D3273: Hemiptera diversity in almond orchards and association with crop phenology

Almonds are an economically important crop in California, with 1.56 million acres in production and an estimated value of $11 billion dollars annually. Some key insect pests in orchards include the navel orangeworm and several Hemipterans, among others. Hemipteran feeding during almond development can cause damage and crop loss, they are some of the most economically damaging pests to crops. However, there are also beneficial Hemipterans in orchards. The aim of this study was to identify the hemipteran beneficial and pest insect species throughout the growing season within almond orchards in California’s San Joaquin Valley. Insects were collected in ten orchards using sweep nets and sorted to insect order and then into morphospecies. Each insect was photographed, and a tentative identification was made. Each individual was then used for DNA extraction and sequencing of the mitochondrial DNA COI gene. The resulting sequences were compared to GenBank for specimen identification. Genetic diversity was further investigated for Halyomorpha halys (BMSB), Lygus spp., and Orius spp. To assess the pest potential of the different species, the collection date of each insect species was examined in relation to the phenology and vulnerability of the developing almond crop. There was a rich diversity of Hemiptera collected in orchards. Species identification is important, as it can trace the origin of introduced species, uncover the presence of cryptic species, and examine genetic variability, which are all valuable to sustainable integrated pest management.