Spatial and temporal patterns of carabid activity-density in cereals do not explain levels of predation on weed seeds

2007 ◽  
Vol 98 (2) ◽  
pp. 169-181 ◽  
Author(s):  
P. Saska ◽  
W. van der Werf ◽  
E. de Vries ◽  
P.R. Westerman
Keyword(s):  
Temporal Variation ◽  
Seed Predation ◽  
Physiological State ◽  
Weed Suppression ◽  
Carabid Beetles ◽  
Spatial And Temporal Variation ◽  
Pitfall Traps ◽  
Spatial And Temporal Patterns ◽  
Background Density ◽  
Activity Density

AbstractSeed predation is an important component of seed mortality of weeds in agro-ecosystems, but the agronomic use and management of this natural weed suppression is hampered by a lack of insight in the underlying ecological processes. In this paper, we investigate whether and how spatial and temporal variation in activity-density of granivorous ground beetles (Coleoptera: Carabidae) results in a corresponding pattern of seed predation. Activity-density of carabids was measured by using pitfall traps in two organic winter wheat fields from March to July 2004. Predation of seeds (Capsella bursa-pastoris,Lamium amplexicaule,Poa annuaandStellaria media) was assessed using seed cards at the same sites and times. As measured by pitfall traps, carabids were the dominant group of insects that had access to the seed cards. In the field, predation of the four different species of seed was in the order:C. bursa-pastoris>P. annua>S. media>L. amplexicaule; and this order of preference was confirmed in the laboratory using the dominant species of carabid. On average, seed predation was higher in the field interior compared to the edge, whereas catches of carabids were highest near the edge. Weeks with elevated seed predation did not concur with high activity-density of carabids. Thus, patterns of spatial and temporal variation in seed predation were not matched by similar patterns in the abundance of granivorous carabid beetles. The lack of correspondence is ascribed to effects of confounding factors, such as weather, the background density of seeds, the composition of the carabid community, and the phenology and physiological state of the beetles. Our results show that differences in seed loss among weed species may be predicted from laboratory trials on preference. However, predator activity-density, as measured in pitfall traps, is an insufficient predictor of seed predation over time and space within a field.

Oviposition pattern and within-season spatial and temporal variation of pre-dispersal seed predation in a population of Mimosa bimucronata trees

2011 ◽  
Vol 5 (3) ◽  
pp. 209-217 ◽  
Author(s):  
Marcelo N. Rossi ◽  
Ligia M. da Silva Rodrigues ◽  
Marcos N. Ishino ◽  
Débora Kestring
Keyword(s):  
Temporal Variation ◽  
Seed Predation ◽  
Spatial And Temporal Variation

Diversity and seasonal density of carabid beetles (Coleoptera: Carabidae) in relation to the soybean aphid in soybean crop in Québec, Canada

2012 ◽  
Vol 144 (4) ◽  
pp. 542-554 ◽  
Author(s):  
Annabelle Firlej ◽  
Annie-Ève Gagnon ◽  
Simon Laurin-Lemay ◽  
Jacques Brodeur
Keyword(s):  
Multivariate Analyses ◽  
Sampling Period ◽  
Soybean Aphid ◽  
Carabid Beetles ◽  
Pitfall Traps ◽  
Activity Density ◽  
Pterostichus Melanarius ◽  
Trap Catches ◽  
Field Location ◽  
Aphid Populations

AbstractWe studied the diversity and summer seasonal activity-density of Carabidae associated with soybean fields infested by the soybean aphid (Aphis glycinesMatsumura; Hemiptera: Aphididae) in Québec, Canada. Carabid beetles were sampled in six to seven fields from June to September 2004 and 2005 using pitfall traps. A total of 33 species from 15 genera were identified, with the exoticPterostichus melanarius(Illiger) (Coleoptera: Carabidae), representing 75.8% and 84.5% of all individuals trapped in 2004 and 2005, respectively. Large variations in species richness and diversity indexes were observed between fields within and between years. Multivariate analyses showed that carabid activity-density varied as a function of field location and sampling period, with individuals belonging to species overwintering as adults being more abundant early in the growing season. There was no relationship between carabid trap catches andA. glycinesdensity, suggesting that carabid beetles do not respond numerically to soybean aphid populations at the spatial scale studied.

