Pollinators and other insects associated with blueberry and canola crops

Study Extent

The study was carried out in southern Chile, in the Araucanía Region (38.2°S - 39.3°S; Fig. S1). Pan traps were placed during flowering in eight blueberry (Vaccinium corymbosum) orchards (= crop fields) between September-October 2019 and in eight canola (Brassica napus) fields between October-November 2019. In both cases, the same crop species cultivar was sampled to reduce the confounding effects of different cultivars on the results. Blueberry orchards had a mean size of 35.38  12.66 ha (mean +- SE), while canola orchards had a mean size of 130.50 +- 54.36 ha. Sampled blueberry orchards were at least 8 km apart, while canola fields were at least 4.7 km apart from each other.

Sampling

We used three pan trap colors: blue (430-500 nm), white (400-700 nm), and yellow (565-580 nm). In each orchard, we placed three sets of pan traps at the crop border (0 - 10 m) and three sets within the crop (50-70 m from the border; in some smaller blueberry orchards, it was not possible to place them 50 m from the field border, in such locations we maximized the distance to the border as much as possible; Fig. S2). Thus, we placed 18 pan traps at each orchard, nine (i.e., three sets of yellow, white, and blue plates) in the edge of the crop and nine in the center, making a total of 144 pan traps per crop type, and 288 pan traps overall. Pan traps (18 cm in diameter and 10 cm in depth, Forfest, Brazil) were placed twice during flowering in blueberry (sampling bouts were separated by at least five days) orchards and once during flowering in the canola fields on days with good weather (i.e., no rain). Each pan trap set consisted of three traps of different colors (i.e., white, yellow, and blue) separated ~3m from each other (following FAO recommendations [21]). Pan traps were placed 50 cm above the ground and secured using a wooden stake to fix them and avoid mechanical effects from the wind. We placed pan traps in the morning, filled them with water and a few drops of odorless soap, and left them for 24h in the field. After that, we collected the insects captured by the pan traps and preserved them in recipients with 70% ethanol, separating them according to trap color and position (center or border). In our study area, blueberries bloomed early in spring, and canola started to bloom a few weeks after blueberry flowering was over. We conducted pan trap sampling in blueberry crops between September 16th and October 5th 2019, and between October 30th and November 8th 2019, in the canola crops.

Quality Control

Data was checked for taxonomic correctness and completeness.

Method steps

1. A total of 3375 insect specimens were obtained, belonging to 127 insect species grouped in 58 families, which were examined by an expert entomologist (CJP) and identified at the lowest taxonomic level possible, based on the Catalogue of Life (https://www.catalogueoflife.org/) database.

1. Asilidae
   rank: family
2. Coleoptera
   rank: order
3. Arthropoda
   rank: phylum
4. Anthomyiidae
   rank: family
5. Melyridae
   rank: family
6. Insecta
   rank: class
7. Diptera
   rank: order
8. Muscidae
   rank: family
9. Empididae
   rank: family
10. Syrphidae
    rank: family
11. Mycetophilidae
    rank: family
12. Hymenoptera
    rank: order
13. Chironomidae
    rank: family
14. Staphylinidae
    rank: family
15. Apidae
    rank: family
16. Animalia
    rank: kingdom
17. Formicidae
    rank: family

Southern Chile, Araucania Region