|RIJAL,, JHALENDRA - University Of California Agriculture And Natural Resources (UCANR)
|GYAWALY, SUDAN - University Of California Agriculture And Natural Resources (UCANR)
Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/4/2023
Publication Date: N/A
Interpretive Summary: In California almonds, there are many types of bugs that can cause damage to the growing nuts. Some of the most common bugs are leaffooted bugs and green stink bugs. Recently, the brown marmorated stink bug (BMSB) causing damage to almonds was found in some areas of California. This study evaluated the damage these bugs were causing to almonds at the edge of the orchard compared to the inside. The BMSB and other bugs were found to cause more damage to almonds at the edge of the orchard than inside. This means that it's important to manage these bugs at the edge of the orchard to protect the almonds from damage.
Technical Abstract: Multiple species of hemipteran insects are present in almond orchards, and these pests can cause significant damage to the growing nuts. In northern as well as southern San Joaquin Valleys of California, most common hemipteran pests in almonds include leaffooted bug, Leptoglossus spp. and green stink bug, Chinavia hilaris. Recently, we detected the invasive brown marmorated stink bug (BMSB), Halyomorpha halys, prevalent in northern San Joaquin Valley and some areas of the southern San Joaquin Valley. Here, we investigated the edge effect of BMSB and other hemipteran damage in almonds. We found that BMSB is a heavily border-driven pest as the degree of damage to the almond was substantially higher in the orchard edge (=border row) compared to the internal part of the orchard. For the gummy kernel, percent damage at the edge (17.0%) was statistically higher compared to all other distances from the border (i.e., 12.2m, 24.4m, 36.6m, 48.8m, 61.0m). Based on the nut damage evaluated at harvest from the multiple orchards, we found that hemipteran damage was two times greater in the orchard edge compared to the interior of the orchard damage based on the harvest sampling evaluation conducted from pollinizer (n =13) and Nonpareil (n =17) cultivars. The integrated management of hemipteran pests is discussed in light of these findings.