Abundance and diversity of beneficial arthropods in conventional and “organic” carrot crops in New Zealand

Abstract

The abundance and ecological diversity of selected groups of beneficial arthropods were compared between 16 organic and 17 conventional carrot (Daucus carota L.) fields in the Manawatu (North Island) and Canterbury and Nelson (South Island) areas of New Zealand using a suction sampler. Organic fields had significantly higher numbers of Hymenoptera: Parasitica, Staphylinidae (Coleoptera), and Neuroptera (Hemerobiidae) compared with conventional fields. Organic fields also had a significantly more diverse predatory and parasitic community than did conventional fields, as measured by the “Sequential Comparison Index”. The implications of these results for biological control of pests in conventional and organic crops are discussed.

Keywords:

• organic crops
• conventional crops
• arthropods
• diversity
• populations
• carrots

Notes

To whom correspondence is to be addressed.