Movement of three aphidophagous ladybird species between alfalfa and maize revealed by carbon and nitrogen stable isotope analysis

Abstract

The movement between alfalfa and maize of three of the most common aphidophagous coccinellids in southern Europe was determined using carbon and nitrogen stable isotope analysis at four periods during the growing season. The isotope analysis revealed movement between alfalfa and maize but patterns were different between the three species. While Coccinella septempunctata L. (Coleoptera: Coccinellidae) only moved from alfalfa to maize, Propylea quatuordecimpunctata L. (Coleoptera: Coccinellidae) continuously dispersed between the two adjacent crops. Hippodamia variegata Goeze (Coleoptera: Coccinellidae) showed an intermediate pattern. Results suggest that, while alfalfa acts as a source of the three species to maize, maize also plays a role as a source of P. quatuordecimpunctata and H. variegata to alfalfa. The specific movement traits that emerged for the three coccinellid species suggest that crop management affects them differently and point out that the association between crops is very valuable for improving coccinellid biological control services.

Development of a PCR‐based method to monitor arthropod dispersal in agroecosystems: Macrolophus pygmaeus (Hemiptera: Miridae) from banker plants to tomato crops

“…For this, it is essential to understand their dispersal patterns, habitat preferences and spatial distribution by tracking their movements (Corbett, 1998;Thomas, 2001). A wide variety of marking techniques, like paints, inks, dyes, powders, or rare and trace elements (e.g., rubidium), have been developed over the years to study the dispersal patterns of many arthropods (Lavandero et al, 2004a;Di Lascio et al, 2016;. They are effective, but most of them require a strong effort to capture and mark all the specimens, and/or they are rela-Correspondence: Nuria Agustí, IRTA, Carretera de Cabrils, Km 2, 08348 Cabrils, Barcelona, Spain.…”

Adjacent habitat type affects the movement of predators suppressing soybean aphids

“…Zumoffen, Signorini [7], also using bi-directional Malaise traps, found a net movement of aphid parasitoids (mainly Braconidae) from borders with natural vegetation towards wheat and alfalfa crops in Argentina. Marking methods suggest that dispersal of lady beetles within and between crops is affected by the number of aphids in the habitats studied [8,9], the crop type and phenology [10] and the lady beetle species [11]. Altogether, this previous research indicates the need for system-specific studies to quantify the movement of natural enemies between crops and other habitats to assess associated pest control services.…”

Rapid PCR-based method for herbivore dietary evaluation using plant-specific primers

“…Further, understanding the diet composition of polyphagous pests in agroecosystems is a challenging task using direct observation of feeding in agricultural fields, due to the time (e.g., nocturnal) and location of pest activity (e.g., under soil feeding) [ 19 ]. At the landscape scale, several techniques including bi-directional malaise traps [ 21 ], molecular mark-recapture [ 22 – 25 ] and isotope techniques [ 25 – 28 ] have been used to monitor the movement of polyphagous pests and their natural enemies between habitats, to understand how habitat preference or habitat composition shapes pest and natural enemy movement. However, while these techniques could provide useful information regarding the movement of pests and natural enemies among crop and habitat patches in the landscape, it does not reveal the diet breadth of polyphagous pests and natural enemies, or their intention for visiting different crop patches in the landscape (e.g., to feed on insect prey or plant carbohydrate resources).…”