Rubidium marking reveals different patterns of movement in four ground beetle species (Col., Carabidae) between adjacent alfalfa and maize

Abstract

1 In the north-east Iberian Peninsula, in summer, arable crop landscapes are characterized by a mosaic of alfalfa and maize. Although carabids are among the main predators in both crops, crop management can affect their movement. 2 The main aim of the present study was to measure the movement of the four most abundant carabid species (Calathus fuscipes, Poecilus cupreus, Bembidion lampros and Pseudoophonus rufipes) between adjacent alfalfa and maize before and after alfalfa cutting, using rubidium as a marker. Movement of predators into the herbaceous margin between alfalfa and maize was also assessed. 3 The four carabid species showed bidirectional movements between crops, although the pattern of movement differed between species and was affected by alfalfa cutting. After cutting, the movement of C. fuscipes, P. cupreus and P. rufipes from alfalfa towards maize was higher than in the opposite direction. Bembidion lampros showed a greater degree of movement towards alfalfa than in the opposite direction before cutting and only moved to the margin after cutting. 4 Maize and herbaceous field margins can therefore act as both refuge and donor habitat for carabids, and can help to recolonize alfalfa after cuttings. Growing maize near alfalfa and providing an intercrop refuge habitat may conserve and enhance carabid populations.

Monitoring carabid indicators could reveal environmental impacts of genetically modified maize

“…Carabid communities are characteristic of each habitat (Smith et al ., ). Nevertheless, because maize shared many species with other habitats as recorded in the present study, as well as some others conducted in the area (Núñez, ; Madeira & Pons, ), impacts in GM maize fields would influence other communities. Indeed, species ubiquitous to maize were also present in field margins where sample sizes needed to detect changes were generally lower.…”

Molecular tracking of insect dispersal to verify arthropod predator movement from an alfalfa field to a peach orchard

“…Alfalfa plants were about 50 cm high at the time of study, which is when the crop was ready to be cut. As in other studies (Madeira and Pons, 2016), a strip of the alfalfa field (2.5 m width x 10 m long, and 2-4 m from the peach orchard margin) was sprayed with 8L of the Artemia solution 2h before being cut. The spray was done with a knapsack sprayer (Matabi Super Green 16L, Goizper Spraying, Spain).…”

“…A wide range of marking techniques have been developed to evaluate the dispersal patterns of arthropods (Lavandero et al, 2004;di Lascio et al, 2016;Madeira and Pons, 2016;Jiao et al, 2019;Kenne et al, 2019;Tavares et al, 2019;Hagler and Machtley, 2020). El Sheikha (2019) reviews the advantages and disadvantages of several tracking techniques.…”

Is the effectiveness of policy-driven mitigation measures on carabid populations driven by landscape and farmland heterogeneity? Applying a modelling approach in the Dutch agroecosystems

“…B . lampros can find food and reproduce in various crop types, including cereals, maize, alfalfa, beans, potatoes, oilseed rape and grasslands/pastures [ 42 , 43 ]. It feeds on Collembola, Diptera, mites, earthworms and small beetles [ 39 ].…”

“…The end of hibernation and movement from overwintering sites into field interiors is triggered by increase in air temperatures on early spring [41]. B. lampros can find food and reproduce in various crop types, including cereals, maize, alfalfa, beans, potatoes, oilseed rape and grasslands/pastures [42,43]. It feeds on Collembola, Diptera, mites, earthworms and small beetles [39].…”