Effects of spatio-temporal resource availability on pollinators and pest-natural enemies in fragmented agricultural landscapes (FRAGMENT III)

• Applicant: Professor Dr. Martin Entling
• Subject Area: Ecology of Land Use ; Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 273454237

• Final Report Year: 2020

Final Report Abstract

Insects in agricultural landscape provide important ecosystem services such as crop pollination and pest control. However, important food resources for insects such as flowers and alternative prey can be rare in modern agricultural landscapes. We investigated effects of food resource availability on insects by (I) identifying the resource use of key insect pollinators and aphid enemies over time, and by (II) studying relationships between the spatio-temporal distribution of resources on insect density, fitness and ecosystem service delivery. Two species of bees (Osmia bicornis, Bombus terrestris) and three species of aphid enemies (Chrysoperla carnea, Coccinella septempunctata, Harmonia axyridis) used pollen mostly from woody plants, and pollen use changed strongly from the early (April-May) to the late (June-July) season. Contrary to our expectation, detailed resource maps did not improve the predictability of bumblebee colony development, the pollination success of field bean, Osmia cornuta abundance or the occurrence of aphid enemies on field beans. Instead, bumblebees, pollination success, Osmia cornuta and aphid enemies were negatively affected by increasing distance to forest or increasing cover of arable land in the landscapes. Only wild bee communities and Osmia bicornis showed the expected positive effect of floral resource availability. This project revealed new information on the spatio-temporal distribution and use of floral resources by ecosystem-service providing insects. The limited ability of floral resource maps to predict insect abundance, fitness or ecosystem services, suggests that more factors than food availability alone affect these insects in agricultural landscapes.

Publications

• (2019) Seasonal shifts and complementary use of pollen sources by key pollinators and aphid enemies in European agricultural landscapes. Journal of Applied Ecology 56: 2431–2442
  Bertrand C, Eckerter P, Ammann L, Entling MH, Gobet E, Herzog F, Mestre L, Tinner W & Albrecht M
  
• (2020) Insights into aphid prey consumption by ladybirds: Optimising field sampling methods and primer design for High Throughput Sequencing. PLOS ONE 15: e0235054
  Ammann L, Moorhouse-Gann R, Bertrand C, Mestre L, Cuff J, Pérez Hidalgo N, Ellison A, Herzog F, Entling MH, Albrecht M & Symondson WOC
  
• (2020) Using temporally resolved floral resource maps to explain bumblebee colony performance in agricultural landscapes. Agronomy 10: 1993
  Eckerter PW, Albus L, Natarajan S, Albrecht M, Ammann L, Gobet E, Herzog F, Tinner W & Entling MH