The abundance of pollinators around specific landscape Bourget Romain, Walker Mélanie and Howlett Brad ([email protected])

Crop & Food research, Christchurch, New Zealand Introduction The Varroa Destructor was introduced in New Zealand in 2000. This ectoparasite decreases pollination efficiency of the Honey Bee. To limit the economical impact of this mite, others pollinators could be used to crop pollination (Annual Report of the Ministry of Agriculture and Forestry for the year ended, June 2004). Indeed, Indigenous Pollinators Programme (Crop & Food Research) has identified that Diptera (e.g. Calliphoridae, Syrphidae, Sarcophagidae, Bibionidae and Stratiomyidae), and Hymenoptera (e.g. Apidae, Colletidae and Halictidae), can contribute to crop pollination. The goal of the present study is to increase knowledges about these others pollinators and the possibility to use them in crop pollination. Varroa Destructor

Method

Apis mellifera (Honey Bee )

Results

The experiment was to determine what is the pollinators abundance around specific landscape, so :  Six dairy farms were chosen near Christchurch.  In each farm, five places were selected around five different landscapes : a pasture (control), a gorse hedgerow, a pin hedgerow, a passage of water and a garden.

Calliphoridae

 In each place were placed 3 traps. These traps were able to catch all potentials pollinators.

Abundance of Caliphoridae vicina caught in window traps around landscape features showing 95% confidence limits for each mean (y-axis ticks spaced on the ln(count+0.5) scale)  The first observation was that several insect species were found to be more abundant around certain landscape features.

Traps in a garden

 This insects species were often more abundant in gardens. This can be explained by the presence of food and necessary elements for the reproduction of a wide range of pollinators insects, like pollen and nectar of diversified flowers.

 The fly families most observed in gardens were Calliphoridae and Tachinidea.  Pine hedgerows have too a positive impact on the number of pollinators.  In contrast, Apis mellifera and Bombus sp. were least abundant around pine hedgerows and gardens and most abundant around gorse hedgerows and water

Trap in a pasture  Caught insects were sorted in the laboratory and result were analyzed with the software R.

Abundance of Tachinidae caught in window traps around landscape features showing 95% confidence limits for each mean (y-axis ticks spaced on the ln(count+0.5) scale)

Conclusion Agroecosystems are not uniform and several insect species are more abundant around specific landscape features. These results are interesting because some of this insect species can be good pollinators (like Calliphoridae). This study show us that there is a relation between landscapes and pollinators. The next step is to study whether these landscape features significantly influence pollinator occurrence and abundance within crops. Farmers could then use this information for better crop placement and timing to maximize unmanaged pollination services.