D3201: Insect biodiversity in the organic almond and pistachio orchard

The diversity and abundance of insects in organic almond and pistachio orchards were examined during the crop growing season at five sites, from April through August 2022. Biodiverse orchards offer growers benefits such as improved soil health and reduced insecticide applications. Sweep net samples were used to collect insects from the vegetation. At each site, 4 sweep samples were collected. Each sample was placed in a ziplock bag and frozen for later identification. In the lab, each sample bag had insects sorted and identified. Insects were sorted to Order, and then Family when possible; all were sorted to morphospecies. Data were used to calculate Alpha diversity, the number of unique species, for each site and each date. Beta diversity was calculated to compare the diversity between sites and between farms. Results include the number and percent insects identified to Order, and the number and percent of species in each Order. The study found that Diptera were most abundant, followed by Homoptera. Total insect diversity and abundance was highest in late April, before May pest control sprays occurred in the orchards. The diversity and abundance of Hymenoptera and Hemiptera through the season are discussed, since many are beneficial or pests, respectively. A future goal is to determine whether biodiverse orchards can provide levels of pest control which are comparable to conventional orchards.