectively (Cole et al., 2002;Homburg et al., 2014;Pey et al., 2014), and are the dominant species of the genera Poecilus and Pseudoophonus, respectively, in our data. The importance of these key genera corroborates the findings of previous studies that have shown that genera from the tribe Harpalini, such as Harpalus or Pseudoophonus, consumed significant quantities of V. arvensis seeds in laboratory cafeteria tests (Honek et al., 2007;Petit et al., 2014;Deroulers and Bretagnolle, 2019). Interestingly, P. cupreus does not show a preference for V. arvensis seeds in cafeteria tests, eating some 0.40 seeds / day in comparison to 4.65 and 15.37 seeds / day for H. affinis and P. rufipes, respectively . ...
Understanding the contribution of naturally occurring assemblages of carabids to weed seed predation is necessary for the implementation of conservation biological control. Identifying key species, and their combinations, that drive high seed mortality is important to promote natural biocontrol of weeds and appropriate field management for conserving this ecosystem service.
Using a regression tree algorithm and data from 111 arable fields, we tested the hypothesis that there are key carabid species or genera for seed predation of Viola arvensis. This method was applied to the dataset at taxonomic (species, genus) and spatial scales (plot, transect and intermediate) in order to compare the outcome of regression trees, their predictive value and to identify the resolution(s) at which relationships between carabid assemblages and seed depletion should be addressed.
Predation of V. arvensis seed can be explained by the presence of three key carabid genera: Harpalus, Poecilus and Pseudoophonus. The analysis indicated the importance of co-occurrence between certain species of these genera for the delivery of high seed predation rates. These beneficial associations may indicate functional complementarity between species for predation. Potential intraguild carnivores, such as Carabus auratus, appear responsible for a decrease in predation when they are present in certain carabid assemblages. Our results show that the regression tree methodology is robust and stable. Grouping species into genera explained a slightly greater percentage of the variation in the V. arvensis predation rate than species alone, as well as spatial aggregation of records, that also led to increased detection of key species.
Our approach suggests that for the conservation biological control of V. arvensis it is necessary to promote the activity density of Harpalus, Poecilus and Pseudoophonus. The statistical modelling approach we develop could be a useful method for selecting field management that supports the key species identified and enhances predation.
Keywords: weed seed predation; carabid beetle; complementarity; community; regression tree.
... opportunistic omnivores) to predators feeding both on plant and animal food (i.e. obligate omnivores) (Hengeveld 1979;Deroulers & Bretagnolle 2018). Granivore and obligate omnivore species coexist within carabid communities of arable fields, but the relative contribution of species exhibiting one diet or the other to weed suppression has not yet been resolved. ...
The prediction of pest regulation by multi-predator communities often remains challenging because of variable and opposite effects of niche complementarity and predator interference. Carabid communities are regulating weeds in arable fields and include a mix of species ranging from granivores to predators that are obligate omnivores. It is not clear from field studies whether granivore and obligate omnivore species either contribute equally or are complementary in the process of weed suppression, and little is known about the impact of potential predator interference within carabid communities on weed suppression. We compared the weed seed foraging strategy of the granivore Harpalus affinis and the obligate omnivore Poecilus cupreus. Using no-choice test experiments, we compared their activity and seed acceptance for four weed species through a scoring of the proportion of tested individuals consuming weeds, their latency before the consumption of the first seed and the total number of seeds consumed. We then evaluated their seed acceptance for dandelion seed Taraxacum officinale under predator interference by using chemical cues of carabids and tested the impact of three treatments, namely cues of intraspecific competition, interspecific competition and intraguild predation. We found that the obligate omnivore P. cupreus was highly active, had a low latency before consuming its first seed but had an interest in only two of the four weed species. P. cupreus seed acceptance remained unchanged in the presence of predator cues. By contrast, H. affinis was slow to start its seed consumption, accepted equally seeds of the four weed species and significantly increased its seed consumption in the presence of cues mimicking intraguild predation. These findings indicate that the two species differ in their foraging strategies, and as such, could have different contributions to weed seed suppression. This novel result calls for further studies documenting the foraging strategy of carabid species that thrive in arable fields as this could significantly improve our understanding of the delivery of weed seed regulation.
Agricultural intensification has altered the provision of natural bioregulation. We assessed the effects of five different crops under non-inversion tillage on the temporal dynamics of carabid assemblages. We evaluated how the taxonomic diversity, the composition, and the diet-based functional structure of communities varied over the spring period.
Carabid assemblages were monitored over 4 years (from 2009 to 2012), in a total of 67 fields (each field followed one year) cropped with either winter oilseed rape, winter wheat, sugar beet, spring barley, or spring pea. We assigned a relative diet profile to each species accounting for more than 0.5 % of the total mean abundance-activity: granivorous, phytophagous, and zoophagous.
The seasonal changes in species richness, abundance-activity, and evenness had the same dynamic in all crops. Despite differences in species identities between crops, the zoophagous and phytophagous diet profiles showed similar temporal dynamics in all crop types, suggesting a high functional equivalence among species present in cultivated fields. Zoophagous species were progressively replaced by primarily phytophagous species in all crops, while the increase in granivorous species was only observed in oilseed rape.
Our results suggest that potential bioregulation do not significantly differ among crop types but vary along the spring season.
Highlights
We monitored carabid communities in five crop types under non-inversion tillage
We observed similar seasonal increases in carabid abundance-activity and species richness in all crops during the spring period
We observed similar trends in temporal changes in carnivorous and phytophagous diet profiles in all crops
With seasonal changes, zoophagous species are progressively replaced by more phytophagous species
Crop type is not the main factor driving temporal changes in diet-based structure of carabid assemblages
