Comparing floral resource maps and land cover maps to predict predators and aphid suppression on field bean

Abstract

Context Predatory insects contribute to the natural control of agricultural pests, but also use plant pollen or nectar as supplementary food resources. Resource maps have been proposed as an alternative to land cover maps for prediction of beneficial insects. Objectives We aimed at predicting the abundance of crop pest predating insects and the pest control service they provide with both, detailed flower resource maps and land cover maps. Methods We selected 19 landscapes of 500 m radius and mapped them with both approaches. In the centres of the landscapes, aphid predators – hoverflies (Diptera: Syrphidae), ladybeetles (Coleoptera: Coccinellidae) and lacewings (Neuroptera: Chrysopidae) – were surveyed in experimentally established faba bean phytometers (Vicia faba L. Var. Sutton Dwarf) and their control of introduced black bean aphids (Aphis fabae Scop.) was recorded. Results Landscapes with higher proportions of forest edge as derived from land cover maps supported higher abundance of aphid predators, and high densities of aphid predators reduced aphid infestation on faba bean. Floral resource maps did not significantly predict predator abundance or aphid control services. Conclusions Land cover maps allowed to relate landscape composition with predator abundance, showing positive effects of forest edges. Floral resource maps may have failed to better predict predators because other resources such as overwintering sites or alternative prey potentially play a more important role than floral resources. More research is needed to further improve our understanding of resource requirements beyond floral resource estimations and our understanding of their role for aphid predators at the landscape scale.

Effects of temporal floral resource availability and non-crop habitats on broad bean pollination

“…In our study, seed set was somewhat better predicted by land cover maps than by floral resource maps, although the latter are based on detailed information that more directly and evidently relates to pollinator populations (Roulston and Goodell 2011 ). Similarly, land cover maps explained abundance of aphid predators and related aphid pest control on broad bean better than temporal floral resource maps in Switzerland (Ammann et al 2022 ). This may be due to other above-mentioned parameters that were not assessed in this study (e.g.…”

“…Roulston and Goodell 2011 ). We hypothesize that such floral resource maps predict the crop pollination performance of those pollinators better than land cover maps, which can only indirectly account for such information (Forman 1995 ; Roulston and Goodell 2011 ; Fahrig 2013 ; Eckerter et al 2020 ; Ammann et al 2022 ).…”

Functional identity of dominant species in a predator community prevails over functional diversity in shaping the top‐down control of herbivores

“…In each mesocosm, we introduced 150 aphids and 10 leafhoppers 24 h before the introduction of predators based on realistic densities of these phytophagous species in fields (Ammann et al, 2022; Bosco et al, 1997; Erb et al, 2010). We assessed the number of aphids and leafhoppers after 5 days of predation exposure using a mouth aspirator and careful visual inspections in each mesocosm.…”

Socio-Cultural Issues In Agricultural Modernization: A Case Study of the Food Estate Program in Pulang Pisau Regency

“…In his statement, Huntington (1971) explicitly states that modernization theory views "modern" and "traditional" as two conflicting concepts. Therefore, in the process of modernization, things deemed traditional have no significant role and must be replaced (Ammann et al, 2024).…”