Factors affecting spatial and temporal patterns in perfluoroalkyl acid (PFAA) concentrations in migratory aquatic species: a case study of an exploited crustacean

2019 ◽  
Vol 21 (11) ◽  
pp. 1946-1956 ◽  
Author(s):  
Matthew D. Taylor
Keyword(s):  
Temporal Variation ◽  
Temporal Patterns ◽  
Spatial And Temporal Variation ◽  
Aquatic Species ◽  
Spatial And Temporal Patterns ◽  
Physiological Factors ◽  
Factors Affecting ◽  
Free Ranging ◽  
Perfluoroalkyl Acid

Free-ranging prawns showed substantial spatial and temporal variation in PFOS concentrations, most likely driven by behavioural and physiological factors.

scholarly journals Aggregation of ground beetles (Carabidae, Coleoptera) on winter rape seeds dispersed on the ground

2001 ◽  
Vol 37 (No. 3) ◽  
pp. 97-102 ◽  
Author(s):  
A. Honěk ◽  
Z. Martinková
Keyword(s):  
Indirect Method ◽  
Ground Beetles ◽  
The Other ◽  
Carabid Beetles ◽  
Pitfall Traps ◽  
Winter Rape ◽  
Activity Density ◽  
Seed Eating ◽  
Total Seed ◽  
And Control

The preference of adult polyphagous ground beetles (Carabidae, Coleoptera) for winter rape seeds was investigated using an indirect method. Rape seeds were scattered around pitfall traps. The catches of carabid beetles in these traps and control traps without seeds were compared. The traps were exposed in two stands of winter wheat. In the wheat stand where overall carabid activity density was high, the presence of rape seeds significantly increased the catches of total seed-eating carabids, and of the two species Pseudoophonus rufipes and Calathus fuscipes. The effect was not significant in the other wheat stand where activity density was low. The aggregation of carabids at places with winter rape seeds indicated the importance of carabid predation on seeds scattered on the ground.

scholarly journals The resilience of weed seedbank regulation by carabid beetles, at continental scales, to alternative prey

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Benjamin Carbonne ◽  
Sandrine Petit ◽  
Veronika Neidel ◽  
Hana Foffova ◽  
Eirini Daouti ◽  
...  
Keyword(s):  
Seed Predation ◽  
Carabid Beetles ◽  
Generalist Predators ◽  
Alternative Prey ◽  
Weed Seed ◽  
Agricultural Ecosystem ◽  
Continental Scale ◽  
Activity Density ◽  
Soil Seedbank ◽  
Cereal Fields

Abstract Carabids are generalist predators that contribute to the agricultural ecosystem service of seedbank regulation via weed seed predation. To facilitate adoption of this ecosystem services by farmers, knowledge of weed seed predation and the resilience of seedbank regulation with co-varying availability of alternative prey is crucial. Using assessments of the seedbank and predation on seed cards in 57 cereal fields across Europe, we demonstrate a regulatory effect on the soil seedbank, at a continental scale, by groups formed of omnivore, seed-eating (granivore + omnivore) and all species of carabids just prior to the crop-harvest. Regulation was associated with a positive relationship between the activity-density of carabids and seed predation, as measured on seed cards. We found that per capita seed consumption on the cards co-varied negatively with the biomass of alternative prey, i.e. Aphididae, Collembola and total alternative prey biomass. Our results underline the importance of weed seedbank regulation by carabids, across geographically significant scales, and indicate that the effectiveness of this biocontrol may depend on the availability of alternative prey that disrupt the weed seed predation.

Brassicaceous Weed Seed Predation by Ground Beetles (Coleoptera: Carabidae)

Weed Science ◽  
2016 ◽  
Vol 64 (2) ◽  
pp. 294-302 ◽  
Author(s):  
Sharavari S. Kulkarni ◽  
Lloyd M. Dosdall ◽  
John R. Spence ◽  
Christian J. Willenborg
Keyword(s):  
Seed Predation ◽  
Weed Management ◽  
Physiological State ◽  
Seed Removal ◽  
Weed Seed ◽  
Weed Species ◽  
Wild Mustard ◽  
Activity Density ◽  
Field Pennycress ◽  
Species Activity

We used laboratory and field feeding trials to investigate adult carabid beetle preferences for three brassicaceous weed species (rapeseed, wild mustard, and field pennycress) that are pests in canola. All carabid species preferred seeds of rapeseed most and those of field pennycress least and showed intermediate preference for wild mustard seeds. Beetles highly preferred imbibed seeds of all three weed species. Activity–density of carabids and mean weed seed removal were highly correlated in field plots of canola, with activity–density accounting for 67% of the observed variation in seed removal. Our study indicates that seed consumption among carabids is influenced by several factors, including weed species, physiological state of seeds, and carabid activity–density. Carabid seed predation is significant in canola agroecosystems; therefore, understanding these influences has implications for ecological weed management.

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